Generate sidebar elements for the "All items" page

src/librustdoc/html/render/context.rs

@@ -17,8 +17,8 @@ use super::print_item::{full_path, item_path, print_item};
 use super::search_index::build_index;
 use super::write_shared::write_shared;
 use super::{
-    collect_spans_and_sources, print_sidebar, scrape_examples_help, AllTypes, LinkFromSrc, NameDoc,
-    StylePath, BASIC_KEYWORDS,
+    collect_spans_and_sources, print_sidebar, scrape_examples_help, sidebar_module_like, AllTypes,
+    LinkFromSrc, NameDoc, StylePath, BASIC_KEYWORDS,
 };
 
 use crate::clean::{self, types::ExternalLocation, ExternalCrate};
@@ -597,16 +597,24 @@ impl<'tcx> FormatRenderer<'tcx> for Context<'tcx> {
             keywords: BASIC_KEYWORDS,
             resource_suffix: &shared.resource_suffix,
         };
-        let sidebar = if shared.cache.crate_version.is_some() {
-            format!("<h2 class=\"location\">Crate {}</h2>", crate_name)
-        } else {
-            String::new()
-        };
         let all = shared.all.replace(AllTypes::new());
+        let mut sidebar = Buffer::html();
+        if shared.cache.crate_version.is_some() {
+            write!(sidebar, "<h2 class=\"location\">Crate {}</h2>", crate_name)
+        };
+
+        let mut items = Buffer::html();
+        sidebar_module_like(&mut items, all.item_sections());
+        if !items.is_empty() {
+            sidebar.push_str("<div class=\"sidebar-elems\">");
+            sidebar.push_buffer(items);
+            sidebar.push_str("</div>");
+        }
+
         let v = layout::render(
             &shared.layout,
             &page,
-            sidebar,
+            sidebar.into_inner(),
             |buf: &mut Buffer| all.print(buf),
             &shared.style_files,
         );

src/librustdoc/html/render/mod.rs

@@ -290,9 +290,56 @@ impl AllTypes {
             };
         }
     }
-}
 
-impl AllTypes {
+    fn item_sections(&self) -> FxHashSet<ItemSection> {
+        let mut sections = FxHashSet::default();
+
+        if !self.structs.is_empty() {
+            sections.insert(ItemSection::Structs);
+        }
+        if !self.enums.is_empty() {
+            sections.insert(ItemSection::Enums);
+        }
+        if !self.unions.is_empty() {
+            sections.insert(ItemSection::Unions);
+        }
+        if !self.primitives.is_empty() {
+            sections.insert(ItemSection::PrimitiveTypes);
+        }
+        if !self.traits.is_empty() {
+            sections.insert(ItemSection::Traits);
+        }
+        if !self.macros.is_empty() {
+            sections.insert(ItemSection::Macros);
+        }
+        if !self.functions.is_empty() {
+            sections.insert(ItemSection::Functions);
+        }
+        if !self.typedefs.is_empty() {
+            sections.insert(ItemSection::TypeDefinitions);
+        }
+        if !self.opaque_tys.is_empty() {
+            sections.insert(ItemSection::OpaqueTypes);
+        }
+        if !self.statics.is_empty() {
+            sections.insert(ItemSection::Statics);
+        }
+        if !self.constants.is_empty() {
+            sections.insert(ItemSection::Constants);
+        }
+        if !self.attributes.is_empty() {
+            sections.insert(ItemSection::AttributeMacros);
+        }
+        if !self.derives.is_empty() {
+            sections.insert(ItemSection::DeriveMacros);
+        }
+        if !self.trait_aliases.is_empty() {
+            sections.insert(ItemSection::TraitAliases);
+        }
+
+        sections
+    }
+
     fn print(self, f: &mut Buffer) {
         fn print_entries(f: &mut Buffer, e: &FxHashSet<ItemEntry>, title: &str) {
             if !e.is_empty() {
@@ -2468,7 +2515,7 @@ fn sidebar_enum(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, e: &clean:
 }
 
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
-enum ItemSection {
+pub(crate) enum ItemSection {
     Reexports,
     PrimitiveTypes,
     Modules,
@@ -2620,25 +2667,11 @@ fn item_ty_to_section(ty: ItemType) -> ItemSection {
     }
 }
 
-fn sidebar_module(buf: &mut Buffer, items: &[clean::Item]) {
+pub(crate) fn sidebar_module_like(buf: &mut Buffer, item_sections_in_use: FxHashSet<ItemSection>) {
     use std::fmt::Write as _;
 
     let mut sidebar = String::new();
 
-    let item_sections_in_use: FxHashSet<_> = items
-        .iter()
-        .filter(|it| {
-            !it.is_stripped()
-                && it
-                    .name
-                    .or_else(|| {
-                        if let clean::ImportItem(ref i) = *it.kind &&
-                            let clean::ImportKind::Simple(s) = i.kind { Some(s) } else { None }
-                    })
-                    .is_some()
-        })
-        .map(|it| item_ty_to_section(it.type_()))
-        .collect();
     for &sec in ItemSection::ALL.iter().filter(|sec| item_sections_in_use.contains(sec)) {
         let _ = write!(sidebar, "<li><a href=\"#{}\">{}</a></li>", sec.id(), sec.name());
     }
@@ -2656,6 +2689,25 @@ fn sidebar_module(buf: &mut Buffer, items: &[clean::Item]) {
     }
 }
 
+fn sidebar_module(buf: &mut Buffer, items: &[clean::Item]) {
+    let item_sections_in_use: FxHashSet<_> = items
+        .iter()
+        .filter(|it| {
+            !it.is_stripped()
+                && it
+                    .name
+                    .or_else(|| {
+                        if let clean::ImportItem(ref i) = *it.kind &&
+                            let clean::ImportKind::Simple(s) = i.kind { Some(s) } else { None }
+                    })
+                    .is_some()
+        })
+        .map(|it| item_ty_to_section(it.type_()))
+        .collect();
+
+    sidebar_module_like(buf, item_sections_in_use);
+}
+
 fn sidebar_foreign_type(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item) {
     let mut sidebar = Buffer::new();
     sidebar_assoc_items(cx, &mut sidebar, it);