1 //! Rustdoc's HTML rendering module.
3 //! This modules contains the bulk of the logic necessary for rendering a
4 //! rustdoc `clean::Crate` instance to a set of static HTML pages. This
5 //! rendering process is largely driven by the `format!` syntax extension to
6 //! perform all I/O into files and streams.
8 //! The rendering process is largely driven by the `Context` and `Cache`
9 //! structures. The cache is pre-populated by crawling the crate in question,
10 //! and then it is shared among the various rendering threads. The cache is meant
11 //! to be a fairly large structure not implementing `Clone` (because it's shared
12 //! among threads). The context, however, should be a lightweight structure. This
13 //! is cloned per-thread and contains information about what is currently being
16 //! In order to speed up rendering (mostly because of markdown rendering), the
17 //! rendering process has been parallelized. This parallelization is only
18 //! exposed through the `crate` method on the context, and then also from the
19 //! fact that the shared cache is stored in TLS (and must be accessed as such).
21 //! In addition to rendering the crate itself, this module is also responsible
22 //! for creating the corresponding search index and source file renderings.
23 //! These threads are not parallelized (they haven't been a bottleneck yet), and
24 //! both occur before the crate is rendered.
26 pub(crate) mod search_index;
36 pub(crate) use self::context::*;
37 pub(crate) use self::span_map::{collect_spans_and_sources, LinkFromSrc};
39 use std::collections::VecDeque;
40 use std::default::Default;
43 use std::iter::Peekable;
44 use std::path::PathBuf;
47 use std::string::ToString;
49 use rustc_ast_pretty::pprust;
50 use rustc_attr::{ConstStability, Deprecation, StabilityLevel};
51 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
52 use rustc_hir::def::CtorKind;
53 use rustc_hir::def_id::{DefId, DefIdSet};
54 use rustc_hir::Mutability;
55 use rustc_middle::middle::stability;
57 use rustc_middle::ty::TyCtxt;
59 symbol::{sym, Symbol},
60 BytePos, FileName, RealFileName,
62 use serde::ser::{SerializeMap, SerializeSeq};
63 use serde::{Serialize, Serializer};
65 use crate::clean::{self, ItemId, RenderedLink, SelfTy};
66 use crate::error::Error;
67 use crate::formats::cache::Cache;
68 use crate::formats::item_type::ItemType;
69 use crate::formats::{AssocItemRender, Impl, RenderMode};
70 use crate::html::escape::Escape;
71 use crate::html::format::{
72 href, join_with_double_colon, print_abi_with_space, print_constness_with_space,
73 print_default_space, print_generic_bounds, print_where_clause, visibility_print_with_space,
74 Buffer, Ending, HrefError, PrintWithSpace,
76 use crate::html::highlight;
77 use crate::html::markdown::{
78 HeadingOffset, IdMap, Markdown, MarkdownItemInfo, MarkdownSummaryLine,
80 use crate::html::sources;
81 use crate::html::static_files::SCRAPE_EXAMPLES_HELP_MD;
82 use crate::scrape_examples::{CallData, CallLocation};
84 use crate::DOC_RUST_LANG_ORG_CHANNEL;
86 /// A pair of name and its optional document.
87 pub(crate) type NameDoc = (String, Option<String>);
89 pub(crate) fn ensure_trailing_slash(v: &str) -> impl fmt::Display + '_ {
90 crate::html::format::display_fn(move |f| {
91 if !v.ends_with('/') && !v.is_empty() { write!(f, "{}/", v) } else { f.write_str(v) }
95 // Helper structs for rendering items/sidebars and carrying along contextual
98 /// Struct representing one entry in the JS search index. These are all emitted
99 /// by hand to a large JS file at the end of cache-creation.
101 pub(crate) struct IndexItem {
102 pub(crate) ty: ItemType,
103 pub(crate) name: Symbol,
104 pub(crate) path: String,
105 pub(crate) desc: String,
106 pub(crate) parent: Option<DefId>,
107 pub(crate) parent_idx: Option<usize>,
108 pub(crate) search_type: Option<IndexItemFunctionType>,
109 pub(crate) aliases: Box<[Symbol]>,
112 /// A type used for the search index.
114 pub(crate) struct RenderType {
115 id: Option<RenderTypeId>,
116 generics: Option<Vec<RenderType>>,
119 impl Serialize for RenderType {
120 fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
124 let id = match &self.id {
125 // 0 is a sentinel, everything else is one-indexed
127 Some(RenderTypeId::Index(idx)) => idx + 1,
128 _ => panic!("must convert render types to indexes before serializing"),
130 if let Some(generics) = &self.generics {
131 let mut seq = serializer.serialize_seq(None)?;
132 seq.serialize_element(&id)?;
133 seq.serialize_element(generics)?;
136 id.serialize(serializer)
141 #[derive(Clone, Debug)]
142 pub(crate) enum RenderTypeId {
144 Primitive(clean::PrimitiveType),
148 /// Full type of functions/methods in the search index.
150 pub(crate) struct IndexItemFunctionType {
151 inputs: Vec<RenderType>,
152 output: Vec<RenderType>,
155 impl Serialize for IndexItemFunctionType {
156 fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
160 // If we couldn't figure out a type, just write `0`.
