Minimize amount of fake `DefId`s used in rustdoc

12 files changed, 55 insertions, 90 deletions

diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index e1dde8eeaf8..feeb03b1b67 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -533,8 +533,7 @@ impl Clean<Generics> for hir::Generics<'_> {
                 match param.kind {
                     GenericParamDefKind::Lifetime => unreachable!(),
                     GenericParamDefKind::Type { did, ref bounds, .. } => {
-                        cx.impl_trait_bounds
-                            .insert(FakeDefId::new_real(did).into(), bounds.clone());
+                        cx.impl_trait_bounds.insert(did.into(), bounds.clone());
                     }
                     GenericParamDefKind::Const { .. } => unreachable!(),
                 }
@@ -615,7 +614,7 @@ impl<'a, 'tcx> Clean<Generics> for (&'a ty::Generics, ty::GenericPredicates<'tcx
             .collect::<Vec<GenericParamDef>>();
 
         // param index -> [(DefId of trait, associated type name, type)]
-        let mut impl_trait_proj = FxHashMap::<u32, Vec<(FakeDefId, Symbol, Ty<'tcx>)>>::default();
+        let mut impl_trait_proj = FxHashMap::<u32, Vec<(DefId, Symbol, Ty<'tcx>)>>::default();
 
         let where_predicates = preds
             .predicates
@@ -687,13 +686,7 @@ impl<'a, 'tcx> Clean<Generics> for (&'a ty::Generics, ty::GenericPredicates<'tcx
                 if let Some(proj) = impl_trait_proj.remove(&idx) {
                     for (trait_did, name, rhs) in proj {
                         let rhs = rhs.clean(cx);
-                        simplify::merge_bounds(
-                            cx,
-                            &mut bounds,
-                            trait_did.expect_real(),
-                            name,
-                            &rhs,
-                        );
+                        simplify::merge_bounds(cx, &mut bounds, trait_did, name, &rhs);
                     }
                 }
             } else {
@@ -1183,8 +1176,7 @@ fn clean_qpath(hir_ty: &hir::Ty<'_>, cx: &mut DocContext<'_>) -> Type {
                 if let Some(new_ty) = cx.ty_substs.get(&did).cloned() {
                     return new_ty;
                 }
-                if let Some(bounds) = cx.impl_trait_bounds.remove(&FakeDefId::new_real(did).into())
-                {
+                if let Some(bounds) = cx.impl_trait_bounds.remove(&did.into()) {
                     return ImplTrait(bounds);
                 }
             }
diff --git a/src/librustdoc/clean/types.rs b/src/librustdoc/clean/types.rs
index f0e04018242..edd3d77eeb7 100644
--- a/src/librustdoc/clean/types.rs
+++ b/src/librustdoc/clean/types.rs
@@ -73,10 +73,6 @@ impl FakeDefId {
         Self::Fake(DefIndex::from(id), krate)
     }
 
-    crate fn new_real(id: DefId) -> Self {
-        Self::Real(id)
-    }
-
     #[inline]
     crate fn is_local(self) -> bool {
         match self {
@@ -470,7 +466,7 @@ impl Item {
             .filter_map(|ItemLink { link: s, link_text, did, ref fragment }| {
                 match did {
                     Some(did) => {
-                        if let Some((mut href, ..)) = href(did.expect_real(), cx) {
+                        if let Some((mut href, ..)) = href(did.clone(), cx) {
                             if let Some(ref fragment) = *fragment {
                                 href.push('#');
                                 href.push_str(fragment);
@@ -972,7 +968,7 @@ crate struct ItemLink {
     /// This may not be the same as `link` if there was a disambiguator
     /// in an intra-doc link (e.g. \[`fn@f`\])
     pub(crate) link_text: String,
-    pub(crate) did: Option<FakeDefId>,
+    pub(crate) did: Option<DefId>,
     /// The url fragment to append to the link
     pub(crate) fragment: Option<String>,
 }
diff --git a/src/librustdoc/core.rs b/src/librustdoc/core.rs
index b43916f9f33..2930c3c5fb7 100644
--- a/src/librustdoc/core.rs
+++ b/src/librustdoc/core.rs
@@ -576,12 +576,12 @@ impl<'tcx> Visitor<'tcx> for EmitIgnoredResolutionErrors<'tcx> {
 /// for `impl Trait` in argument position.
 #[derive(Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
 crate enum ImplTraitParam {
-    DefId(FakeDefId),
+    DefId(DefId),
     ParamIndex(u32),
 }
 
