[BROKEN] fix the regression from rust-lang#77820

This currently breaks, see
rust-lang#77820 (comment).

```
DEBUG rustdoc::clean::inline build_impl: impl Some(DefId(1:7424 ~ std[7f8a]::os::linux::fs::MetadataExt)) for Some(DefId(1:7039 ~ std[7f8a]::fs::Metadata))
DEBUG rustdoc::clean::types name=None, def_id=DefId(1:7442 ~ std[7f8a]::os::linux::fs::{impl#0})
thread 'rustc' panicked at 'only local items can have restricted visibility (while calculating vis of DefId(1:7420 ~ std[7f8a]::os::linux::fs))', src/librustdoc/clean/mod.rs:1762:51
```

```
stack backtrace:
   0: rust_begin_unwind
   1: std::panicking::begin_panic_fmt
   2: rustdoc::clean::ty_visibility::{{closure}}
   3: rustdoc::clean::ty_visibility
   4: rustdoc::clean::types::Item::from_def_id_and_parts
   5: rustdoc::clean::inline::build_impl
   6: rustc_session::utils::<impl rustc_session::session::Session>::time
   7: rustdoc::passes::collect_trait_impls::collect_trait_impls
   8: rustc_session::utils::<impl rustc_session::session::Session>::time
   9: rustdoc::core::run_global_ctxt
  10: rustc_interface::passes::QueryContext::enter
  11: rustc_session::utils::<impl rustc_session::session::Session>::time
  12: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter
  13: rustc_span::with_source_map
  14: rustc_interface::interface::create_compiler_and_run
  15: rustdoc::core::run_core
  16: rustdoc::main_options
  17: scoped_tls::ScopedKey<T>::set
  18: rustc_span::with_session_globals
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
```

Author: jyn514

src/librustdoc/clean/mod.rs

@@ -1731,7 +1731,7 @@ impl Clean<Item> for hir::StructField<'_> {
             cx,
         );
         // Don't show `pub` for fields on enum variants; they are always public
-        Item { visibility: self.vis.clean(cx), ..what_rustc_thinks }
+        Item { visibility: hir_visibility(&self.vis, self.hir_id, cx), ..what_rustc_thinks }
     }
 }
 
@@ -1744,34 +1744,34 @@ impl Clean<Item> for ty::FieldDef {
             cx,
         );
         // Don't show `pub` for fields on enum variants; they are always public
-        Item { visibility: self.vis.clean(cx), ..what_rustc_thinks }
-    }
-}
-
-impl Clean<Visibility> for hir::Visibility<'_> {
-    fn clean(&self, cx: &DocContext<'_>) -> Visibility {
-        match self.node {
-            hir::VisibilityKind::Public => Visibility::Public,
-            hir::VisibilityKind::Inherited => Visibility::Inherited,
-            hir::VisibilityKind::Crate(_) => {
-                let krate = DefId::local(CRATE_DEF_INDEX);
-                Visibility::Restricted(krate, cx.tcx.def_path(krate))
-            }
-            hir::VisibilityKind::Restricted { ref path, .. } => {
-                let path = path.clean(cx);
-                let did = register_res(cx, path.res);
-                Visibility::Restricted(did, cx.tcx.def_path(did))
-            }
-        }
-    }
-}
-
-impl Clean<Visibility> for ty::Visibility {
-    fn clean(&self, cx: &DocContext<'_>) -> Visibility {
-        match *self {
-            ty::Visibility::Public => Visibility::Public,
-            ty::Visibility::Invisible => Visibility::Inherited,
-            ty::Visibility::Restricted(module) => {
+        let hir_id = self.did.as_local().map(|local| cx.tcx.hir().local_def_id_to_hir_id(local));
+        Item { visibility: ty_visibility(self.vis, hir_id, cx), ..what_rustc_thinks }
+    }
+}
+
+fn hir_visibility(
+    vis: &hir::Visibility<'_>,
+    hir_id: hir::HirId,
+    cx: &DocContext<'_>,
+) -> Visibility {
+    // FIXME: I think this handles `Inherited` wrong
+    ty_visibility(ty::Visibility::from_hir(vis, hir_id, cx.tcx), Some(hir_id), cx)
+}
+
+fn ty_visibility(
+    vis: ty::Visibility,
+    hir_id: Option<hir::HirId>,
+    cx: &DocContext<'_>,
+) -> Visibility {
+    match vis {
+        ty::Visibility::Public => Visibility::Public,
+        ty::Visibility::Invisible => Visibility::Inherited,
+        ty::Visibility::Restricted(module) => {
+            let hir_id = hir_id.unwrap_or_else(|| panic!("only local items can have restricted visibility (while calculating vis of {:?})", module));
+            let parent = cx.tcx.parent_module(hir_id).to_def_id();
+            if parent == module {
+                Visibility::RestrictSelf
+            } else {
                 Visibility::Restricted(module, cx.tcx.def_path(module))
             }
         }
@@ -2093,7 +2093,7 @@ impl Clean<Vec<Item>> for doctree::Impl<'_> {
             attrs: self.attrs.clean(cx),
             source: self.span.clean(cx),
             def_id: def_id.to_def_id(),
-            visibility: self.vis.clean(cx),
+            visibility: hir_visibility(self.vis, self.id, cx),
             stability: cx.stability(self.id),
             deprecation: cx.deprecation(self.id).clean(cx),
             inner: ImplItem(Impl {
@@ -2149,7 +2149,7 @@ impl Clean<Vec<Item>> for doctree::ExternCrate<'_> {
             attrs: self.attrs.clean(cx),
             source: self.span.clean(cx),
             def_id: DefId { krate: self.cnum, index: CRATE_DEF_INDEX },
-            visibility: self.vis.clean(cx),
+            visibility: hir_visibility(self.vis, self.hir_id, cx),
             stability: None,
             deprecation: None,
             inner: ExternCrateItem(self.name.clean(cx), self.path.clone()),
@@ -2220,7 +2220,7 @@ impl Clean<Vec<Item>> for doctree::Import<'_> {
                         attrs: self.attrs.clean(cx),
                         source: self.span.clean(cx),
                         def_id: cx.tcx.hir().local_def_id(self.id).to_def_id(),
-                        visibility: self.vis.clean(cx),
+                        visibility: hir_visibility(self.vis, self.id, cx),
                         stability: None,
                         deprecation: None,
                         inner: ImportItem(Import::new_simple(
@@ -2240,7 +2240,7 @@ impl Clean<Vec<Item>> for doctree::Import<'_> {
             attrs: self.attrs.clean(cx),
             source: self.span.clean(cx),
             def_id: DefId::local(CRATE_DEF_INDEX),
-            visibility: self.vis.clean(cx),
+            visibility: hir_visibility(self.vis, self.id, cx),
             stability: None,
             deprecation: None,
             inner: ImportItem(inner),