161 let has_missing = self
164 .chain(self.output.iter())
165 .any(|i| i.id.is_none() && i.generics.is_none());
167 0.serialize(serializer)
169 let mut seq = serializer.serialize_seq(None)?;
170 match &self.inputs[..] {
171 [one] if one.generics.is_none() => seq.serialize_element(one)?,
172 _ => seq.serialize_element(&self.inputs)?,
174 match &self.output[..] {
176 [one] if one.generics.is_none() => seq.serialize_element(one)?,
177 _ => seq.serialize_element(&self.output)?,
184 #[derive(Debug, Clone)]
185 pub(crate) struct StylePath {
186 /// The path to the theme
187 pub(crate) path: PathBuf,
191 pub(crate) fn basename(&self) -> Result<String, Error> {
192 Ok(try_none!(try_none!(self.path.file_stem(), &self.path).to_str(), &self.path).to_string())
196 #[derive(Debug, Eq, PartialEq, Hash)]
203 fn new(mut url: String, name: String) -> ItemEntry {
204 while url.starts_with('/') {
207 ItemEntry { url, name }
212 pub(crate) fn print(&self) -> impl fmt::Display + '_ {
213 crate::html::format::display_fn(move |f| {
214 write!(f, "<a href=\"{}\">{}</a>", self.url, Escape(&self.name))
219 impl PartialOrd for ItemEntry {
220 fn partial_cmp(&self, other: &ItemEntry) -> Option<::std::cmp::Ordering> {
221 Some(self.cmp(other))
225 impl Ord for ItemEntry {
226 fn cmp(&self, other: &ItemEntry) -> ::std::cmp::Ordering {
227 self.name.cmp(&other.name)
233 structs: FxHashSet<ItemEntry>,
234 enums: FxHashSet<ItemEntry>,
235 unions: FxHashSet<ItemEntry>,
236 primitives: FxHashSet<ItemEntry>,
237 traits: FxHashSet<ItemEntry>,
238 macros: FxHashSet<ItemEntry>,
239 functions: FxHashSet<ItemEntry>,
240 typedefs: FxHashSet<ItemEntry>,
241 opaque_tys: FxHashSet<ItemEntry>,
242 statics: FxHashSet<ItemEntry>,
243 constants: FxHashSet<ItemEntry>,
244 attribute_macros: FxHashSet<ItemEntry>,
245 derive_macros: FxHashSet<ItemEntry>,
246 trait_aliases: FxHashSet<ItemEntry>,
250 fn new() -> AllTypes {
251 let new_set = |cap| FxHashSet::with_capacity_and_hasher(cap, Default::default());
253 structs: new_set(100),
255 unions: new_set(100),
256 primitives: new_set(26),
257 traits: new_set(100),
258 macros: new_set(100),
259 functions: new_set(100),
260 typedefs: new_set(100),
261 opaque_tys: new_set(100),
262 statics: new_set(100),
263 constants: new_set(100),
264 attribute_macros: new_set(100),
265 derive_macros: new_set(100),
266 trait_aliases: new_set(100),
270 fn append(&mut self, item_name: String, item_type: &ItemType) {
271 let mut url: Vec<_> = item_name.split("::").skip(1).collect();
272 if let Some(name) = url.pop() {
273 let new_url = format!("{}/{}.{}.html", url.join("/"), item_type, name);
275 let name = url.join("::");
277 ItemType::Struct => self.structs.insert(ItemEntry::new(new_url, name)),
278 ItemType::Enum => self.enums.insert(ItemEntry::new(new_url, name)),
279 ItemType::Union => self.unions.insert(ItemEntry::new(new_url, name)),
280 ItemType::Primitive => self.primitives.insert(ItemEntry::new(new_url, name)),
281 ItemType::Trait => self.traits.insert(ItemEntry::new(new_url, name)),
282 ItemType::Macro => self.macros.insert(ItemEntry::new(new_url, name)),
283 ItemType::Function => self.functions.insert(ItemEntry::new(new_url, name)),
284 ItemType::Typedef => self.typedefs.insert(ItemEntry::new(new_url, name)),
285 ItemType::OpaqueTy => self.opaque_tys.insert(ItemEntry::new(new_url, name)),
286 ItemType::Static => self.statics.insert(ItemEntry::new(new_url, name)),
287 ItemType::Constant => self.constants.insert(ItemEntry::new(new_url, name)),
288 ItemType::ProcAttribute => {
289 self.attribute_macros.insert(ItemEntry::new(new_url, name))
291 ItemType::ProcDerive => self.derive_macros.insert(ItemEntry::new(new_url, name)),
292 ItemType::TraitAlias => self.trait_aliases.insert(ItemEntry::new(new_url, name)),
298 fn item_sections(&self) -> FxHashSet<ItemSection> {
299 let mut sections = FxHashSet::default();
301 if !self.structs.is_empty() {
302 sections.insert(ItemSection::Structs);
304 if !self.enums.is_empty() {
305 sections.insert(ItemSection::Enums);
307 if !self.unions.is_empty() {
308 sections.insert(ItemSection::Unions);
310 if !self.primitives.is_empty() {
311 sections.insert(ItemSection::PrimitiveTypes);
313 if !self.traits.is_empty() {
314 sections.insert(ItemSection::Traits);
316 if !self.macros.is_empty() {
317 sections.insert(ItemSection::Macros);
319 if !self.functions.is_empty() {
320 sections.insert(ItemSection::Functions);
322 if !self.typedefs.is_empty() {
323 sections.insert(ItemSection::TypeDefinitions);
325 if !self.opaque_tys.is_empty() {
326 sections.insert(ItemSection::OpaqueTypes);
328 if !self.statics.is_empty() {
329 sections.insert(ItemSection::Statics);
331 if !self.constants.is_empty() {
332 sections.insert(ItemSection::Constants);
334 if !self.attribute_macros.is_empty() {
335 sections.insert(ItemSection::AttributeMacros);
337 if !self.derive_macros.is_empty() {
338 sections.insert(ItemSection::DeriveMacros);
340 if !self.trait_aliases.is_empty() {
341 sections.insert(ItemSection::TraitAliases);
347 fn print(self, f: &mut Buffer) {
348 fn print_entries(f: &mut Buffer, e: &FxHashSet<ItemEntry>, kind: ItemSection) {
350 let mut e: Vec<&ItemEntry> = e.iter().collect();
354 "<h3 id=\"{id}\">{title}</h3><ul class=\"all-items\">",
360 write!(f, "<li>{}</li>", s.print());
363 f.write_str("</ul>");
367 f.write_str("<h1>List of all items</h1>");
368 // Note: print_entries does not escape the title, because we know the current set of titles
369 // doesn't require escaping.
