Rollup merge of #108784 - clubby789:askama-sidebar, r=jsha,GuillaumeGomez

rustdoc: Migrate sidebar rendering to Askama

cc #108757

Renders the sidebar for documentation using an Askama template

src/librustdoc/html/render/context.rs

@@ -17,10 +17,11 @@ 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, sidebar_module_like, AllTypes,
+    collect_spans_and_sources, scrape_examples_help,
-    LinkFromSrc, StylePath,
+    sidebar::print_sidebar,
+    sidebar::{sidebar_module_like, Sidebar},
+    AllTypes, LinkFromSrc, StylePath,
 };
-
 use crate::clean::{self, types::ExternalLocation, ExternalCrate};
 use crate::config::{ModuleSorting, RenderOptions};
 use crate::docfs::{DocFS, PathError};
@@ -35,6 +36,7 @@ use crate::html::url_parts_builder::UrlPartsBuilder;
 use crate::html::{layout, sources, static_files};
 use crate::scrape_examples::AllCallLocations;
 use crate::try_err;
+use askama::Template;
 
 /// Major driving force in all rustdoc rendering. This contains information
 /// about where in the tree-like hierarchy rendering is occurring and controls
@@ -600,15 +602,18 @@ impl<'tcx> FormatRenderer<'tcx> for Context<'tcx> {
         };
         let all = shared.all.replace(AllTypes::new());
         let mut sidebar = Buffer::html();
-        write!(sidebar, "<h2 class=\"location\"><a href=\"#\">Crate {}</a></h2>", crate_name);
 
-        let mut items = Buffer::html();
+        let blocks = sidebar_module_like(all.item_sections());
-        sidebar_module_like(&mut items, all.item_sections());
+        let bar = Sidebar {
-        if !items.is_empty() {
+            title_prefix: "Crate ",
-            sidebar.push_str("<div class=\"sidebar-elems\">");
+            title: crate_name.as_str(),
-            sidebar.push_buffer(items);
+            is_crate: false,
-            sidebar.push_str("</div>");
+            version: "",
-        }
+            blocks: vec![blocks],
+            path: String::new(),
+        };
+
+        bar.render_into(&mut sidebar).unwrap();
 
         let v = layout::render(
             &shared.layout,

src/librustdoc/html/render/mod.rs

@@ -30,6 +30,7 @@ mod tests;
 
 mod context;
 mod print_item;
+mod sidebar;
 mod span_map;
 mod write_shared;
 
@@ -50,11 +51,9 @@ use askama::Template;
 use rustc_ast_pretty::pprust;
 use rustc_attr::{ConstStability, Deprecation, StabilityLevel};
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
-use rustc_hir::def::CtorKind;
 use rustc_hir::def_id::{DefId, DefIdSet};
 use rustc_hir::Mutability;
 use rustc_middle::middle::stability;
-use rustc_middle::ty;
 use rustc_middle::ty::TyCtxt;
 use rustc_span::{
     symbol::{sym, Symbol},
@@ -1881,154 +1880,6 @@ pub(crate) fn render_impl_summary(
     w.write_str("</section>");
 }
 
-fn print_sidebar(cx: &Context<'_>, it: &clean::Item, buffer: &mut Buffer) {
-    if it.is_struct()
-        || it.is_trait()
-        || it.is_primitive()
-        || it.is_union()
-        || it.is_enum()
-        || it.is_mod()
-        || it.is_typedef()
-    {
-        write!(
-            buffer,
-            "<h2 class=\"location\"><a href=\"#\">{}{}</a></h2>",
-            match *it.kind {
-                clean::ModuleItem(..) =>
-                    if it.is_crate() {
-                        "Crate "
-                    } else {
-                        "Module "
-                    },
-                _ => "",
-            },
-            it.name.as_ref().unwrap()
-        );
-    }
-
-    buffer.write_str("<div class=\"sidebar-elems\">");
-    if it.is_crate() {
-        write!(buffer, "<ul class=\"block\">");
-        if let Some(ref version) = cx.cache().crate_version {
-            write!(buffer, "<li class=\"version\">Version {}</li>", Escape(version));
-        }
-        write!(buffer, "<li><a id=\"all-types\" href=\"all.html\">All Items</a></li>");
-        buffer.write_str("</ul>");
-    }
-
-    match *it.kind {
-        clean::StructItem(ref s) => sidebar_struct(cx, buffer, it, s),
-        clean::TraitItem(ref t) => sidebar_trait(cx, buffer, it, t),
-        clean::PrimitiveItem(_) => sidebar_primitive(cx, buffer, it),
-        clean::UnionItem(ref u) => sidebar_union(cx, buffer, it, u),
-        clean::EnumItem(ref e) => sidebar_enum(cx, buffer, it, e),
-        clean::TypedefItem(_) => sidebar_typedef(cx, buffer, it),
-        clean::ModuleItem(ref m) => sidebar_module(buffer, &m.items),
-        clean::ForeignTypeItem => sidebar_foreign_type(cx, buffer, it),
-        _ => {}
-    }
-
-    // The sidebar is designed to display sibling functions, modules and
-    // other miscellaneous information. since there are lots of sibling
-    // items (and that causes quadratic growth in large modules),
-    // we refactor common parts into a shared JavaScript file per module.
-    // still, we don't move everything into JS because we want to preserve
-    // as much HTML as possible in order to allow non-JS-enabled browsers
-    // to navigate the documentation (though slightly inefficiently).
-
-    if !it.is_mod() {
-        let path: String = cx.current.iter().map(|s| s.as_str()).intersperse("::").collect();
-
-        write!(buffer, "<h2><a href=\"index.html\">In {}</a></h2>", path);
-    }
-
-    // Closes sidebar-elems div.
-    buffer.write_str("</div>");
-}
-
-fn get_next_url(used_links: &mut FxHashSet<String>, url: String) -> String {
-    if used_links.insert(url.clone()) {
-        return url;
-    }
-    let mut add = 1;
-    while !used_links.insert(format!("{}-{}", url, add)) {
-        add += 1;
-    }
-    format!("{}-{}", url, add)
-}
-
-struct SidebarLink {
-    name: Symbol,
-    url: String,
-}
-
-impl fmt::Display for SidebarLink {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "<a href=\"#{}\">{}</a>", self.url, self.name)
-    }
-}
-
-impl PartialEq for SidebarLink {
-    fn eq(&self, other: &Self) -> bool {
-        self.url == other.url
-    }
-}
-
-impl Eq for SidebarLink {}
-
-impl PartialOrd for SidebarLink {
-    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
-        Some(self.cmp(other))
-    }
-}
-
-impl Ord for SidebarLink {
-    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
-        self.url.cmp(&other.url)
-    }
-}
-
-fn get_methods(
-    i: &clean::Impl,
-    for_deref: bool,
-    used_links: &mut FxHashSet<String>,
-    deref_mut: bool,
-    tcx: TyCtxt<'_>,
-) -> Vec<SidebarLink> {
-    i.items
-        .iter()
-        .filter_map(|item| match item.name {
-            Some(name) if !name.is_empty() && item.is_method() => {
-                if !for_deref || should_render_item(item, deref_mut, tcx) {
-                    Some(SidebarLink {
-                        name,
-                        url: get_next_url(used_links, format!("{}.{}", ItemType::Method, name)),
-                    })
-                } else {
-                    None
-                }
-            }
-            _ => None,
-        })
-        .collect::<Vec<_>>()
-}
-
-fn get_associated_constants(
-    i: &clean::Impl,
-    used_links: &mut FxHashSet<String>,
-) -> Vec<SidebarLink> {
-    i.items
-        .iter()
-        .filter_map(|item| match item.name {
-            Some(name) if !name.is_empty() && item.is_associated_const() => Some(SidebarLink {
-                name,
-                url: get_next_url(used_links, format!("{}.{}", ItemType::AssocConst, name)),
-            }),
-            _ => None,
-        })
-        .collect::<Vec<_>>()
-}
-
 pub(crate) fn small_url_encode(s: String) -> String {
     // These characters don't need to be escaped in a URI.
     // See https://url.spec.whatwg.org/#query-percent-encode-set
@@ -2094,232 +1945,6 @@ pub(crate) fn small_url_encode(s: String) -> String {
     }
 }
 
