Refactor sidebar printing code

src/librustdoc/html/render/mod.rs

@@ -2409,78 +2409,170 @@ fn sidebar_enum(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, e: &clean:
     }
 }
 
-fn item_ty_to_strs(ty: ItemType) -> (&'static str, &'static str) {
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
+enum ItemSection {
+    Reexports,
+    PrimitiveTypes,
+    Modules,
+    Macros,
+    Structs,
+    Enums,
+    Constants,
+    Statics,
+    Traits,
+    Functions,
+    TypeDefinitions,
+    Unions,
+    Implementations,
+    TypeMethods,
+    Methods,
+    StructFields,
+    Variants,
+    AssociatedTypes,
+    AssociatedConstants,
+    ForeignTypes,
+    Keywords,
+    OpaqueTypes,
+    AttributeMacros,
+    DeriveMacros,
+    TraitAliases,
+}
+
+impl ItemSection {
+    const ALL: &'static [Self] = {
+        use ItemSection::*;
+        // NOTE: The order here affects the order in the UI.
+        &[
+            Reexports,
+            PrimitiveTypes,
+            Modules,
+            Macros,
+            Structs,
+            Enums,
+            Constants,
+            Statics,
+            Traits,
+            Functions,
+            TypeDefinitions,
+            Unions,
+            Implementations,
+            TypeMethods,
+            Methods,
+            StructFields,
+            Variants,
+            AssociatedTypes,
+            AssociatedConstants,
+            ForeignTypes,
+            Keywords,
+            OpaqueTypes,
+            AttributeMacros,
+            DeriveMacros,
+            TraitAliases,
+        ]
+    };
+
+    fn id(self) -> &'static str {
+        match self {
+            Self::Reexports => "reexports",
+            Self::Modules => "modules",
+            Self::Structs => "structs",
+            Self::Unions => "unions",
+            Self::Enums => "enums",
+            Self::Functions => "functions",
+            Self::TypeDefinitions => "types",
+            Self::Statics => "statics",
+            Self::Constants => "constants",
+            Self::Traits => "traits",
+            Self::Implementations => "impls",
+            Self::TypeMethods => "tymethods",
+            Self::Methods => "methods",
+            Self::StructFields => "fields",
+            Self::Variants => "variants",
+            Self::Macros => "macros",
+            Self::PrimitiveTypes => "primitives",
+            Self::AssociatedTypes => "associated-types",
+            Self::AssociatedConstants => "associated-consts",
+            Self::ForeignTypes => "foreign-types",
+            Self::Keywords => "keywords",
+            Self::OpaqueTypes => "opaque-types",
+            Self::AttributeMacros => "attributes",
+            Self::DeriveMacros => "derives",
+            Self::TraitAliases => "trait-aliases",
+        }
+    }
+
+    fn name(self) -> &'static str {
+        match self {
+            Self::Reexports => "Re-exports",
+            Self::Modules => "Modules",
+            Self::Structs => "Structs",
+            Self::Unions => "Unions",
+            Self::Enums => "Enums",
+            Self::Functions => "Functions",
+            Self::TypeDefinitions => "Type Definitions",
+            Self::Statics => "Statics",
+            Self::Constants => "Constants",
+            Self::Traits => "Traits",
+            Self::Implementations => "Implementations",
+            Self::TypeMethods => "Type Methods",
+            Self::Methods => "Methods",
+            Self::StructFields => "Struct Fields",
+            Self::Variants => "Variants",
+            Self::Macros => "Macros",
+            Self::PrimitiveTypes => "Primitive Types",
+            Self::AssociatedTypes => "Associated Types",
+            Self::AssociatedConstants => "Associated Constants",
+            Self::ForeignTypes => "Foreign Types",
+            Self::Keywords => "Keywords",
+            Self::OpaqueTypes => "Opaque Types",
+            Self::AttributeMacros => "Attribute Macros",
+            Self::DeriveMacros => "Derive Macros",
+            Self::TraitAliases => "Trait Aliases",
+        }
+    }
+}
+
+fn item_ty_to_section(ty: ItemType) -> ItemSection {
     match ty {
-        ItemType::ExternCrate | ItemType::Import => ("reexports", "Re-exports"),
-        ItemType::Module => ("modules", "Modules"),
-        ItemType::Struct => ("structs", "Structs"),
-        ItemType::Union => ("unions", "Unions"),
-        ItemType::Enum => ("enums", "Enums"),
-        ItemType::Function => ("functions", "Functions"),
-        ItemType::Typedef => ("types", "Type Definitions"),
-        ItemType::Static => ("statics", "Statics"),
-        ItemType::Constant => ("constants", "Constants"),
-        ItemType::Trait => ("traits", "Traits"),
-        ItemType::Impl => ("impls", "Implementations"),
-        ItemType::TyMethod => ("tymethods", "Type Methods"),
-        ItemType::Method => ("methods", "Methods"),
-        ItemType::StructField => ("fields", "Struct Fields"),
-        ItemType::Variant => ("variants", "Variants"),
-        ItemType::Macro => ("macros", "Macros"),
-        ItemType::Primitive => ("primitives", "Primitive Types"),
-        ItemType::AssocType => ("associated-types", "Associated Types"),
-        ItemType::AssocConst => ("associated-consts", "Associated Constants"),
-        ItemType::ForeignType => ("foreign-types", "Foreign Types"),
-        ItemType::Keyword => ("keywords", "Keywords"),
-        ItemType::OpaqueTy => ("opaque-types", "Opaque Types"),
-        ItemType::ProcAttribute => ("attributes", "Attribute Macros"),
-        ItemType::ProcDerive => ("derives", "Derive Macros"),
-        ItemType::TraitAlias => ("trait-aliases", "Trait aliases"),
+        ItemType::ExternCrate | ItemType::Import => ItemSection::Reexports,
+        ItemType::Module => ItemSection::Modules,
+        ItemType::Struct => ItemSection::Structs,
+        ItemType::Union => ItemSection::Unions,
+        ItemType::Enum => ItemSection::Enums,
+        ItemType::Function => ItemSection::Functions,
+        ItemType::Typedef => ItemSection::TypeDefinitions,
+        ItemType::Static => ItemSection::Statics,
+        ItemType::Constant => ItemSection::Constants,
+        ItemType::Trait => ItemSection::Traits,
+        ItemType::Impl => ItemSection::Implementations,
+        ItemType::TyMethod => ItemSection::TypeMethods,
+        ItemType::Method => ItemSection::Methods,
+        ItemType::StructField => ItemSection::StructFields,
+        ItemType::Variant => ItemSection::Variants,
+        ItemType::Macro => ItemSection::Macros,
+        ItemType::Primitive => ItemSection::PrimitiveTypes,
+        ItemType::AssocType => ItemSection::AssociatedTypes,
+        ItemType::AssocConst => ItemSection::AssociatedConstants,
+        ItemType::ForeignType => ItemSection::ForeignTypes,
+        ItemType::Keyword => ItemSection::Keywords,
+        ItemType::OpaqueTy => ItemSection::OpaqueTypes,
+        ItemType::ProcAttribute => ItemSection::AttributeMacros,
+        ItemType::ProcDerive => ItemSection::DeriveMacros,
+        ItemType::TraitAlias => ItemSection::TraitAliases,
         ItemType::Generic => unreachable!(),
     }
 }
 