370 print_entries(f, &self.structs, ItemSection::Structs);
371 print_entries(f, &self.enums, ItemSection::Enums);
372 print_entries(f, &self.unions, ItemSection::Unions);
373 print_entries(f, &self.primitives, ItemSection::PrimitiveTypes);
374 print_entries(f, &self.traits, ItemSection::Traits);
375 print_entries(f, &self.macros, ItemSection::Macros);
376 print_entries(f, &self.attribute_macros, ItemSection::AttributeMacros);
377 print_entries(f, &self.derive_macros, ItemSection::DeriveMacros);
378 print_entries(f, &self.functions, ItemSection::Functions);
379 print_entries(f, &self.typedefs, ItemSection::TypeDefinitions);
380 print_entries(f, &self.trait_aliases, ItemSection::TraitAliases);
381 print_entries(f, &self.opaque_tys, ItemSection::OpaqueTypes);
382 print_entries(f, &self.statics, ItemSection::Statics);
383 print_entries(f, &self.constants, ItemSection::Constants);
387 fn scrape_examples_help(shared: &SharedContext<'_>) -> String {
388 let mut content = SCRAPE_EXAMPLES_HELP_MD.to_owned();
389 content.push_str(&format!(
390 "## More information\n\n\
391 If you want more information about this feature, please read the [corresponding chapter in the Rustdoc book]({}/rustdoc/scraped-examples.html).",
392 DOC_RUST_LANG_ORG_CHANNEL));
394 let mut ids = IdMap::default();
396 "<div class=\"main-heading\">\
397 <h1>About scraped examples</h1>\
404 error_codes: shared.codes,
405 edition: shared.edition(),
406 playground: &shared.playground,
407 heading_offset: HeadingOffset::H1
415 cx: &mut Context<'_>,
417 parent: Option<&clean::Item>,
418 heading_offset: HeadingOffset,
420 if let Some(ref name) = item.name {
421 info!("Documenting {}", name);
423 document_item_info(w, cx, item, parent);
424 if parent.is_none() {
425 document_full_collapsible(w, item, cx, heading_offset);
427 document_full(w, item, cx, heading_offset);
431 /// Render md_text as markdown.
434 cx: &mut Context<'_>,
436 links: Vec<RenderedLink>,
437 heading_offset: HeadingOffset,
441 "<div class=\"docblock\">{}</div>",
446 error_codes: cx.shared.codes,
447 edition: cx.shared.edition(),
448 playground: &cx.shared.playground,
455 /// Writes a documentation block containing only the first paragraph of the documentation. If the
456 /// docs are longer, a "Read more" link is appended to the end.
460 cx: &mut Context<'_>,
461 link: AssocItemLink<'_>,
462 parent: &clean::Item,
465 document_item_info(w, cx, item, Some(parent));
469 if let Some(s) = item.doc_value() {
470 let (mut summary_html, has_more_content) =
471 MarkdownSummaryLine(&s, &item.links(cx)).into_string_with_has_more_content();
473 if has_more_content {
474 let link = format!(r#" <a{}>Read more</a>"#, assoc_href_attr(item, link, cx));
476 if let Some(idx) = summary_html.rfind("</p>") {
477 summary_html.insert_str(idx, &link);
479 summary_html.push_str(&link);
483 write!(w, "<div class='docblock'>{}</div>", summary_html,);
487 fn document_full_collapsible(
490 cx: &mut Context<'_>,
491 heading_offset: HeadingOffset,
493 document_full_inner(w, item, cx, true, heading_offset);
499 cx: &mut Context<'_>,
500 heading_offset: HeadingOffset,
502 document_full_inner(w, item, cx, false, heading_offset);
505 fn document_full_inner(
508 cx: &mut Context<'_>,
509 is_collapsible: bool,
510 heading_offset: HeadingOffset,
512 if let Some(s) = item.collapsed_doc_value() {
513 debug!("Doc block: =====\n{}\n=====", s);
516 "<details class=\"toggle top-doc\" open>\
517 <summary class=\"hideme\">\
518 <span>Expand description</span>\
521 render_markdown(w, cx, &s, item.links(cx), heading_offset);
522 w.write_str("</details>");
524 render_markdown(w, cx, &s, item.links(cx), heading_offset);
528 let kind = match &*item.kind {
529 clean::ItemKind::StrippedItem(box kind) | kind => kind,
532 if let clean::ItemKind::FunctionItem(..) | clean::ItemKind::MethodItem(..) = kind {
533 render_call_locations(w, cx, item);
537 /// Add extra information about an item such as:
541 /// * Required features (through the `doc_cfg` feature)
542 fn document_item_info(
544 cx: &mut Context<'_>,
546 parent: Option<&clean::Item>,
548 let item_infos = short_item_info(item, cx, parent);
549 if !item_infos.is_empty() {
550 w.write_str("<span class=\"item-info\">");
551 for info in item_infos {
554 w.write_str("</span>");
558 fn portability(item: &clean::Item, parent: Option<&clean::Item>) -> Option<String> {
559 let cfg = match (&item.cfg, parent.and_then(|p| p.cfg.as_ref())) {
560 (Some(cfg), Some(parent_cfg)) => cfg.simplify_with(parent_cfg),
561 (cfg, _) => cfg.as_deref().cloned(),
565 "Portability {:?} {:?} (parent: {:?}) - {:?} = {:?}",
569 parent.and_then(|p| p.cfg.as_ref()),
573 Some(format!("<div class=\"stab portability\">{}</div>", cfg?.render_long_html()))
576 /// Render the stability, deprecation and portability information that is displayed at the top of
577 /// the item's documentation.