-pub(crate) fn sidebar_render_assoc_items(
-    cx: &Context<'_>,
-    out: &mut Buffer,
-    id_map: &mut IdMap,
-    concrete: Vec<&Impl>,
-    synthetic: Vec<&Impl>,
-    blanket_impl: Vec<&Impl>,
-) {
-    let format_impls = |impls: Vec<&Impl>, id_map: &mut IdMap| {
-        let mut links = FxHashSet::default();
-
-        let mut ret = impls
-            .iter()
-            .filter_map(|it| {
-                let trait_ = it.inner_impl().trait_.as_ref()?;
-                let encoded =
-                    id_map.derive(get_id_for_impl(&it.inner_impl().for_, Some(trait_), cx));
-
-                let i_display = format!("{:#}", trait_.print(cx));
-                let out = Escape(&i_display);
-                let prefix = match it.inner_impl().polarity {
-                    ty::ImplPolarity::Positive | ty::ImplPolarity::Reservation => "",
-                    ty::ImplPolarity::Negative => "!",
-                };
-                let generated = format!("<a href=\"#{}\">{}{}</a>", encoded, prefix, out);
-                if links.insert(generated.clone()) { Some(generated) } else { None }
-            })
-            .collect::<Vec<String>>();
-        ret.sort();
-        ret
-    };
-
-    let concrete_format = format_impls(concrete, id_map);
-    let synthetic_format = format_impls(synthetic, id_map);
-    let blanket_format = format_impls(blanket_impl, id_map);
-
-    if !concrete_format.is_empty() {
-        print_sidebar_block(
-            out,
-            "trait-implementations",
-            "Trait Implementations",
-            concrete_format.iter(),
-        );
-    }
-
-    if !synthetic_format.is_empty() {
-        print_sidebar_block(
-            out,
-            "synthetic-implementations",
-            "Auto Trait Implementations",
-            synthetic_format.iter(),
-        );
-    }
-
-    if !blanket_format.is_empty() {
-        print_sidebar_block(
-            out,
-            "blanket-implementations",
-            "Blanket Implementations",
-            blanket_format.iter(),
-        );
-    }
-}
-
-fn sidebar_assoc_items(cx: &Context<'_>, out: &mut Buffer, it: &clean::Item) {
-    let did = it.item_id.expect_def_id();
-    let cache = cx.cache();
-
-    if let Some(v) = cache.impls.get(&did) {
-        let mut used_links = FxHashSet::default();
-        let mut id_map = IdMap::new();
-
-        {
-            let used_links_bor = &mut used_links;
-            let mut assoc_consts = v
-                .iter()
-                .filter(|i| i.inner_impl().trait_.is_none())
-                .flat_map(|i| get_associated_constants(i.inner_impl(), used_links_bor))
-                .collect::<Vec<_>>();
-            if !assoc_consts.is_empty() {
-                // We want links' order to be reproducible so we don't use unstable sort.
-                assoc_consts.sort();
-
-                print_sidebar_block(
-                    out,
-                    "implementations",
-                    "Associated Constants",
-                    assoc_consts.iter(),
-                );
-            }
-            let mut methods = v
-                .iter()
-                .filter(|i| i.inner_impl().trait_.is_none())
-                .flat_map(|i| get_methods(i.inner_impl(), false, used_links_bor, false, cx.tcx()))
-                .collect::<Vec<_>>();
-            if !methods.is_empty() {
-                // We want links' order to be reproducible so we don't use unstable sort.
-                methods.sort();
-
-                print_sidebar_block(out, "implementations", "Methods", methods.iter());
-            }
-        }
-
-        if v.iter().any(|i| i.inner_impl().trait_.is_some()) {
-            if let Some(impl_) =
-                v.iter().find(|i| i.trait_did() == cx.tcx().lang_items().deref_trait())
-            {
-                let mut derefs = DefIdSet::default();
-                derefs.insert(did);
-                sidebar_deref_methods(cx, out, impl_, v, &mut derefs, &mut used_links);
-            }
-
-            let (synthetic, concrete): (Vec<&Impl>, Vec<&Impl>) =
-                v.iter().partition::<Vec<_>, _>(|i| i.inner_impl().kind.is_auto());
-            let (blanket_impl, concrete): (Vec<&Impl>, Vec<&Impl>) =
-                concrete.into_iter().partition::<Vec<_>, _>(|i| i.inner_impl().kind.is_blanket());
-
-            sidebar_render_assoc_items(cx, out, &mut id_map, concrete, synthetic, blanket_impl);
-        }
-    }
-}
-
-fn sidebar_deref_methods(
-    cx: &Context<'_>,
-    out: &mut Buffer,
-    impl_: &Impl,
-    v: &[Impl],
-    derefs: &mut DefIdSet,
-    used_links: &mut FxHashSet<String>,
-) {
-    let c = cx.cache();
-
-    debug!("found Deref: {:?}", impl_);
-    if let Some((target, real_target)) =
-        impl_.inner_impl().items.iter().find_map(|item| match *item.kind {
-            clean::AssocTypeItem(box ref t, _) => Some(match *t {
-                clean::Typedef { item_type: Some(ref type_), .. } => (type_, &t.type_),
-                _ => (&t.type_, &t.type_),
-            }),
-            _ => None,
-        })
-    {
-        debug!("found target, real_target: {:?} {:?}", target, real_target);
-        if let Some(did) = target.def_id(c) &&
-            let Some(type_did) = impl_.inner_impl().for_.def_id(c) &&
-            // `impl Deref<Target = S> for S`
-            (did == type_did || !derefs.insert(did))
-        {
-            // Avoid infinite cycles
-            return;
-        }
-        let deref_mut = v.iter().any(|i| i.trait_did() == cx.tcx().lang_items().deref_mut_trait());
-        let inner_impl = target
-            .def_id(c)
-            .or_else(|| {
-                target.primitive_type().and_then(|prim| c.primitive_locations.get(&prim).cloned())
-            })
-            .and_then(|did| c.impls.get(&did));
-        if let Some(impls) = inner_impl {
-            debug!("found inner_impl: {:?}", impls);
-            let mut ret = impls
-                .iter()
-                .filter(|i| i.inner_impl().trait_.is_none())
-                .flat_map(|i| get_methods(i.inner_impl(), true, used_links, deref_mut, cx.tcx()))
-                .collect::<Vec<_>>();
-            if !ret.is_empty() {
-                let id = if let Some(target_def_id) = real_target.def_id(c) {
-                    cx.deref_id_map.get(&target_def_id).expect("Deref section without derived id")
-                } else {
-                    "deref-methods"
-                };
-                let title = format!(
-                    "Methods from {}&lt;Target={}&gt;",
-                    Escape(&format!("{:#}", impl_.inner_impl().trait_.as_ref().unwrap().print(cx))),
-                    Escape(&format!("{:#}", real_target.print(cx))),
-                );
-                // We want links' order to be reproducible so we don't use unstable sort.
-                ret.sort();
-                print_sidebar_block(out, id, &title, ret.iter());
-            }
-        }
-
-        // Recurse into any further impls that might exist for `target`
-        if let Some(target_did) = target.def_id(c) &&
-            let Some(target_impls) = c.impls.get(&target_did) &&
-            let Some(target_deref_impl) = target_impls.iter().find(|i| {
-                i.inner_impl()
-                    .trait_
-                    .as_ref()
-                    .map(|t| Some(t.def_id()) == cx.tcx().lang_items().deref_trait())
-                    .unwrap_or(false)
-            })
-        {
-            sidebar_deref_methods(
-                cx,
-                out,
-                target_deref_impl,
-                target_impls,
-                derefs,
-                used_links,
-            );
-        }
-    }
-}
-
-fn sidebar_struct(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, s: &clean::Struct) {
-    let mut sidebar = Buffer::new();
-    let fields = get_struct_fields_name(&s.fields);
-
-    if !fields.is_empty() {
-        match s.ctor_kind {
-            None => {
-                print_sidebar_block(&mut sidebar, "fields", "Fields", fields.iter());
-            }
-            Some(CtorKind::Fn) => print_sidebar_title(&mut sidebar, "fields", "Tuple Fields"),
-            Some(CtorKind::Const) => {}
-        }
-    }
-
-    sidebar_assoc_items(cx, &mut sidebar, it);
-
-    if !sidebar.is_empty() {
-        write!(buf, "<section>{}</section>", sidebar.into_inner());
-    }
-}
-
 fn get_id_for_impl(for_: &clean::Type, trait_: Option<&clean::Path>, cx: &Context<'_>) -> String {
     match trait_ {
         Some(t) => small_url_encode(format!("impl-{:#}-for-{:#}", t.print(cx), for_.print(cx))),
@@ -2340,131 +1965,6 @@ fn extract_for_impl_name(item: &clean::Item, cx: &Context<'_>) -> Option<(String
     }
 }
 
