Rollup merge of #80368 - camelid:rustdoc-succinct-vis, r=jyn514

rustdoc: Render visibilities succinctly

Fixes #79139.

r? `@jyn514`

7 files changed, 136 insertions, 97 deletions

diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index 8b80f098baa..f4eb1924e6f 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -2325,18 +2325,19 @@ impl Clean<Item> for (&hir::MacroDef<'_>, Option<Symbol>) {
             )
         } else {
             let vis = item.vis.clean(cx);
+            let def_id = cx.tcx.hir().local_def_id(item.hir_id).to_def_id();
 
             if matchers.len() <= 1 {
                 format!(
                     "{}macro {}{} {{\n    ...\n}}",
-                    vis.print_with_space(cx.tcx),
+                    vis.print_with_space(cx.tcx, def_id),
                     name,
                     matchers.iter().map(|span| span.to_src(cx)).collect::<String>(),
                 )
             } else {
                 format!(
                     "{}macro {} {{\n{}}}",
-                    vis.print_with_space(cx.tcx),
+                    vis.print_with_space(cx.tcx, def_id),
                     name,
                     matchers
                         .iter()
diff --git a/src/librustdoc/clean/utils.rs b/src/librustdoc/clean/utils.rs
index a6c090c6576..d4482d6fa90 100644
--- a/src/librustdoc/clean/utils.rs
+++ b/src/librustdoc/clean/utils.rs
@@ -14,7 +14,7 @@ use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::{DefId, LOCAL_CRATE};
 use rustc_middle::mir::interpret::ConstValue;
 use rustc_middle::ty::subst::{GenericArgKind, SubstsRef};
-use rustc_middle::ty::{self, DefIdTree, Ty};
+use rustc_middle::ty::{self, DefIdTree, Ty, TyCtxt};
 use rustc_span::symbol::{kw, sym, Symbol};
 use std::mem;
 
@@ -623,3 +623,24 @@ where
     *cx.impl_trait_bounds.borrow_mut() = old_bounds;
     r
 }
+
+/// Find the nearest parent module of a [`DefId`].
+///
+/// **Panics if the item it belongs to [is fake][Item::is_fake].**
+crate fn find_nearest_parent_module(tcx: TyCtxt<'_>, def_id: DefId) -> Option<DefId> {
+    if def_id.is_top_level_module() {
+        // The crate root has no parent. Use it as the root instead.
+        Some(def_id)
+    } else {
+        let mut current = def_id;
+        // The immediate parent might not always be a module.
+        // Find the first parent which is.
+        while let Some(parent) = tcx.parent(current) {
+            if tcx.def_kind(parent) == DefKind::Mod {
+                return Some(parent);
+            }
+            current = parent;
+        }
+        None
+    }
+}
diff --git a/src/librustdoc/html/format.rs b/src/librustdoc/html/format.rs
index 7b0b219570b..9b2fb8582f5 100644
--- a/src/librustdoc/html/format.rs
+++ b/src/librustdoc/html/format.rs
@@ -15,7 +15,7 @@ use rustc_middle::ty::TyCtxt;
 use rustc_span::def_id::{DefId, CRATE_DEF_INDEX};
 use rustc_target::spec::abi::Abi;
 
-use crate::clean::{self, PrimitiveType};
+use crate::clean::{self, utils::find_nearest_parent_module, PrimitiveType};
 use crate::formats::cache::cache;
 use crate::formats::item_type::ItemType;
 use crate::html::escape::Escape;
@@ -1085,32 +1085,54 @@ impl Function<'_> {
 }
 
 impl clean::Visibility {
-    crate fn print_with_space<'tcx>(self, tcx: TyCtxt<'tcx>) -> impl fmt::Display + 'tcx {
+    crate fn print_with_space<'tcx>(
+        self,
+        tcx: TyCtxt<'tcx>,
+        item_did: DefId,
+    ) -> impl fmt::Display + 'tcx {
         use rustc_span::symbol::kw;
 