-impl From<FakeDefId> for ImplTraitParam {
-    fn from(did: FakeDefId) -> Self {
+impl From<DefId> for ImplTraitParam {
+    fn from(did: DefId) -> Self {
         ImplTraitParam::DefId(did)
     }
 }
diff --git a/src/librustdoc/formats/cache.rs b/src/librustdoc/formats/cache.rs
index 50496f32009..5734a4a98e2 100644
--- a/src/librustdoc/formats/cache.rs
+++ b/src/librustdoc/formats/cache.rs
@@ -67,7 +67,7 @@ crate struct Cache {
     /// When rendering traits, it's often useful to be able to list all
     /// implementors of the trait, and this mapping is exactly, that: a mapping
     /// of trait ids to the list of known implementors of the trait
-    crate implementors: FxHashMap<FakeDefId, Vec<Impl>>,
+    crate implementors: FxHashMap<DefId, Vec<Impl>>,
 
     /// Cache of where external crate documentation can be found.
     crate extern_locations: FxHashMap<CrateNum, ExternalLocation>,
@@ -299,7 +299,7 @@ impl<'a, 'tcx> DocFolder for CacheBuilder<'a, 'tcx> {
                             desc: item
                                 .doc_value()
                                 .map_or_else(String::new, |x| short_markdown_summary(&x.as_str())),
-                            parent: parent.map(FakeDefId::new_real),
+                            parent,
                             parent_idx: None,
                             search_type: get_index_search_type(&item, &self.empty_cache, self.tcx),
                             aliases: item.attrs.get_doc_aliases(),
diff --git a/src/librustdoc/html/render/cache.rs b/src/librustdoc/html/render/cache.rs
index 57520a1a1fb..3e056c4b67a 100644
--- a/src/librustdoc/html/render/cache.rs
+++ b/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,
                 })
             })
diff --git a/src/librustdoc/html/render/mod.rs b/src/librustdoc/html/render/mod.rs
index 5b54b32e4dd..e4dbf145866 100644
--- a/src/librustdoc/html/render/mod.rs
+++ b/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()
diff --git a/src/librustdoc/html/render/print_item.rs b/src/librustdoc/html/render/print_item.rs
index 20e82cf2caf..ff639cb2924 100644
--- a/src/librustdoc/html/render/print_item.rs
+++ b/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();
diff --git a/src/librustdoc/html/render/write_shared.rs b/src/librustdoc/html/render/write_shared.rs
index d0518cb6862..c25a73f58eb 100644
--- a/src/librustdoc/html/render/write_shared.rs
+++ b/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
diff --git a/src/librustdoc/json/conversions.rs b/src/librustdoc/json/conversions.rs
index d2349b42ae9..5ac43c73646 100644
--- a/src/librustdoc/json/conversions.rs
+++ b/src/librustdoc/json/conversions.rs
@@ -14,9 +14,8 @@ use rustc_span::Pos;
 
 use rustdoc_json_types::*;
 