-fn print_sidebar_title(buf: &mut Buffer, id: &str, title: &str) {
-    write!(buf, "<h3><a href=\"#{}\">{}</a></h3>", id, title);
-}
-
-fn print_sidebar_block(
-    buf: &mut Buffer,
-    id: &str,
-    title: &str,
-    items: impl Iterator<Item = impl fmt::Display>,
-) {
-    print_sidebar_title(buf, id, title);
-    buf.push_str("<ul class=\"block\">");
-    for item in items {
-        write!(buf, "<li>{}</li>", item);
-    }
-    buf.push_str("</ul>");
-}
-
-fn sidebar_trait(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, t: &clean::Trait) {
-    buf.write_str("<section>");
-
-    fn print_sidebar_section(
-        out: &mut Buffer,
-        items: &[clean::Item],
-        id: &str,
-        title: &str,
-        filter: impl Fn(&clean::Item) -> bool,
-        mapper: impl Fn(&str) -> String,
-    ) {
-        let mut items: Vec<&str> = items
-            .iter()
-            .filter_map(|m| match m.name {
-                Some(ref name) if filter(m) => Some(name.as_str()),
-                _ => None,
-            })
-            .collect::<Vec<_>>();
-
-        if !items.is_empty() {
-            items.sort_unstable();
-            print_sidebar_block(out, id, title, items.into_iter().map(mapper));
-        }
-    }
-
-    print_sidebar_section(
-        buf,
-        &t.items,
-        "required-associated-types",
-        "Required Associated Types",
-        |m| m.is_ty_associated_type(),
-        |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::AssocType),
-    );
-
-    print_sidebar_section(
-        buf,
-        &t.items,
-        "provided-associated-types",
-        "Provided Associated Types",
-        |m| m.is_associated_type(),
-        |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::AssocType),
-    );
-
-    print_sidebar_section(
-        buf,
-        &t.items,
-        "required-associated-consts",
-        "Required Associated Constants",
-        |m| m.is_ty_associated_const(),
-        |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::AssocConst),
-    );
-
-    print_sidebar_section(
-        buf,
-        &t.items,
-        "provided-associated-consts",
-        "Provided Associated Constants",
-        |m| m.is_associated_const(),
-        |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::AssocConst),
-    );
-
-    print_sidebar_section(
-        buf,
-        &t.items,
-        "required-methods",
-        "Required Methods",
-        |m| m.is_ty_method(),
-        |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::TyMethod),
-    );
-
-    print_sidebar_section(
-        buf,
-        &t.items,
-        "provided-methods",
-        "Provided Methods",
-        |m| m.is_method(),
-        |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::Method),
-    );
-
-    if let Some(implementors) = cx.cache().implementors.get(&it.item_id.expect_def_id()) {
-        let mut res = implementors
-            .iter()
-            .filter(|i| !i.is_on_local_type(cx))
-            .filter_map(|i| extract_for_impl_name(&i.impl_item, cx))
-            .collect::<Vec<_>>();
-
-        if !res.is_empty() {
-            res.sort();
-            print_sidebar_block(
-                buf,
-                "foreign-impls",
-                "Implementations on Foreign Types",
-                res.iter().map(|(name, id)| format!("<a href=\"#{}\">{}</a>", id, Escape(name))),
-            );
-        }
-    }
-
-    sidebar_assoc_items(cx, buf, it);
-
-    print_sidebar_title(buf, "implementors", "Implementors");
-    if t.is_auto(cx.tcx()) {
-        print_sidebar_title(buf, "synthetic-implementors", "Auto Implementors");
-    }
-
-    buf.push_str("</section>")
-}
-
 /// Returns the list of implementations for the primitive reference type, filtering out any
 /// implementations that are on concrete or partially generic types, only keeping implementations
 /// of the form `impl<T> Trait for &T`.
@@ -2495,89 +1995,6 @@ pub(crate) fn get_filtered_impls_for_reference<'a>(
     (concrete, synthetic, blanket_impl)
 }
 