580 cx: &mut Context<'_>,
581 parent: Option<&clean::Item>,
583 let mut extra_info = vec![];
585 if let Some(depr @ Deprecation { note, since, is_since_rustc_version: _, suggestion: _ }) =
586 item.deprecation(cx.tcx())
588 // We display deprecation messages for #[deprecated], but only display
589 // the future-deprecation messages for rustc versions.
590 let mut message = if let Some(since) = since {
591 let since = since.as_str();
592 if !stability::deprecation_in_effect(&depr) {
594 String::from("Deprecating in a future Rust version")
596 format!("Deprecating in {}", Escape(since))
599 format!("Deprecated since {}", Escape(since))
602 String::from("Deprecated")
605 if let Some(note) = note {
606 let note = note.as_str();
607 let html = MarkdownItemInfo(note, &mut cx.id_map);
608 message.push_str(&format!(": {}", html.into_string()));
610 extra_info.push(format!(
611 "<div class=\"stab deprecated\">\
612 <span class=\"emoji\">👎</span>\
619 // Render unstable items. But don't render "rustc_private" crates (internal compiler crates).
620 // Those crates are permanently unstable so it makes no sense to render "unstable" everywhere.
621 if let Some((StabilityLevel::Unstable { reason: _, issue, .. }, feature)) = item
624 .filter(|stab| stab.feature != sym::rustc_private)
625 .map(|stab| (stab.level, stab.feature))
627 let mut message = "<span class=\"emoji\">🔬</span>\
628 <span>This is a nightly-only experimental API."
631 let mut feature = format!("<code>{}</code>", Escape(feature.as_str()));
632 if let (Some(url), Some(issue)) = (&cx.shared.issue_tracker_base_url, issue) {
633 feature.push_str(&format!(
634 " <a href=\"{url}{issue}\">#{issue}</a>",
640 message.push_str(&format!(" ({})</span>", feature));
642 extra_info.push(format!("<div class=\"stab unstable\">{}</div>", message));
645 if let Some(portability) = portability(item, parent) {
646 extra_info.push(portability);
652 // Render the list of items inside one of the sections "Trait Implementations",
653 // "Auto Trait Implementations," "Blanket Trait Implementations" (on struct/enum pages).
654 pub(crate) fn render_impls(
655 cx: &mut Context<'_>,
658 containing_item: &clean::Item,
659 toggle_open_by_default: bool,
662 let mut rendered_impls = impls
665 let did = i.trait_did().unwrap();
666 let provided_trait_methods = i.inner_impl().provided_trait_methods(tcx);
667 let assoc_link = AssocItemLink::GotoSource(did.into(), &provided_trait_methods);
668 let mut buffer = if w.is_for_html() { Buffer::html() } else { Buffer::new() };
678 ImplRenderingParameters {
680 show_default_items: true,
681 show_non_assoc_items: true,
682 toggle_open_by_default,
687 .collect::<Vec<_>>();
688 rendered_impls.sort();
689 w.write_str(&rendered_impls.join(""));
692 /// Build a (possibly empty) `href` attribute (a key-value pair) for the given associated item.
693 fn assoc_href_attr(it: &clean::Item, link: AssocItemLink<'_>, cx: &Context<'_>) -> String {
694 let name = it.name.unwrap();
695 let item_type = it.type_();
697 let href = match link {
698 AssocItemLink::Anchor(Some(ref id)) => Some(format!("#{}", id)),
699 AssocItemLink::Anchor(None) => Some(format!("#{}.{}", item_type, name)),
700 AssocItemLink::GotoSource(did, provided_methods) => {
701 // We're creating a link from the implementation of an associated item to its
702 // declaration in the trait declaration.
703 let item_type = match item_type {
704 // For historical but not technical reasons, the item type of methods in
705 // trait declarations depends on whether the method is required (`TyMethod`) or
706 // provided (`Method`).
707 ItemType::Method | ItemType::TyMethod => {
708 if provided_methods.contains(&name) {
714 // For associated types and constants, no such distinction exists.
715 item_type => item_type,
718 match href(did.expect_def_id(), cx) {
719 Ok((url, ..)) => Some(format!("{}#{}.{}", url, item_type, name)),
720 // The link is broken since it points to an external crate that wasn't documented.
721 // Do not create any link in such case. This is better than falling back to a
722 // dummy anchor like `#{item_type}.{name}` representing the `id` of *this* impl item
723 // (that used to happen in older versions). Indeed, in most cases this dummy would
724 // coincide with the `id`. However, it would not always do so.
725 // In general, this dummy would be incorrect:
726 // If the type with the trait impl also had an inherent impl with an assoc. item of
727 // the *same* name as this impl item, the dummy would link to that one even though
728 // those two items are distinct!