-use crate::clean;
 use crate::clean::utils::print_const_expr;
-use crate::clean::FakeDefId;
+use crate::clean::{self, FakeDefId};
 use crate::formats::item_type::ItemType;
 use crate::json::JsonRenderer;
 use std::collections::HashSet;
@@ -31,7 +30,7 @@ impl JsonRenderer<'_> {
             .into_iter()
             .flatten()
             .filter_map(|clean::ItemLink { link, did, .. }| {
-                did.map(|did| (link.clone(), from_def_id(did)))
+                did.map(|did| (link.clone(), from_def_id(did.into())))
             })
             .collect();
         let docs = item.attrs.collapsed_doc_value();
diff --git a/src/librustdoc/json/mod.rs b/src/librustdoc/json/mod.rs
index d56acad60c0..f8bd9710813 100644
--- a/src/librustdoc/json/mod.rs
+++ b/src/librustdoc/json/mod.rs
@@ -12,13 +12,14 @@ use std::path::PathBuf;
 use std::rc::Rc;
 
 use rustc_data_structures::fx::FxHashMap;
+use rustc_hir::def_id::DefId;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::Session;
 
 use rustdoc_json_types as types;
 
 use crate::clean;
-use crate::clean::{ExternalCrate, FakeDefId};
+use crate::clean::ExternalCrate;
 use crate::config::RenderOptions;
 use crate::error::Error;
 use crate::formats::cache::Cache;
@@ -42,7 +43,7 @@ impl JsonRenderer<'tcx> {
         self.tcx.sess
     }
 
-    fn get_trait_implementors(&mut self, id: FakeDefId) -> Vec<types::Id> {
+    fn get_trait_implementors(&mut self, id: DefId) -> Vec<types::Id> {
         Rc::clone(&self.cache)
             .implementors
             .get(&id)
@@ -59,10 +60,10 @@ impl JsonRenderer<'tcx> {
             .unwrap_or_default()
     }
 
-    fn get_impls(&mut self, id: FakeDefId) -> Vec<types::Id> {
+    fn get_impls(&mut self, id: DefId) -> Vec<types::Id> {
         Rc::clone(&self.cache)
             .impls
-            .get(&id.expect_real())
+            .get(&id)
             .map(|impls| {
                 impls
                     .iter()
@@ -163,11 +164,11 @@ impl<'tcx> FormatRenderer<'tcx> for JsonRenderer<'tcx> {
         let id = item.def_id;
         if let Some(mut new_item) = self.convert_item(item) {
             if let types::ItemEnum::Trait(ref mut t) = new_item.inner {
-                t.implementors = self.get_trait_implementors(id)
+                t.implementors = self.get_trait_implementors(id.expect_real())
             } else if let types::ItemEnum::Struct(ref mut s) = new_item.inner {
-                s.impls = self.get_impls(id)
+                s.impls = self.get_impls(id.expect_real())
             } else if let types::ItemEnum::Enum(ref mut e) = new_item.inner {
-                e.impls = self.get_impls(id)
+                e.impls = self.get_impls(id.expect_real())
             }
             let removed = self.index.borrow_mut().insert(from_def_id(id), new_item.clone());
 
diff --git a/src/librustdoc/passes/collect_intra_doc_links.rs b/src/librustdoc/passes/collect_intra_doc_links.rs
index 8838dc57d5a..88207b67743 100644
--- a/src/librustdoc/passes/collect_intra_doc_links.rs
+++ b/src/librustdoc/passes/collect_intra_doc_links.rs
@@ -30,9 +30,7 @@ use std::convert::{TryFrom, TryInto};
 use std::mem;
 use std::ops::Range;
 
-use crate::clean::{
-    self, utils::find_nearest_parent_module, Crate, FakeDefId, Item, ItemLink, PrimitiveType,
-};
+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};
@@ -248,7 +246,7 @@ enum AnchorFailure {
 