         display_fn(move |f| match self {
             clean::Public => f.write_str("pub "),
             clean::Inherited => Ok(()),
-            clean::Visibility::Restricted(did) if did.index == CRATE_DEF_INDEX => {
-                write!(f, "pub(crate) ")
-            }
-            clean::Visibility::Restricted(did) => {
-                f.write_str("pub(")?;
-                let path = tcx.def_path(did);
-                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)
+
+            clean::Visibility::Restricted(vis_did) => {
+                // FIXME(camelid): This may not work correctly if `item_did` is a module.
+                //                 However, rustdoc currently never displays a module's
+                //                 visibility, so it shouldn't matter.
+                let parent_module = find_nearest_parent_module(tcx, item_did);
+
+                if vis_did.index == CRATE_DEF_INDEX {
+                    write!(f, "pub(crate) ")
+                } else if parent_module == Some(vis_did) {
+                    // `pub(in foo)` where `foo` is the parent module
+                    // is the same as no visibility modifier
+                    Ok(())
+                } else if parent_module
+                    .map(|parent| find_nearest_parent_module(tcx, parent))
+                    .flatten()
+                    == Some(vis_did)
                 {
-                    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] {
-                    write!(f, "{}::", seg.data.get_opt_name().unwrap())?;
+                    write!(f, "pub(super) ")
+                } else {
+                    f.write_str("pub(")?;
+                    let path = tcx.def_path(vis_did);
+                    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] {
+                        write!(f, "{}::", seg.data.get_opt_name().unwrap())?;
+                    }
+                    let path = anchor(vis_did, &last_name.as_str()).to_string();
+                    write!(f, "{}) ", path)
                 }
-                let path = anchor(did, &last_name.as_str()).to_string();
-                write!(f, "{}) ", path)
             }
         })
     }
diff --git a/src/librustdoc/html/render/mod.rs b/src/librustdoc/html/render/mod.rs
index a83a3600383..c19262b72cf 100644
--- a/src/librustdoc/html/render/mod.rs
+++ b/src/librustdoc/html/render/mod.rs
@@ -2157,14 +2157,14 @@ fn item_module(w: &mut Buffer, cx: &Context<'_>, item: &clean::Item, items: &[cl
                     Some(ref src) => write!(
                         w,
                         "<tr><td><code>{}extern crate {} as {};",
-                        myitem.visibility.print_with_space(cx.tcx()),
+                        myitem.visibility.print_with_space(cx.tcx(), myitem.def_id),
                         anchor(myitem.def_id, &*src.as_str()),
                         name
                     ),
                     None => write!(
                         w,
                         "<tr><td><code>{}extern crate {};",
-                        myitem.visibility.print_with_space(cx.tcx()),
+                        myitem.visibility.print_with_space(cx.tcx(), myitem.def_id),
                         anchor(myitem.def_id, &*name.as_str())
                     ),
                 }
@@ -2175,7 +2175,7 @@ fn item_module(w: &mut Buffer, cx: &Context<'_>, item: &clean::Item, items: &[cl
                 write!(
                     w,
                     "<tr><td><code>{}{}</code></td></tr>",
-                    myitem.visibility.print_with_space(cx.tcx()),
+                    myitem.visibility.print_with_space(cx.tcx(), myitem.def_id),
                     import.print()
                 );
             }
@@ -2392,7 +2392,7 @@ fn item_constant(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, c: &clean::
     write!(
         w,
         "{vis}const {name}: {typ}",
-        vis = it.visibility.print_with_space(cx.tcx()),
+        vis = it.visibility.print_with_space(cx.tcx(), it.def_id),
         name = it.name.as_ref().unwrap(),
         typ = c.type_.print(),
     );
@@ -2426,7 +2426,7 @@ fn item_static(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, s: &clean::St
     write!(
         w,
         "{vis}static {mutability}{name}: {typ}</pre>",
-        vis = it.visibility.print_with_space(cx.tcx()),
+        vis = it.visibility.print_with_space(cx.tcx(), it.def_id),
         mutability = s.mutability.print_with_space(),
         name = it.name.as_ref().unwrap(),
         typ = s.type_.print()
@@ -2437,7 +2437,7 @@ fn item_static(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, s: &clean::St
 fn item_function(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, f: &clean::Function) {
     let header_len = format!(
         "{}{}{}{}{:#}fn {}{:#}",
-        it.visibility.print_with_space(cx.tcx()),
+        it.visibility.print_with_space(cx.tcx(), it.def_id),
         f.header.constness.print_with_space(),
         f.header.asyncness.print_with_space(),