src/librustdoc/clean/types.rs

@@ -142,14 +142,15 @@ impl Item {
                 hir.span_with_body(hir.local_def_id_to_hir_id(local))
             },
         );
+        let hir_id = def_id.as_local().map(|local| cx.tcx.hir().local_def_id_to_hir_id(local));
 
         Item {
             def_id,
             inner,
             name: name.clean(cx),
             source: source.clean(cx),
             attrs: cx.tcx.get_attrs(def_id).clean(cx),
-            visibility: cx.tcx.visibility(def_id).clean(cx),
+            visibility: super::ty_visibility(cx.tcx.visibility(def_id), hir_id, cx),
             stability: cx.tcx.lookup_stability(def_id).cloned(),
             deprecation: cx.tcx.lookup_deprecation(def_id).clean(cx),
         }
@@ -1527,8 +1528,17 @@ impl From<hir::PrimTy> for PrimitiveType {
 
 #[derive(Clone, Debug)]
 pub enum Visibility {
+    /// `pub`
     Public,
+    /// Usually means private, but for enum variants it instead means 'always public'.
     Inherited,
+    /// `pub(self)`
+    ///
+    /// This has to be calculated ahead of time because `html` doesn't have access to a `tcx`.
+    /// Even if it did, `print_with_space` doesn't know the original item this was attached to
+    /// and so can't calculate whether the `DefPath` is `self` or not.
+    RestrictSelf,
+    /// `pub(in path)`
     Restricted(DefId, rustc_hir::definitions::DefPath),
 }
 

src/librustdoc/html/format.rs

@@ -1089,24 +1089,18 @@ impl Function<'_> {
 
 impl clean::Visibility {
     crate fn print_with_space(&self) -> impl fmt::Display + '_ {
-        use rustc_span::symbol::kw;
-
         display_fn(move |f| match *self {
             clean::Public => f.write_str("pub "),
             clean::Inherited => Ok(()),
+            clean::Visibility::RestrictSelf => f.write_str("pub(self) "),
             // If this is `pub(crate)`, `path` will be empty.
             clean::Visibility::Restricted(did, _) if did.index == CRATE_DEF_INDEX => {
                 write!(f, "pub(crate) ")
             }
             clean::Visibility::Restricted(did, ref path) => {
                 f.write_str("pub(")?;
                 debug!("path={:?}", path);
-                let first_name =
-                    path.data[0].data.get_opt_name().expect("modules are always named");
-                if path.data.len() != 1 || (first_name != kw::SelfLower && first_name != kw::Super)
-                {
-                    f.write_str("in ")?;
-                }
+
                 // modified from `resolved_path()` to work with `DefPathData`
                 let last_name = path.data.last().unwrap().data.get_opt_name().unwrap();
                 for seg in &path.data[..path.data.len() - 1] {