 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
 struct ResolutionInfo {
-    module_id: FakeDefId,
+    module_id: DefId,
     dis: Option<Disambiguator>,
     path_str: String,
     extra_fragment: Option<String>,
@@ -274,7 +272,7 @@ struct LinkCollector<'a, 'tcx> {
     ///
     /// The last module will be used if the parent scope of the current item is
     /// unknown.
-    mod_ids: Vec<FakeDefId>,
+    mod_ids: Vec<DefId>,
     /// This is used to store the kind of associated items,
     /// because `clean` and the disambiguator code expect them to be different.
     /// See the code for associated items on inherent impls for details.
@@ -861,7 +859,7 @@ impl<'a, 'tcx> DocFolder for LinkCollector<'a, 'tcx> {
         let inner_docs = item.inner_docs(self.cx.tcx);
 
         if item.is_mod() && inner_docs {
-            self.mod_ids.push(item.def_id);
+            self.mod_ids.push(item.def_id.expect_real());
         }
 
         // We want to resolve in the lexical scope of the documentation.
@@ -888,7 +886,7 @@ impl<'a, 'tcx> DocFolder for LinkCollector<'a, 'tcx> {
 
         Some(if item.is_mod() {
             if !inner_docs {
-                self.mod_ids.push(item.def_id);
+                self.mod_ids.push(item.def_id.expect_real());
             }
 
             let ret = self.fold_item_recur(item);
@@ -1070,11 +1068,8 @@ impl LinkCollector<'_, '_> {
         // we've already pushed this node onto the resolution stack but
         // for outer comments we explicitly try and resolve against the
         // parent_node first.
-        let base_node = if item.is_mod() && inner_docs {
-            self.mod_ids.last().copied()
-        } else {
-            parent_node.map(|id| FakeDefId::new_real(id))
-        };
+        let base_node =
+            if item.is_mod() && inner_docs { self.mod_ids.last().copied() } else { parent_node };
 
         let mut module_id = if let Some(id) = base_node {
             id
@@ -1119,7 +1114,7 @@ impl LinkCollector<'_, '_> {
                 resolved_self = format!("self::{}", &path_str["crate::".len()..]);
                 path_str = &resolved_self;
             }
-            module_id = FakeDefId::new_real(DefId { krate, index: CRATE_DEF_INDEX });
+            module_id = DefId { krate, index: CRATE_DEF_INDEX };
         }
 
         let (mut res, mut fragment) = self.resolve_with_disambiguator_cached(
@@ -1180,8 +1175,8 @@ impl LinkCollector<'_, '_> {
             report_diagnostic(self.cx.tcx, BROKEN_INTRA_DOC_LINKS, &msg, &diag_info, callback);
         };
 
-        let verify = |kind: DefKind, id: FakeDefId| {
-            let (kind, id) = self.kind_side_channel.take().unwrap_or((kind, id.expect_real()));
+        let verify = |kind: DefKind, id: DefId| {
+            let (kind, id) = self.kind_side_channel.take().unwrap_or((kind, id));
             debug!("intra-doc link to {} resolved to {:?} (id: {:?})", path_str, res, id);
 
             // Disallow e.g. linking to enums with `struct@`
@@ -1345,7 +1340,7 @@ impl LinkCollector<'_, '_> {
 