729 // In this scenario, the actual `id` of this impl item would be
730 // `#{item_type}.{name}-{n}` for some number `n` (a disambiguator).
731 Err(HrefError::DocumentationNotBuilt) => None,
732 Err(_) => Some(format!("#{}.{}", item_type, name)),
737 // If there is no `href` for the reason explained above, simply do not render it which is valid:
738 // https://html.spec.whatwg.org/multipage/links.html#links-created-by-a-and-area-elements
739 href.map(|href| format!(" href=\"{}\"", href)).unwrap_or_default()
746 default: Option<&clean::ConstantKind>,
747 link: AssocItemLink<'_>,
754 "{extra}{vis}const <a{href} class=\"constant\">{name}</a>: {ty}",
756 vis = visibility_print_with_space(it.visibility(tcx), it.item_id, cx),
757 href = assoc_href_attr(it, link, cx),
758 name = it.name.as_ref().unwrap(),
761 if let Some(default) = default {
764 // FIXME: `.value()` uses `clean::utils::format_integer_with_underscore_sep` under the
765 // hood which adds noisy underscores and a type suffix to number literals.
766 // This hurts readability in this context especially when more complex expressions
767 // are involved and it doesn't add much of value.
768 // Find a way to print constants here without all that jazz.
769 write!(w, "{}", Escape(&default.value(tcx).unwrap_or_else(|| default.expr(tcx))));
776 generics: &clean::Generics,
777 bounds: &[clean::GenericBound],
778 default: Option<&clean::Type>,
779 link: AssocItemLink<'_>,
785 "{indent}type <a{href} class=\"associatedtype\">{name}</a>{generics}",
786 indent = " ".repeat(indent),
787 href = assoc_href_attr(it, link, cx),
788 name = it.name.as_ref().unwrap(),
789 generics = generics.print(cx),
791 if !bounds.is_empty() {
792 write!(w, ": {}", print_generic_bounds(bounds, cx))
794 write!(w, "{}", print_where_clause(generics, cx, indent, Ending::NoNewline));
795 if let Some(default) = default {
796 write!(w, " = {}", default.print(cx))
805 link: AssocItemLink<'_>,
807 cx: &mut Context<'_>,
808 render_mode: RenderMode,
811 let header = meth.fn_header(tcx).expect("Trying to get header from a non-function item");
812 let name = meth.name.as_ref().unwrap();
813 let vis = visibility_print_with_space(meth.visibility(tcx), meth.item_id, cx).to_string();
814 // FIXME: Once https://github.com/rust-lang/rust/issues/67792 is implemented, we can remove
816 let constness = match render_mode {
817 RenderMode::Normal => {
818 print_constness_with_space(&header.constness, meth.const_stability(tcx))
820 RenderMode::ForDeref { .. } => "",
822 let asyncness = header.asyncness.print_with_space();
823 let unsafety = header.unsafety.print_with_space();
824 let defaultness = print_default_space(meth.is_default());
825 let abi = print_abi_with_space(header.abi).to_string();
826 let href = assoc_href_attr(meth, link, cx);
828 // NOTE: `{:#}` does not print HTML formatting, `{}` does. So `g.print` can't be reused between the length calculation and `write!`.
829 let generics_len = format!("{:#}", g.print(cx)).len();
830 let mut header_len = "fn ".len()
837 + name.as_str().len()
840 let notable_traits = d.output.as_return().and_then(|output| notable_traits_button(output, cx));
842 let (indent, indent_str, end_newline) = if parent == ItemType::Trait {
844 let indent_str = " ";
845 render_attributes_in_pre(w, meth, indent_str);
846 (4, indent_str, Ending::NoNewline)
848 render_attributes_in_code(w, meth);
849 (0, "", Ending::Newline)
851 w.reserve(header_len + "<a href=\"\" class=\"fn\">{".len() + "</a>".len());
854 "{indent}{vis}{constness}{asyncness}{unsafety}{defaultness}{abi}fn <a{href} class=\"fn\">{name}</a>\
855 {generics}{decl}{notable_traits}{where_clause}",
858 constness = constness,
859 asyncness = asyncness,
861 defaultness = defaultness,
865 generics = g.print(cx),
866 decl = d.full_print(header_len, indent, cx),
867 notable_traits = notable_traits.unwrap_or_default(),
868 where_clause = print_where_clause(g, cx, indent, end_newline),
872 /// Writes a span containing the versions at which an item became stable and/or const-stable. For
873 /// example, if the item became stable at 1.0.0, and const-stable at 1.45.0, this function would
874 /// write a span containing "1.0.0 (const: 1.45.0)".
876 /// Returns `true` if a stability annotation was rendered.
878 /// Stability and const-stability are considered separately. If the item is unstable, no version
879 /// will be written. If the item is const-unstable, "const: unstable" will be appended to the
880 /// span, with a link to the tracking issue if present. If an item's stability or const-stability
881 /// version matches the version of its enclosing item, that version will be omitted.
883 /// Note that it is possible for an unstable function to be const-stable. In that case, the span
884 /// will include the const-stable version, but no stable version will be emitted, as a natural
885 /// consequence of the above rules.