-fn sidebar_primitive(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item) {
-    let mut sidebar = Buffer::new();
-
-    if it.name.map(|n| n.as_str() != "reference").unwrap_or(false) {
-        sidebar_assoc_items(cx, &mut sidebar, it);
-    } else {
-        let shared = Rc::clone(&cx.shared);
-        let (concrete, synthetic, blanket_impl) = get_filtered_impls_for_reference(&shared, it);
-
-        sidebar_render_assoc_items(
-            cx,
-            &mut sidebar,
-            &mut IdMap::new(),
-            concrete,
-            synthetic,
-            blanket_impl,
-        );
-    }
-
-    if !sidebar.is_empty() {
-        write!(buf, "<section>{}</section>", sidebar.into_inner());
-    }
-}
-
-fn sidebar_typedef(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item) {
-    let mut sidebar = Buffer::new();
-    sidebar_assoc_items(cx, &mut sidebar, it);
-
-    if !sidebar.is_empty() {
-        write!(buf, "<section>{}</section>", sidebar.into_inner());
-    }
-}
-
-fn get_struct_fields_name(fields: &[clean::Item]) -> Vec<String> {
-    let mut fields = fields
-        .iter()
-        .filter(|f| matches!(*f.kind, clean::StructFieldItem(..)))
-        .filter_map(|f| {
-            f.name.map(|name| format!("<a href=\"#structfield.{name}\">{name}</a>", name = name))
-        })
-        .collect::<Vec<_>>();
-    fields.sort();
-    fields
-}
-
-fn sidebar_union(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, u: &clean::Union) {
-    let mut sidebar = Buffer::new();
-    let fields = get_struct_fields_name(&u.fields);
-
-    if !fields.is_empty() {
-        print_sidebar_block(&mut sidebar, "fields", "Fields", fields.iter());
-    }
-
-    sidebar_assoc_items(cx, &mut sidebar, it);
-
-    if !sidebar.is_empty() {
-        write!(buf, "<section>{}</section>", sidebar.into_inner());
-    }
-}
-
-fn sidebar_enum(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, e: &clean::Enum) {
-    let mut sidebar = Buffer::new();
-
-    let mut variants = e
-        .variants()
-        .filter_map(|v| {
-            v.name
-                .as_ref()
-                .map(|name| format!("<a href=\"#variant.{name}\">{name}</a>", name = name))
-        })
-        .collect::<Vec<_>>();
-    if !variants.is_empty() {
-        variants.sort_unstable();
-        print_sidebar_block(&mut sidebar, "variants", "Variants", variants.iter());
-    }
-
-    sidebar_assoc_items(cx, &mut sidebar, it);
-
-    if !sidebar.is_empty() {
-        write!(buf, "<section>{}</section>", sidebar.into_inner());
-    }
-}
-
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 pub(crate) enum ItemSection {
     Reexports,
@@ -2731,54 +2148,6 @@ fn item_ty_to_section(ty: ItemType) -> ItemSection {
     }
 }
 