         match disambiguator.map(Disambiguator::ns) {
             Some(expected_ns @ (ValueNS | TypeNS)) => {
-                match self.resolve(path_str, expected_ns, base_node.expect_real(), extra_fragment) {
+                match self.resolve(path_str, expected_ns, base_node, extra_fragment) {
                     Ok(res) => Some(res),
                     Err(ErrorKind::Resolve(box mut kind)) => {
                         // We only looked in one namespace. Try to give a better error if possible.
@@ -1354,12 +1349,9 @@ impl LinkCollector<'_, '_> {
                             // FIXME: really it should be `resolution_failure` that does this, not `resolve_with_disambiguator`
                             // See https://github.com/rust-lang/rust/pull/76955#discussion_r493953382 for a good approach
                             for &new_ns in &[other_ns, MacroNS] {
-                                if let Some(res) = self.check_full_res(
-                                    new_ns,
-                                    path_str,
-                                    base_node.expect_real(),
-                                    extra_fragment,
-                                ) {
+                                if let Some(res) =
+                                    self.check_full_res(new_ns, path_str, base_node, extra_fragment)
+                                {
                                     kind = ResolutionFailure::WrongNamespace { res, expected_ns };
                                     break;
                                 }
@@ -1381,14 +1373,9 @@ impl LinkCollector<'_, '_> {
                 // Try everything!
                 let mut candidates = PerNS {
                     macro_ns: self
-                        .resolve_macro(path_str, base_node.expect_real())
+                        .resolve_macro(path_str, base_node)
                         .map(|res| (res, extra_fragment.clone())),
-                    type_ns: match self.resolve(
-                        path_str,
-                        TypeNS,
-                        base_node.expect_real(),
-                        extra_fragment,
-                    ) {
+                    type_ns: match self.resolve(path_str, TypeNS, base_node, extra_fragment) {
                         Ok(res) => {
                             debug!("got res in TypeNS: {:?}", res);
                             Ok(res)
@@ -1399,12 +1386,7 @@ impl LinkCollector<'_, '_> {
                         }
                         Err(ErrorKind::Resolve(box kind)) => Err(kind),
                     },
-                    value_ns: match self.resolve(
-                        path_str,
-                        ValueNS,
-                        base_node.expect_real(),
-                        extra_fragment,
-                    ) {
+                    value_ns: match self.resolve(path_str, ValueNS, base_node, extra_fragment) {
                         Ok(res) => Ok(res),
                         Err(ErrorKind::AnchorFailure(msg)) => {
                             anchor_failure(self.cx, diag, msg);
@@ -1460,17 +1442,14 @@ impl LinkCollector<'_, '_> {
                 }
             }
             Some(MacroNS) => {
-                match self.resolve_macro(path_str, base_node.expect_real()) {
+                match self.resolve_macro(path_str, base_node) {
                     Ok(res) => Some((res, extra_fragment.clone())),
                     Err(mut kind) => {
                         // `resolve_macro` only looks in the macro namespace. Try to give a better error if possible.
                         for &ns in &[TypeNS, ValueNS] {
-                            if let Some(res) = self.check_full_res(
-                                ns,
-                                path_str,
-                                base_node.expect_real(),
-                                extra_fragment,
-                            ) {
+                            if let Some(res) =
+                                self.check_full_res(ns, path_str, base_node, extra_fragment)
+                            {
                                 kind =
                                     ResolutionFailure::WrongNamespace { res, expected_ns: MacroNS };
                                 break;
diff --git a/src/librustdoc/passes/collect_trait_impls.rs b/src/librustdoc/passes/collect_trait_impls.rs
index 90b797da249..9b7e10b2688 100644
--- a/src/librustdoc/passes/collect_trait_impls.rs
+++ b/src/librustdoc/passes/collect_trait_impls.rs
@@ -126,7 +126,7 @@ crate fn collect_trait_impls(krate: Crate, cx: &mut DocContext<'_>) -> Crate {
         // Since only the `DefId` portion of the `Type` instances is known to be same for both the
         // `Deref` target type and the impl for type positions, this map of types is keyed by
         // `DefId` and for convenience uses a special cleaner that accepts `DefId`s directly.
-        if cleaner.keep_impl_with_def_id(&FakeDefId::new_real(*type_did)) {
+        if cleaner.keep_impl_with_def_id(FakeDefId::Real(*type_did)) {
             add_deref_target(&type_did_to_deref_target, &mut cleaner, type_did);
         }
     }
@@ -206,13 +206,13 @@ impl BadImplStripper {
         } else if let Some(prim) = ty.primitive_type() {
             self.prims.contains(&prim)
         } else if let Some(did) = ty.def_id() {
-            self.keep_impl_with_def_id(&did.into())
+            self.keep_impl_with_def_id(did.into())
         } else {
             false
         }
     }
 
-    fn keep_impl_with_def_id(&self, did: &FakeDefId) -> bool {
-        self.items.contains(did)
+    fn keep_impl_with_def_id(&self, did: FakeDefId) -> bool {
+        self.items.contains(&did)
     }
 }