886 fn render_stability_since_raw_with_extra(
889 const_stability: Option<ConstStability>,
890 containing_ver: Option<Symbol>,
891 containing_const_ver: Option<Symbol>,
894 let stable_version = ver.filter(|inner| !inner.is_empty() && Some(*inner) != containing_ver);
896 let mut title = String::new();
897 let mut stability = String::new();
899 if let Some(ver) = stable_version {
900 stability.push_str(ver.as_str());
901 title.push_str(&format!("Stable since Rust version {}", ver));
904 let const_title_and_stability = match const_stability {
905 Some(ConstStability { level: StabilityLevel::Stable { since, .. }, .. })
906 if Some(since) != containing_const_ver =>
908 Some((format!("const since {}", since), format!("const: {}", since)))
910 Some(ConstStability { level: StabilityLevel::Unstable { issue, .. }, feature, .. }) => {
911 let unstable = if let Some(n) = issue {
913 r#"<a href="https://github.com/rust-lang/rust/issues/{}" title="Tracking issue for {}">unstable</a>"#,
917 String::from("unstable")
920 Some((String::from("const unstable"), format!("const: {}", unstable)))
925 if let Some((const_title, const_stability)) = const_title_and_stability {
926 if !title.is_empty() {
927 title.push_str(&format!(", {}", const_title));
929 title.push_str(&const_title);
932 if !stability.is_empty() {
933 stability.push_str(&format!(" ({})", const_stability));
935 stability.push_str(&const_stability);
939 if !stability.is_empty() {
940 write!(w, r#"<span class="since{extra_class}" title="{title}">{stability}</span>"#);
943 !stability.is_empty()
947 fn render_stability_since_raw(
950 const_stability: Option<ConstStability>,
951 containing_ver: Option<Symbol>,
952 containing_const_ver: Option<Symbol>,
954 render_stability_since_raw_with_extra(
959 containing_const_ver,
964 fn render_assoc_item(
967 link: AssocItemLink<'_>,
969 cx: &mut Context<'_>,
970 render_mode: RenderMode,
973 clean::StrippedItem(..) => {}
974 clean::TyMethodItem(m) => {
975 assoc_method(w, item, &m.generics, &m.decl, link, parent, cx, render_mode)
977 clean::MethodItem(m, _) => {
978 assoc_method(w, item, &m.generics, &m.decl, link, parent, cx, render_mode)
980 kind @ (clean::TyAssocConstItem(ty) | clean::AssocConstItem(ty, _)) => assoc_const(
985 clean::TyAssocConstItem(_) => None,
986 clean::AssocConstItem(_, default) => Some(default),
990 if parent == ItemType::Trait { " " } else { "" },
993 clean::TyAssocTypeItem(ref generics, ref bounds) => assoc_type(
1000 if parent == ItemType::Trait { 4 } else { 0 },
1003 clean::AssocTypeItem(ref ty, ref bounds) => assoc_type(
1008 Some(ty.item_type.as_ref().unwrap_or(&ty.type_)),
1010 if parent == ItemType::Trait { 4 } else { 0 },
1013 _ => panic!("render_assoc_item called on non-associated-item"),
1017 const ALLOWED_ATTRIBUTES: &[Symbol] =
1018 &[sym::export_name, sym::link_section, sym::no_mangle, sym::repr, sym::non_exhaustive];
1020 fn attributes(it: &clean::Item) -> Vec<String> {
1024 .filter_map(|attr| {
1025 if ALLOWED_ATTRIBUTES.contains(&attr.name_or_empty()) {
1027 pprust::attribute_to_string(attr)
1028 .replace("\\\n", "")
1039 // When an attribute is rendered inside a `<pre>` tag, it is formatted using
1040 // a whitespace prefix and newline.
1041 fn render_attributes_in_pre(w: &mut Buffer, it: &clean::Item, prefix: &str) {
1042 for a in attributes(it) {
1043 writeln!(w, "{}{}", prefix, a);
1047 // When an attribute is rendered inside a <code> tag, it is formatted using
1048 // a div to produce a newline after it.
1049 fn render_attributes_in_code(w: &mut Buffer, it: &clean::Item) {
1050 for a in attributes(it) {
1051 write!(w, "<div class=\"code-attribute\">{}</div>", a);
1055 #[derive(Copy, Clone)]
1056 enum AssocItemLink<'a> {
1057 Anchor(Option<&'a str>),
1058 GotoSource(ItemId, &'a FxHashSet<Symbol>),
1061 impl<'a> AssocItemLink<'a> {
1062 fn anchor(&self, id: &'a str) -> Self {
1064 AssocItemLink::Anchor(_) => AssocItemLink::Anchor(Some(id)),
1065 ref other => *other,
1070 fn write_impl_section_heading(w: &mut Buffer, title: &str, id: &str) {
1073 "<h2 id=\"{id}\" class=\"small-section-header\">\
1075 <a href=\"#{id}\" class=\"anchor\">§</a>\
1080 pub(crate) fn render_all_impls(
1082 cx: &mut Context<'_>,
1083 containing_item: &clean::Item,
1085 synthetic: &[&Impl],
1086 blanket_impl: &[&Impl],
1088 let mut impls = Buffer::empty_from(w);
1089 render_impls(cx, &mut impls, concrete, containing_item, true);
1090 let impls = impls.into_inner();
1091 if !impls.is_empty() {
1092 write_impl_section_heading(w, "Trait Implementations", "trait-implementations");
1093 write!(w, "<div id=\"trait-implementations-list\">{}</div>", impls);
1096 if !synthetic.is_empty() {
1097 write_impl_section_heading(w, "Auto Trait Implementations", "synthetic-implementations");
1098 w.write_str("<div id=\"synthetic-implementations-list\">");
1099 render_impls(cx, w, synthetic, containing_item, false);
1100 w.write_str("</div>");
1103 if !blanket_impl.is_empty() {
1104 write_impl_section_heading(w, "Blanket Implementations", "blanket-implementations");
1105 w.write_str("<div id=\"blanket-implementations-list\">");
1106 render_impls(cx, w, blanket_impl, containing_item, false);
1107 w.write_str("</div>");
1111 fn render_assoc_items(