         f.header.unsafety.print_with_space(),
@@ -2452,7 +2452,7 @@ fn item_function(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, f: &clean::
         w,
         "{vis}{constness}{asyncness}{unsafety}{abi}fn \
          {name}{generics}{decl}{spotlight}{where_clause}</pre>",
-        vis = it.visibility.print_with_space(cx.tcx()),
+        vis = it.visibility.print_with_space(cx.tcx(), it.def_id),
         constness = f.header.constness.print_with_space(),
         asyncness = f.header.asyncness.print_with_space(),
         unsafety = f.header.unsafety.print_with_space(),
@@ -2578,7 +2578,7 @@ fn item_trait(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, t: &clean::Tra
         write!(
             w,
             "{}{}{}trait {}{}{}",
-            it.visibility.print_with_space(cx.tcx()),
+            it.visibility.print_with_space(cx.tcx(), it.def_id),
             t.unsafety.print_with_space(),
             if t.is_auto { "auto " } else { "" },
             it.name.as_ref().unwrap(),
@@ -2896,7 +2896,7 @@ fn assoc_const(
         w,
         "{}{}const <a href=\"{}\" class=\"constant\"><b>{}</b></a>: {}",
         extra,
-        it.visibility.print_with_space(cx.tcx()),
+        it.visibility.print_with_space(cx.tcx(), it.def_id),
         naive_assoc_href(it, link),
         it.name.as_ref().unwrap(),
         ty.print()
@@ -3015,7 +3015,7 @@ fn render_assoc_item(
         };
         let mut header_len = format!(
             "{}{}{}{}{}{:#}fn {}{:#}",
-            meth.visibility.print_with_space(cx.tcx()),
+            meth.visibility.print_with_space(cx.tcx(), meth.def_id),
             header.constness.print_with_space(),
             header.asyncness.print_with_space(),
             header.unsafety.print_with_space(),
@@ -3037,7 +3037,7 @@ fn render_assoc_item(
             "{}{}{}{}{}{}{}fn <a href=\"{href}\" class=\"fnname\">{name}</a>\
              {generics}{decl}{spotlight}{where_clause}",
             if parent == ItemType::Trait { "    " } else { "" },
-            meth.visibility.print_with_space(cx.tcx()),
+            meth.visibility.print_with_space(cx.tcx(), meth.def_id),
             header.constness.print_with_space(),
             header.asyncness.print_with_space(),
             header.unsafety.print_with_space(),
@@ -3189,7 +3189,7 @@ fn item_enum(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, e: &clean::Enum
         write!(
             w,
             "{}enum {}{}{}",
-            it.visibility.print_with_space(cx.tcx()),
+            it.visibility.print_with_space(cx.tcx(), it.def_id),
             it.name.as_ref().unwrap(),
             e.generics.print(),
             WhereClause { gens: &e.generics, indent: 0, end_newline: true }
@@ -3365,7 +3365,7 @@ fn render_struct(
     write!(
         w,
         "{}{}{}",
-        it.visibility.print_with_space(cx.tcx()),
+        it.visibility.print_with_space(cx.tcx(), it.def_id),
         if structhead { "struct " } else { "" },
         it.name.as_ref().unwrap()
     );
@@ -3385,7 +3385,7 @@ fn render_struct(
                         w,
                         "\n{}    {}{}: {},",
                         tab,
-                        field.visibility.print_with_space(cx.tcx()),
+                        field.visibility.print_with_space(cx.tcx(), field.def_id),
                         field.name.as_ref().unwrap(),
                         ty.print()
                     );
@@ -3414,7 +3414,12 @@ fn render_struct(
                 match *field.kind {
                     clean::StrippedItem(box clean::StructFieldItem(..)) => write!(w, "_"),
                     clean::StructFieldItem(ref ty) => {
-                        write!(w, "{}{}", field.visibility.print_with_space(cx.tcx()), ty.print())
+                        write!(
+                            w,
+                            "{}{}",
+                            field.visibility.print_with_space(cx.tcx(), field.def_id),
+                            ty.print()
+                        )
                     }
                     _ => unreachable!(),
                 }
@@ -3447,7 +3452,7 @@ fn render_union(
     write!(
         w,
         "{}{}{}",
-        it.visibility.print_with_space(cx.tcx()),
+        it.visibility.print_with_space(cx.tcx(), it.def_id),
         if structhead { "union " } else { "" },
         it.name.as_ref().unwrap()
     );
@@ -3462,7 +3467,7 @@ fn render_union(
             write!(
                 w,
                 "    {}{}: {},\n{}",
-                field.visibility.print_with_space(cx.tcx()),
+                field.visibility.print_with_space(cx.tcx(), field.def_id),
                 field.name.as_ref().unwrap(),
                 ty.print(),
                 tab
@@ -4101,7 +4106,7 @@ fn item_foreign_type(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, cache:
     write!(
         w,
         "    {}type {};\n}}</pre>",
-        it.visibility.print_with_space(cx.tcx()),
+        it.visibility.print_with_space(cx.tcx(), it.def_id),
         it.name.as_ref().unwrap(),
     );
 