 fn sidebar_module(buf: &mut Buffer, items: &[clean::Item]) {
     let mut sidebar = String::new();
 
-    // Re-exports are handled a bit differently because they can be extern crates or imports.
-    if items.iter().any(|it| {
-        it.name.is_some()
-            && (it.type_() == ItemType::ExternCrate
-                || (it.type_() == ItemType::Import && !it.is_stripped()))
-    }) {
-        let (id, name) = item_ty_to_strs(ItemType::Import);
-        sidebar.push_str(&format!("<li><a href=\"#{}\">{}</a></li>", id, name));
-    }
-
-    // ordering taken from item_module, reorder, where it prioritized elements in a certain order
-    // to print its headings
-    for &myty in &[
-        ItemType::Primitive,
-        ItemType::Module,
-        ItemType::Macro,
-        ItemType::Struct,
-        ItemType::Enum,
-        ItemType::Constant,
-        ItemType::Static,
-        ItemType::Trait,
-        ItemType::Function,
-        ItemType::Typedef,
-        ItemType::Union,
-        ItemType::Impl,
-        ItemType::TyMethod,
-        ItemType::Method,
-        ItemType::StructField,
-        ItemType::Variant,
-        ItemType::AssocType,
-        ItemType::AssocConst,
-        ItemType::ForeignType,
-        ItemType::Keyword,
-    ] {
-        if items.iter().any(|it| !it.is_stripped() && it.type_() == myty && it.name.is_some()) {
-            let (id, name) = item_ty_to_strs(myty);
-            sidebar.push_str(&format!("<li><a href=\"#{}\">{}</a></li>", id, name));
-        }
+    let item_sections_in_use: FxHashSet<_> = items
+        .iter()
+        .filter(|it| !it.is_stripped() && it.name.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)) {
+        sidebar.push_str(&format!("<li><a href=\"#{}\">{}</a></li>", sec.id(), sec.name()));
     }
 