-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();
-
-    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());
-    }
-
-    if !sidebar.is_empty() {
-        write!(
-            buf,
-            "<section>\
-                 <ul class=\"block\">{}</ul>\
-             </section>",
-            sidebar
-        );
-    }
-}
-
-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);
-
-    if !sidebar.is_empty() {
-        write!(buf, "<section>{}</section>", sidebar.into_inner());
-    }
-}
-
 /// Returns a list of all paths used in the type.
 /// This is used to help deduplicate imported impls
 /// for reexported types. If any of the contained

src/librustdoc/html/render/sidebar.rs

@@ -0,0 +1,561 @@
+use std::{borrow::Cow, rc::Rc};
+
+use askama::Template;
+use rustc_data_structures::fx::FxHashSet;
+use rustc_hir::{def::CtorKind, def_id::DefIdSet};
+use rustc_middle::ty::{self, TyCtxt};
+
+use crate::{
+    clean,
+    formats::{item_type::ItemType, Impl},
+    html::{format::Buffer, markdown::IdMap},
+};
+
+use super::{item_ty_to_section, Context, ItemSection};
+
+#[derive(Template)]
+#[template(path = "sidebar.html")]
+pub(super) struct Sidebar<'a> {
+    pub(super) title_prefix: &'static str,
+    pub(super) title: &'a str,
+    pub(super) is_crate: bool,
+    pub(super) version: &'a str,
+    pub(super) blocks: Vec<LinkBlock<'a>>,
+    pub(super) path: String,
+}
+
+impl<'a> Sidebar<'a> {
+    /// Only create a `<section>` if there are any blocks
+    /// which should actually be rendered.
+    pub fn should_render_blocks(&self) -> bool {
+        self.blocks.iter().any(LinkBlock::should_render)
+    }
+}
+
+/// A sidebar section such as 'Methods'.
+pub(crate) struct LinkBlock<'a> {
+    /// The name of this section, e.g. 'Methods'
+    /// as well as the link to it, e.g. `#implementations`.
+    /// Will be rendered inside an `<h3>` tag
+    heading: Link<'a>,
+    links: Vec<Link<'a>>,
+    /// Render the heading even if there are no links
+    force_render: bool,
+}
+
+impl<'a> LinkBlock<'a> {
+    pub fn new(heading: Link<'a>, links: Vec<Link<'a>>) -> Self {
+        Self { heading, links, force_render: false }
+    }
+
+    pub fn forced(heading: Link<'a>) -> Self {
+        Self { heading, links: vec![], force_render: true }
+    }
+
+    pub fn should_render(&self) -> bool {
+        self.force_render || !self.links.is_empty()
+    }
+}
+
+/// A link to an item. Content should not be escaped.
+#[derive(PartialOrd, Ord, PartialEq, Eq, Hash, Clone)]
+pub(crate) struct Link<'a> {
+    /// The content for the anchor tag
+    name: Cow<'a, str>,
+    /// The id of an anchor within the page (without a `#` prefix)
+    href: Cow<'a, str>,
+}
+
+impl<'a> Link<'a> {
+    pub fn new(href: impl Into<Cow<'a, str>>, name: impl Into<Cow<'a, str>>) -> Self {
+        Self { href: href.into(), name: name.into() }
+    }
+    pub fn empty() -> Link<'static> {
+        Link::new("", "")
+    }
+}
+
+pub(super) fn print_sidebar(cx: &Context<'_>, it: &clean::Item, buffer: &mut Buffer) {
+    let blocks: Vec<LinkBlock<'_>> = match *it.kind {
+        clean::StructItem(ref s) => sidebar_struct(cx, it, s),
+        clean::TraitItem(ref t) => sidebar_trait(cx, it, t),
+        clean::PrimitiveItem(_) => sidebar_primitive(cx, it),
+        clean::UnionItem(ref u) => sidebar_union(cx, it, u),
+        clean::EnumItem(ref e) => sidebar_enum(cx, it, e),
+        clean::TypedefItem(_) => sidebar_typedef(cx, it),
+        clean::ModuleItem(ref m) => vec![sidebar_module(&m.items)],
+        clean::ForeignTypeItem => sidebar_foreign_type(cx, it),
+        _ => vec![],
+    };
+    // The sidebar is designed to display sibling functions, modules and
+    // other miscellaneous information. since there are lots of sibling
+    // items (and that causes quadratic growth in large modules),
+    // we refactor common parts into a shared JavaScript file per module.
+    // still, we don't move everything into JS because we want to preserve
+    // as much HTML as possible in order to allow non-JS-enabled browsers
+    // to navigate the documentation (though slightly inefficiently).
+    let (title_prefix, title) = if it.is_struct()
+        || it.is_trait()
+        || it.is_primitive()
+        || it.is_union()
+        || it.is_enum()
+        || it.is_mod()
+        || it.is_typedef()
+    {
+        (
+            match *it.kind {
+                clean::ModuleItem(..) if it.is_crate() => "Crate ",
+                clean::ModuleItem(..) => "Module ",
+                _ => "",
+            },
+            it.name.as_ref().unwrap().as_str(),
+        )
+    } else {
+        ("", "")
+    };
+    let version = if it.is_crate() {
+        cx.cache().crate_version.as_ref().map(String::as_str).unwrap_or_default()
+    } else {
+        ""
+    };
+    let path: String = if !it.is_mod() {
+        cx.current.iter().map(|s| s.as_str()).intersperse("::").collect()
+    } else {
+        "".into()
+    };
+    let sidebar = Sidebar { title_prefix, title, is_crate: it.is_crate(), version, blocks, path };
+    sidebar.render_into(buffer).unwrap();
+}
+
+fn get_struct_fields_name<'a>(fields: &'a [clean::Item]) -> Vec<Link<'a>> {
+    let mut fields = fields
+        .iter()
+        .filter(|f| matches!(*f.kind, clean::StructFieldItem(..)))
+        .filter_map(|f| {
+            f.name.as_ref().map(|name| Link::new(format!("structfield.{name}"), name.as_str()))
+        })
+        .collect::<Vec<Link<'a>>>();
+    fields.sort();
+    fields
+}
+
+fn sidebar_struct<'a>(
+    cx: &'a Context<'_>,
+    it: &'a clean::Item,
+    s: &'a clean::Struct,
+) -> Vec<LinkBlock<'a>> {
+    let fields = get_struct_fields_name(&s.fields);
+    let field_name = match s.ctor_kind {
+        Some(CtorKind::Fn) => Some("Tuple Fields"),
+        None => Some("Fields"),
+        _ => None,
+    };
+    let mut items = vec![];
+    if let Some(name) = field_name {
+        items.push(LinkBlock::new(Link::new("fields", name), fields));
+    }
+    sidebar_assoc_items(cx, it, &mut items);
+    items
+}
+
+fn sidebar_trait<'a>(
+    cx: &'a Context<'_>,
+    it: &'a clean::Item,
+    t: &'a clean::Trait,
+) -> Vec<LinkBlock<'a>> {
+    fn filter_items<'a>(
+        items: &'a [clean::Item],
+        filt: impl Fn(&clean::Item) -> bool,
+        ty: &str,
+    ) -> Vec<Link<'a>> {
+        let mut res = items
+            .iter()
+            .filter_map(|m: &clean::Item| match m.name {
+                Some(ref name) if filt(m) => Some(Link::new(format!("{ty}.{name}"), name.as_str())),
+                _ => None,
+            })
+            .collect::<Vec<Link<'a>>>();
+        res.sort();
+        res
+    }
+
+    let req_assoc = filter_items(&t.items, |m| m.is_ty_associated_type(), "associatedtype");