diff --git a/src/librustdoc/passes/collect_intra_doc_links.rs b/src/librustdoc/passes/collect_intra_doc_links.rs
index 63cb02af3bc..9f15038a353 100644
--- a/src/librustdoc/passes/collect_intra_doc_links.rs
+++ b/src/librustdoc/passes/collect_intra_doc_links.rs
@@ -31,7 +31,7 @@ use std::convert::{TryFrom, TryInto};
 use std::mem;
 use std::ops::Range;
 
-use crate::clean::{self, Crate, 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;
@@ -830,31 +830,9 @@ impl<'a, 'tcx> DocFolder for LinkCollector<'a, 'tcx> {
         use rustc_middle::ty::DefIdTree;
 
         let parent_node = if item.is_fake() {
-            // FIXME: is this correct?
             None
-        // If we're documenting the crate root itself, it has no parent. Use the root instead.
-        } else if item.def_id.is_top_level_module() {
-            Some(item.def_id)
         } else {
-            let mut current = item.def_id;
-            // The immediate parent might not always be a module.
-            // Find the first parent which is.
-            loop {
-                if let Some(parent) = self.cx.tcx.parent(current) {
-                    if self.cx.tcx.def_kind(parent) == DefKind::Mod {
-                        break Some(parent);
-                    }
-                    current = parent;
-                } else {
-                    debug!(
-                        "{:?} has no parent (kind={:?}, original was {:?})",
-                        current,
-                        self.cx.tcx.def_kind(current),
-                        item.def_id
-                    );
-                    break None;
-                }
-            }
+            find_nearest_parent_module(self.cx.tcx, item.def_id)
         };
 