     if !sidebar.is_empty() {

src/librustdoc/html/render/print_item.rs

@@ -16,10 +16,10 @@ use rustc_span::symbol::{kw, sym, Symbol};
 use rustc_target::abi::{Layout, Primitive, TagEncoding, Variants};
 
 use super::{
-    collect_paths_for_type, document, ensure_trailing_slash, item_ty_to_strs, notable_traits_decl,
-    render_assoc_item, render_assoc_items, render_attributes_in_code, render_attributes_in_pre,
-    render_impl, render_stability_since_raw, write_srclink, AssocItemLink, Context,
-    ImplRenderingParameters,
+    collect_paths_for_type, document, ensure_trailing_slash, item_ty_to_section,
+    notable_traits_decl, render_assoc_item, render_assoc_items, render_attributes_in_code,
+    render_attributes_in_pre, render_impl, render_stability_since_raw, write_srclink,
+    AssocItemLink, Context, ImplRenderingParameters,
 };
 use crate::clean;
 use crate::formats::item_type::ItemType;
@@ -222,7 +222,9 @@ fn item_module(w: &mut Buffer, cx: &Context<'_>, item: &clean::Item, items: &[cl
     ) -> Ordering {
         let ty1 = i1.type_();
         let ty2 = i2.type_();
-        if ty1 != ty2 {
+        if item_ty_to_section(ty1) != item_ty_to_section(ty2)
+            || (ty1 != ty2 && (ty1 == ItemType::ExternCrate || ty2 == ItemType::ExternCrate))
+        {
             return (reorder(ty1), idx1).cmp(&(reorder(ty2), idx2));
         }
         let s1 = i1.stability(tcx).as_ref().map(|s| s.level);
@@ -271,32 +273,28 @@ fn item_module(w: &mut Buffer, cx: &Context<'_>, item: &clean::Item, items: &[cl
     });
 
     debug!("{:?}", indices);
-    let mut curty = None;
+    let mut last_section = None;
 
     for &idx in &indices {
         let myitem = &items[idx];
         if myitem.is_stripped() {
             continue;
         }
 
-        let myty = Some(myitem.type_());
-        if curty == Some(ItemType::ExternCrate) && myty == Some(ItemType::Import) {
-            // Put `extern crate` and `use` re-exports in the same section.
-            curty = myty;
-        } else if myty != curty {
-            if curty.is_some() {
+        let my_section = item_ty_to_section(myitem.type_());
+        if Some(my_section) != last_section {
+            if last_section.is_some() {
                 w.write_str(ITEM_TABLE_CLOSE);
             }
-            curty = myty;
-            let (short, name) = item_ty_to_strs(myty.unwrap());
+            last_section = Some(my_section);
             write!(
                 w,
                 "<h2 id=\"{id}\" class=\"small-section-header\">\
                     <a href=\"#{id}\">{name}</a>\
                  </h2>\n{}",
                 ITEM_TABLE_OPEN,
-                id = cx.derive_id(short.to_owned()),
-                name = name
+                id = cx.derive_id(my_section.id().to_owned()),
+                name = my_section.name(),
             );
         }
 
@@ -408,7 +406,7 @@ fn item_module(w: &mut Buffer, cx: &Context<'_>, item: &clean::Item, items: &[cl
         }
     }
 
-    if curty.is_some() {
+    if last_section.is_some() {
         w.write_str(ITEM_TABLE_CLOSE);
     }
 }

src/test/rustdoc/trait_alias.rs

@@ -8,7 +8,7 @@ use std::fmt::Debug;
 // @has foo/all.html '//a[@href="traitalias.Alias2.html"]' 'Alias2'
 // @has foo/all.html '//a[@href="traitalias.Foo.html"]' 'Foo'
 
-// @has foo/index.html '//h2[@id="trait-aliases"]' 'Trait aliases'
+// @has foo/index.html '//h2[@id="trait-aliases"]' 'Trait Aliases'
 // @has foo/index.html '//a[@class="traitalias"]' 'CopyAlias'
 // @has foo/index.html '//a[@class="traitalias"]' 'Alias2'
 // @has foo/index.html '//a[@class="traitalias"]' 'Foo'