+    let prov_assoc = filter_items(&t.items, |m| m.is_associated_type(), "associatedtype");
+    let req_assoc_const =
+        filter_items(&t.items, |m| m.is_ty_associated_const(), "associatedconstant");
+    let prov_assoc_const =
+        filter_items(&t.items, |m| m.is_associated_const(), "associatedconstant");
+    let req_method = filter_items(&t.items, |m| m.is_ty_method(), "tymethod");
+    let prov_method = filter_items(&t.items, |m| m.is_method(), "method");
+    let mut foreign_impls = vec![];
+    if let Some(implementors) = cx.cache().implementors.get(&it.item_id.expect_def_id()) {
+        foreign_impls.extend(
+            implementors
+                .iter()
+                .filter(|i| !i.is_on_local_type(cx))
+                .filter_map(|i| super::extract_for_impl_name(&i.impl_item, cx))
+                .map(|(name, id)| Link::new(id, name)),
+        );
+        foreign_impls.sort();
+    }
+
+    let mut blocks: Vec<LinkBlock<'_>> = [
+        ("required-associated-types", "Required Associated Types", req_assoc),
+        ("provided-associated-types", "Provided Associated Types", prov_assoc),
+        ("required-associated-consts", "Required Associated Constants", req_assoc_const),
+        ("provided-associated-consts", "Provided Associated Constants", prov_assoc_const),
+        ("required-methods", "Required Methods", req_method),
+        ("provided-methods", "Provided Methods", prov_method),
+        ("foreign-impls", "Implementations on Foreign Types", foreign_impls),
+    ]
+    .into_iter()
+    .map(|(id, title, items)| LinkBlock::new(Link::new(id, title), items))
+    .collect();
+    sidebar_assoc_items(cx, it, &mut blocks);
+    blocks.push(LinkBlock::forced(Link::new("implementors", "Implementors")));
+    if t.is_auto(cx.tcx()) {
+        blocks.push(LinkBlock::forced(Link::new("synthetic-implementors", "Auto Implementors")));
+    }
+    blocks
+}
+
+fn sidebar_primitive<'a>(cx: &'a Context<'_>, it: &'a clean::Item) -> Vec<LinkBlock<'a>> {
+    if it.name.map(|n| n.as_str() != "reference").unwrap_or(false) {
+        let mut items = vec![];
+        sidebar_assoc_items(cx, it, &mut items);
+        items
+    } else {
+        let shared = Rc::clone(&cx.shared);
+        let (concrete, synthetic, blanket_impl) =
+            super::get_filtered_impls_for_reference(&shared, it);
+
+        sidebar_render_assoc_items(cx, &mut IdMap::new(), concrete, synthetic, blanket_impl).into()
+    }
+}
+
+fn sidebar_typedef<'a>(cx: &'a Context<'_>, it: &'a clean::Item) -> Vec<LinkBlock<'a>> {
+    let mut items = vec![];
+    sidebar_assoc_items(cx, it, &mut items);
+    items
+}
+
+fn sidebar_union<'a>(
+    cx: &'a Context<'_>,
+    it: &'a clean::Item,
+    u: &'a clean::Union,
+) -> Vec<LinkBlock<'a>> {
+    let fields = get_struct_fields_name(&u.fields);
+    let mut items = vec![LinkBlock::new(Link::new("fields", "Fields"), fields)];
+    sidebar_assoc_items(cx, it, &mut items);
+    items
+}
+
+/// Adds trait implementations into the blocks of links
+fn sidebar_assoc_items<'a>(
+    cx: &'a Context<'_>,
+    it: &'a clean::Item,
+    links: &mut Vec<LinkBlock<'a>>,
+) {
+    let did = it.item_id.expect_def_id();
+    let cache = cx.cache();
+
+    let mut assoc_consts = Vec::new();
+    let mut methods = Vec::new();
+    if let Some(v) = cache.impls.get(&did) {
+        let mut used_links = FxHashSet::default();
+        let mut id_map = IdMap::new();
+
+        {
+            let used_links_bor = &mut used_links;
+            assoc_consts.extend(
+                v.iter()
+                    .filter(|i| i.inner_impl().trait_.is_none())
+                    .flat_map(|i| get_associated_constants(i.inner_impl(), used_links_bor)),
+            );
+            // We want links' order to be reproducible so we don't use unstable sort.
+            assoc_consts.sort();
+
+            #[rustfmt::skip] // rustfmt makes the pipeline less readable
+            methods.extend(
+                v.iter()
+                    .filter(|i| i.inner_impl().trait_.is_none())
+                    .flat_map(|i| get_methods(i.inner_impl(), false, used_links_bor, false, cx.tcx())),
+            );
+
+            // We want links' order to be reproducible so we don't use unstable sort.
+            methods.sort();
+        }
+
+        let mut deref_methods = Vec::new();
+        let [concrete, synthetic, blanket] = if v.iter().any(|i| i.inner_impl().trait_.is_some()) {
+            if let Some(impl_) =
+                v.iter().find(|i| i.trait_did() == cx.tcx().lang_items().deref_trait())
+            {
+                let mut derefs = DefIdSet::default();
+                derefs.insert(did);
+                sidebar_deref_methods(
+                    cx,
+                    &mut deref_methods,
+                    impl_,
+                    v,
+                    &mut derefs,
+                    &mut used_links,
+                );
+            }
+
+            let (synthetic, concrete): (Vec<&Impl>, Vec<&Impl>) =
+                v.iter().partition::<Vec<_>, _>(|i| i.inner_impl().kind.is_auto());
+            let (blanket_impl, concrete): (Vec<&Impl>, Vec<&Impl>) =
+                concrete.into_iter().partition::<Vec<_>, _>(|i| i.inner_impl().kind.is_blanket());
+
+            sidebar_render_assoc_items(cx, &mut id_map, concrete, synthetic, blanket_impl)
+        } else {
+            std::array::from_fn(|_| LinkBlock::new(Link::empty(), vec![]))
+        };
+
+        let mut blocks = vec![
+            LinkBlock::new(Link::new("implementations", "Associated Constants"), assoc_consts),
+            LinkBlock::new(Link::new("implementations", "Methods"), methods),
+        ];
+        blocks.append(&mut deref_methods);
+        blocks.extend([concrete, synthetic, blanket]);
+        links.append(&mut blocks);
+    }
+}
+
+fn sidebar_deref_methods<'a>(
+    cx: &'a Context<'_>,
+    out: &mut Vec<LinkBlock<'a>>,
+    impl_: &Impl,
+    v: &[Impl],
+    derefs: &mut DefIdSet,
+    used_links: &mut FxHashSet<String>,
+) {
+    let c = cx.cache();
+
+    debug!("found Deref: {:?}", impl_);
+    if let Some((target, real_target)) =
+        impl_.inner_impl().items.iter().find_map(|item| match *item.kind {
+            clean::AssocTypeItem(box ref t, _) => Some(match *t {
+                clean::Typedef { item_type: Some(ref type_), .. } => (type_, &t.type_),
+                _ => (&t.type_, &t.type_),
+            }),
+            _ => None,
+        })
+    {
+        debug!("found target, real_target: {:?} {:?}", target, real_target);
+        if let Some(did) = target.def_id(c) &&
+            let Some(type_did) = impl_.inner_impl().for_.def_id(c) &&
+            // `impl Deref<Target = S> for S`
+            (did == type_did || !derefs.insert(did))
+        {
+            // Avoid infinite cycles
+            return;
+        }