1113 cx: &mut Context<'_>,
1114 containing_item: &clean::Item,
1116 what: AssocItemRender<'_>,
1118 let mut derefs = DefIdSet::default();
1120 render_assoc_items_inner(w, cx, containing_item, it, what, &mut derefs)
1123 fn render_assoc_items_inner(
1125 cx: &mut Context<'_>,
1126 containing_item: &clean::Item,
1128 what: AssocItemRender<'_>,
1129 derefs: &mut DefIdSet,
1131 info!("Documenting associated items of {:?}", containing_item.name);
1132 let shared = Rc::clone(&cx.shared);
1133 let cache = &shared.cache;
1134 let Some(v) = cache.impls.get(&it) else { return };
1135 let (non_trait, traits): (Vec<_>, _) = v.iter().partition(|i| i.inner_impl().trait_.is_none());
1136 if !non_trait.is_empty() {
1137 let mut tmp_buf = Buffer::empty_from(w);
1138 let (render_mode, id) = match what {
1139 AssocItemRender::All => {
1140 write_impl_section_heading(&mut tmp_buf, "Implementations", "implementations");
1141 (RenderMode::Normal, "implementations-list".to_owned())
1143 AssocItemRender::DerefFor { trait_, type_, deref_mut_ } => {
1145 cx.derive_id(small_url_encode(format!("deref-methods-{:#}", type_.print(cx))));
1146 if let Some(def_id) = type_.def_id(cx.cache()) {
1147 cx.deref_id_map.insert(def_id, id.clone());
1149 write_impl_section_heading(
1152 "<span>Methods from {trait_}<Target = {type_}></span>",
1153 trait_ = trait_.print(cx),
1154 type_ = type_.print(cx),
1158 (RenderMode::ForDeref { mut_: deref_mut_ }, cx.derive_id(id))
1161 let mut impls_buf = Buffer::empty_from(w);
1162 for i in &non_trait {
1168 AssocItemLink::Anchor(None),
1172 ImplRenderingParameters {
1173 show_def_docs: true,
1174 show_default_items: true,
1175 show_non_assoc_items: true,
1176 toggle_open_by_default: true,
1180 if !impls_buf.is_empty() {
1181 w.push_buffer(tmp_buf);
1182 write!(w, "<div id=\"{}\">", id);
1183 w.push_buffer(impls_buf);
1184 w.write_str("</div>");
1188 if !traits.is_empty() {
1190 traits.iter().find(|t| t.trait_did() == cx.tcx().lang_items().deref_trait());
1191 if let Some(impl_) = deref_impl {
1193 traits.iter().any(|t| t.trait_did() == cx.tcx().lang_items().deref_mut_trait());
1194 render_deref_methods(w, cx, impl_, containing_item, has_deref_mut, derefs);
1197 // If we were already one level into rendering deref methods, we don't want to render
1198 // anything after recursing into any further deref methods above.
1199 if let AssocItemRender::DerefFor { .. } = what {
1203 let (synthetic, concrete): (Vec<&Impl>, Vec<&Impl>) =
1204 traits.into_iter().partition(|t| t.inner_impl().kind.is_auto());
1205 let (blanket_impl, concrete): (Vec<&Impl>, _) =
1206 concrete.into_iter().partition(|t| t.inner_impl().kind.is_blanket());
1208 render_all_impls(w, cx, containing_item, &concrete, &synthetic, &blanket_impl);
1212 fn render_deref_methods(
1214 cx: &mut Context<'_>,
1216 container_item: &clean::Item,
1218 derefs: &mut DefIdSet,
1220 let cache = cx.cache();
1221 let deref_type = impl_.inner_impl().trait_.as_ref().unwrap();
1222 let (target, real_target) = impl_
1226 .find_map(|item| match *item.kind {
1227 clean::AssocTypeItem(box ref t, _) => Some(match *t {
1228 clean::Typedef { item_type: Some(ref type_), .. } => (type_, &t.type_),
1229 _ => (&t.type_, &t.type_),
1233 .expect("Expected associated type binding");
1234 debug!("Render deref methods for {:#?}, target {:#?}", impl_.inner_impl().for_, target);
1236 AssocItemRender::DerefFor { trait_: deref_type, type_: real_target, deref_mut_: deref_mut };
1237 if let Some(did) = target.def_id(cache) {
1238 if let Some(type_did) = impl_.inner_impl().for_.def_id(cache) {
1239 // `impl Deref<Target = S> for S`
1240 if did == type_did || !derefs.insert(did) {
1241 // Avoid infinite cycles
1245 render_assoc_items_inner(w, cx, container_item, did, what, derefs);
1246 } else if let Some(prim) = target.primitive_type() {
1247 if let Some(&did) = cache.primitive_locations.get(&prim) {
1248 render_assoc_items_inner(w, cx, container_item, did, what, derefs);
1253 fn should_render_item(item: &clean::Item, deref_mut_: bool, tcx: TyCtxt<'_>) -> bool {
1254 let self_type_opt = match *item.kind {
1255 clean::MethodItem(ref method, _) => method.decl.self_type(),
1256 clean::TyMethodItem(ref method) => method.decl.self_type(),
1260 if let Some(self_ty) = self_type_opt {
1261 let (by_mut_ref, by_box, by_value) = match self_ty {
1262 SelfTy::SelfBorrowed(_, mutability)
1263 | SelfTy::SelfExplicit(clean::BorrowedRef { mutability, .. }) => {
1264 (mutability == Mutability::Mut, false, false)
1266 SelfTy::SelfExplicit(clean::Type::Path { path }) => {
1267 (false, Some(path.def_id()) == tcx.lang_items().owned_box(), false)
1269 SelfTy::SelfValue => (false, false, true),
1270 _ => (false, false, false),
1273 (deref_mut_ || !by_mut_ref) && !by_box && !by_value
1279 pub(crate) fn notable_traits_button(ty: &clean::Type, cx: &mut Context<'_>) -> Option<String> {
1280 let mut has_notable_trait = false;
1282 let did = ty.def_id(cx.cache())?;
1284 // Box has pass-through impls for Read, Write, Iterator, and Future when the
1285 // boxed type implements one of those. We don't want to treat every Box return
1286 // as being notably an Iterator (etc), though, so we exempt it. Pin has the same
1287 // issue, with a pass-through impl for Future.