         if parent_node.is_some() {
diff --git a/src/test/rustdoc/pub-restricted.rs b/src/test/rustdoc/pub-restricted.rs
deleted file mode 100644
index 6720d848ac3..00000000000
--- a/src/test/rustdoc/pub-restricted.rs
+++ /dev/null
@@ -1,32 +0,0 @@
-// compile-flags: --document-private-items
-
-#![feature(crate_visibility_modifier)]
-
-#![crate_name = "foo"]
-
-// @has 'foo/struct.FooPublic.html' '//pre' 'pub struct FooPublic'
-pub struct FooPublic;
-// @has 'foo/struct.FooJustCrate.html' '//pre' 'pub(crate) struct FooJustCrate'
-crate struct FooJustCrate;
-// @has 'foo/struct.FooPubCrate.html' '//pre' 'pub(crate) struct FooPubCrate'
-pub(crate) struct FooPubCrate;
-// @has 'foo/struct.FooSelf.html' '//pre' 'pub(crate) struct FooSelf'
-pub(self) struct FooSelf;
-// @has 'foo/struct.FooInSelf.html' '//pre' 'pub(crate) struct FooInSelf'
-pub(in self) struct FooInSelf;
-mod a {
-    // @has 'foo/a/struct.FooSuper.html' '//pre' 'pub(crate) struct FooSuper'
-    pub(super) struct FooSuper;
-    // @has 'foo/a/struct.FooInSuper.html' '//pre' 'pub(crate) struct FooInSuper'
-    pub(in super) struct FooInSuper;
-    // @has 'foo/a/struct.FooInA.html' '//pre' 'pub(in a) struct FooInA'
-    pub(in a) struct FooInA;
-    mod b {
-        // @has 'foo/a/b/struct.FooInSelfSuperB.html' '//pre' 'pub(in a::b) struct FooInSelfSuperB'
-        pub(in a::b) struct FooInSelfSuperB;
-        // @has 'foo/a/b/struct.FooInSuperSuper.html' '//pre' 'pub(crate) struct FooInSuperSuper'
-        pub(in super::super) struct FooInSuperSuper;
-        // @has 'foo/a/b/struct.FooInAB.html' '//pre' 'pub(in a::b) struct FooInAB'
-        pub(in a::b) struct FooInAB;
-    }
-}
diff --git a/src/test/rustdoc/visibility.rs b/src/test/rustdoc/visibility.rs
new file mode 100644
index 00000000000..59427693c5a
--- /dev/null
+++ b/src/test/rustdoc/visibility.rs
@@ -0,0 +1,44 @@
+// compile-flags: --document-private-items
+
+#![feature(crate_visibility_modifier)]
+
+#![crate_name = "foo"]
+
+// @has 'foo/struct.FooPublic.html' '//pre' 'pub struct FooPublic'
+pub struct FooPublic;
+// @has 'foo/struct.FooJustCrate.html' '//pre' 'pub(crate) struct FooJustCrate'
+crate struct FooJustCrate;
+// @has 'foo/struct.FooPubCrate.html' '//pre' 'pub(crate) struct FooPubCrate'
+pub(crate) struct FooPubCrate;
+// @has 'foo/struct.FooSelf.html' '//pre' 'pub(crate) struct FooSelf'
+pub(self) struct FooSelf;
+// @has 'foo/struct.FooInSelf.html' '//pre' 'pub(crate) struct FooInSelf'
+pub(in self) struct FooInSelf;
+// @has 'foo/struct.FooPriv.html' '//pre' 'pub(crate) struct FooPriv'
+struct FooPriv;
+
+mod a {
+    // @has 'foo/a/struct.FooASuper.html' '//pre' 'pub(crate) struct FooASuper'
+    pub(super) struct FooASuper;
+    // @has 'foo/a/struct.FooAInSuper.html' '//pre' 'pub(crate) struct FooAInSuper'
+    pub(in super) struct FooAInSuper;
+    // @has 'foo/a/struct.FooAInA.html' '//pre' 'struct FooAInA'
+    // @!has 'foo/a/struct.FooAInA.html' '//pre' 'pub'
+    pub(in a) struct FooAInA;
+    // @has 'foo/a/struct.FooAPriv.html' '//pre' 'struct FooAPriv'
+    // @!has 'foo/a/struct.FooAPriv.html' '//pre' 'pub'
+    struct FooAPriv;
+
+    mod b {
+        // @has 'foo/a/b/struct.FooBSuper.html' '//pre' 'pub(super) struct FooBSuper'
+        pub(super) struct FooBSuper;
+        // @has 'foo/a/b/struct.FooBInSuperSuper.html' '//pre' 'pub(crate) struct FooBInSuperSuper'
+        pub(in super::super) struct FooBInSuperSuper;
+        // @has 'foo/a/b/struct.FooBInAB.html' '//pre' 'struct FooBInAB'
+        // @!has 'foo/a/b/struct.FooBInAB.html' '//pre' 'pub'
+        pub(in a::b) struct FooBInAB;
+        // @has 'foo/a/b/struct.FooBPriv.html' '//pre' 'struct FooBPriv'
+        // @!has 'foo/a/b/struct.FooBPriv.html' '//pre' 'pub'
+        struct FooBPriv;
+    }
+}