+        let deref_mut = v.iter().any(|i| i.trait_did() == cx.tcx().lang_items().deref_mut_trait());
+        let inner_impl = target
+            .def_id(c)
+            .or_else(|| {
+                target.primitive_type().and_then(|prim| c.primitive_locations.get(&prim).cloned())
+            })
+            .and_then(|did| c.impls.get(&did));
+        if let Some(impls) = inner_impl {
+            debug!("found inner_impl: {:?}", impls);
+            let mut ret = impls
+                .iter()
+                .filter(|i| i.inner_impl().trait_.is_none())
+                .flat_map(|i| get_methods(i.inner_impl(), true, used_links, deref_mut, cx.tcx()))
+                .collect::<Vec<_>>();
+            if !ret.is_empty() {
+                let id = if let Some(target_def_id) = real_target.def_id(c) {
+                    Cow::Borrowed(
+                        cx.deref_id_map
+                            .get(&target_def_id)
+                            .expect("Deref section without derived id")
+                            .as_str(),
+                    )
+                } else {
+                    Cow::Borrowed("deref-methods")
+                };
+                let title = format!(
+                    "Methods from {:#}<Target={:#}>",
+                    impl_.inner_impl().trait_.as_ref().unwrap().print(cx),
+                    real_target.print(cx),
+                );
+                // We want links' order to be reproducible so we don't use unstable sort.
+                ret.sort();
+                out.push(LinkBlock::new(Link::new(id, title), ret));
+            }
+        }
+
+        // Recurse into any further impls that might exist for `target`
+        if let Some(target_did) = target.def_id(c) &&
+            let Some(target_impls) = c.impls.get(&target_did) &&
+            let Some(target_deref_impl) = target_impls.iter().find(|i| {
+                i.inner_impl()
+                    .trait_
+                    .as_ref()
+                    .map(|t| Some(t.def_id()) == cx.tcx().lang_items().deref_trait())
+                    .unwrap_or(false)
+            })
+        {
+            sidebar_deref_methods(
+                cx,
+                out,
+                target_deref_impl,
+                target_impls,
+                derefs,
+                used_links,
+            );
+        }
+    }
+}
+
+fn sidebar_enum<'a>(
+    cx: &'a Context<'_>,
+    it: &'a clean::Item,
+    e: &'a clean::Enum,
+) -> Vec<LinkBlock<'a>> {
+    let mut variants = e
+        .variants()
+        .filter_map(|v| v.name)
+        .map(|name| Link::new(format!("variant.{name}"), name.to_string()))
+        .collect::<Vec<_>>();
+    variants.sort_unstable();
+
+    let mut items = vec![LinkBlock::new(Link::new("variants", "Variants"), variants)];
+    sidebar_assoc_items(cx, it, &mut items);
+    items
+}
+
+pub(crate) fn sidebar_module_like(
+    item_sections_in_use: FxHashSet<ItemSection>,
+) -> LinkBlock<'static> {
+    let item_sections = ItemSection::ALL
+        .iter()
+        .copied()
+        .filter(|sec| item_sections_in_use.contains(sec))
+        .map(|sec| Link::new(sec.id(), sec.name()))
+        .collect();
+    LinkBlock::new(Link::empty(), item_sections)
+}
+
+fn sidebar_module(items: &[clean::Item]) -> LinkBlock<'static> {
+    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(item_sections_in_use)
+}
+
+fn sidebar_foreign_type<'a>(cx: &'a Context<'_>, it: &'a clean::Item) -> Vec<LinkBlock<'a>> {
+    let mut items = vec![];
+    sidebar_assoc_items(cx, it, &mut items);
+    items
+}
+
+/// Renders the trait implementations for this type
+fn sidebar_render_assoc_items(
+    cx: &Context<'_>,
+    id_map: &mut IdMap,
+    concrete: Vec<&Impl>,
+    synthetic: Vec<&Impl>,
+    blanket_impl: Vec<&Impl>,
+) -> [LinkBlock<'static>; 3] {
+    let format_impls = |impls: Vec<&Impl>, id_map: &mut IdMap| {
+        let mut links = FxHashSet::default();
+
+        let mut ret = impls
+            .iter()
+            .filter_map(|it| {
+                let trait_ = it.inner_impl().trait_.as_ref()?;
+                let encoded =
+                    id_map.derive(super::get_id_for_impl(&it.inner_impl().for_, Some(trait_), cx));
+
+                let prefix = match it.inner_impl().polarity {
+                    ty::ImplPolarity::Positive | ty::ImplPolarity::Reservation => "",
+                    ty::ImplPolarity::Negative => "!",
+                };
+                let generated = Link::new(encoded, format!("{prefix}{:#}", trait_.print(cx)));
+                if links.insert(generated.clone()) { Some(generated) } else { None }
+            })
+            .collect::<Vec<Link<'static>>>();
+        ret.sort();
+        ret
+    };
+
+    let concrete = format_impls(concrete, id_map);
+    let synthetic = format_impls(synthetic, id_map);
+    let blanket = format_impls(blanket_impl, id_map);
+    [
+        LinkBlock::new(Link::new("trait-implementations", "Trait Implementations"), concrete),
+        LinkBlock::new(
+            Link::new("synthetic-implementations", "Auto Trait Implementations"),
+            synthetic,
+        ),
+        LinkBlock::new(Link::new("blanket-implementations", "Blanket Implementations"), blanket),
+    ]
+}
+
+fn get_next_url(used_links: &mut FxHashSet<String>, url: String) -> String {
+    if used_links.insert(url.clone()) {
+        return url;
+    }
+    let mut add = 1;
+    while !used_links.insert(format!("{}-{}", url, add)) {
+        add += 1;
+    }
+    format!("{}-{}", url, add)
+}
+
+fn get_methods<'a>(
+    i: &'a clean::Impl,
+    for_deref: bool,
+    used_links: &mut FxHashSet<String>,
+    deref_mut: bool,
+    tcx: TyCtxt<'_>,
+) -> Vec<Link<'a>> {
+    i.items
+        .iter()
+        .filter_map(|item| match item.name {
+            Some(ref name) if !name.is_empty() && item.is_method() => {
+                if !for_deref || super::should_render_item(item, deref_mut, tcx) {
+                    Some(Link::new(
+                        get_next_url(used_links, format!("{}.{}", ItemType::Method, name)),
+                        name.as_str(),
+                    ))
+                } else {
+                    None
+                }
+            }
+            _ => None,
+        })
+        .collect::<Vec<_>>()
+}
+
+fn get_associated_constants<'a>(
+    i: &'a clean::Impl,
+    used_links: &mut FxHashSet<String>,
+) -> Vec<Link<'a>> {
+    i.items
+        .iter()
+        .filter_map(|item| match item.name {
+            Some(ref name) if !name.is_empty() && item.is_associated_const() => Some(Link::new(
+                get_next_url(used_links, format!("{}.{}", ItemType::AssocConst, name)),
+                name.as_str(),
+            )),
+            _ => None,
+        })
+        .collect::<Vec<_>>()
+}

src/librustdoc/html/templates/sidebar.html

@@ -0,0 +1,37 @@
+{% if !title.is_empty() %}
+    <h2 class="location"> {# #}
+        <a href="#">{{title_prefix}}{{title}}</a> {# #}
+    </h2>
+{% endif %}
+<div class="sidebar-elems">
+    {% if is_crate %}
+        <ul class="block">
+            {% if !version.is_empty() %}
+                <li class="version">Version {{+ version}}</li>
+            {% endif %}
+            <li><a id="all-types" href="all.html">All Items</a></li> {# #}
+        </ul>
+    {% endif %}
+
+    {% if self.should_render_blocks() %}
+        <section>
+            {% for block in blocks %}
+                {% if block.should_render() %}
+                    {% if !block.heading.name.is_empty() %}
+                        <h3><a href="#{{block.heading.href|safe}}">{{block.heading.name}}</a></h3>
+                    {% endif %}
+                    {% if !block.links.is_empty() %}
+                        <ul class="block">
+                            {% for link in block.links %}
+                                <li><a href="#{{link.href|safe}}">{{link.name}}</a></li>
+                            {% endfor %}
+                        </ul>
+                    {% endif %}
+                {% endif %}
+            {% endfor %}
+        </section>
+    {% endif %}
+    {% if !path.is_empty() %}
+        <h2><a href="index.html">In {{+ path}}</a></h2>
+    {% endif %}
+</div>