1288 if Some(did) == cx.tcx().lang_items().owned_box()
1289 || Some(did) == cx.tcx().lang_items().pin_type()
1294 if let Some(impls) = cx.cache().impls.get(&did) {
1296 let impl_ = i.inner_impl();
1297 if !impl_.for_.without_borrowed_ref().is_same(ty.without_borrowed_ref(), cx.cache()) {
1298 // Two different types might have the same did,
1299 // without actually being the same.
1302 if let Some(trait_) = &impl_.trait_ {
1303 let trait_did = trait_.def_id();
1305 if cx.cache().traits.get(&trait_did).map_or(false, |t| t.is_notable_trait(cx.tcx()))
1307 has_notable_trait = true;
1313 if has_notable_trait {
1314 cx.types_with_notable_traits.insert(ty.clone());
1316 " <a href=\"#\" class=\"notable-traits\" data-ty=\"{ty}\">ⓘ</a>",
1317 ty = Escape(&format!("{:#}", ty.print(cx))),
1324 fn notable_traits_decl(ty: &clean::Type, cx: &Context<'_>) -> (String, String) {
1325 let mut out = Buffer::html();
1327 let did = ty.def_id(cx.cache()).expect("notable_traits_button already checked this");
1329 let impls = cx.cache().impls.get(&did).expect("notable_traits_button already checked this");
1332 let impl_ = i.inner_impl();
1333 if !impl_.for_.without_borrowed_ref().is_same(ty.without_borrowed_ref(), cx.cache()) {
1334 // Two different types might have the same did,
1335 // without actually being the same.
1338 if let Some(trait_) = &impl_.trait_ {
1339 let trait_did = trait_.def_id();
1341 if cx.cache().traits.get(&trait_did).map_or(false, |t| t.is_notable_trait(cx.tcx())) {
1345 "<h3>Notable traits for <code>{}</code></h3>\
1347 impl_.for_.print(cx)
1351 //use the "where" class here to make it small
1354 "<span class=\"where fmt-newline\">{}</span>",
1355 impl_.print(false, cx)
1357 for it in &impl_.items {
1358 if let clean::AssocTypeItem(ref tydef, ref _bounds) = *it.kind {
1359 out.push_str("<span class=\"where fmt-newline\"> ");
1360 let empty_set = FxHashSet::default();
1361 let src_link = AssocItemLink::GotoSource(trait_did.into(), &empty_set);
1366 &[], // intentionally leaving out bounds
1372 out.push_str(";</span>");
1379 write!(&mut out, "</code></pre>",);
1382 (format!("{:#}", ty.print(cx)), out.into_inner())
1385 pub(crate) fn notable_traits_json<'a>(
1386 tys: impl Iterator<Item = &'a clean::Type>,
1389 let mut mp: Vec<(String, String)> = tys.map(|ty| notable_traits_decl(ty, cx)).collect();
1390 mp.sort_by(|(name1, _html1), (name2, _html2)| name1.cmp(name2));
1391 struct NotableTraitsMap(Vec<(String, String)>);
1392 impl Serialize for NotableTraitsMap {
1393 fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
1397 let mut map = serializer.serialize_map(Some(self.0.len()))?;
1398 for item in &self.0 {
1399 map.serialize_entry(&item.0, &item.1)?;
1404 serde_json::to_string(&NotableTraitsMap(mp))
1405 .expect("serialize (string, string) -> json object cannot fail")
1408 #[derive(Clone, Copy, Debug)]
1409 struct ImplRenderingParameters {
1410 show_def_docs: bool,
1411 show_default_items: bool,
1412 /// Whether or not to show methods.
1413 show_non_assoc_items: bool,
1414 toggle_open_by_default: bool,
1419 cx: &mut Context<'_>,
1421 parent: &clean::Item,
1422 link: AssocItemLink<'_>,
1423 render_mode: RenderMode,
1424 use_absolute: Option<bool>,
1426 rendering_params: ImplRenderingParameters,
1428 let shared = Rc::clone(&cx.shared);
1429 let cache = &shared.cache;
1430 let traits = &cache.traits;
1431 let trait_ = i.trait_did().map(|did| &traits[&did]);
1432 let mut close_tags = String::new();
1434 // For trait implementations, the `interesting` output contains all methods that have doc
1435 // comments, and the `boring` output contains all methods that do not. The distinction is
1436 // used to allow hiding the boring methods.
1437 // `containing_item` is used for rendering stability info. If the parent is a trait impl,
1438 // `containing_item` will the grandparent, since trait impls can't have stability attached.
1440 boring: &mut Buffer,
1441 interesting: &mut Buffer,
1442 cx: &mut Context<'_>,
1444 parent: &clean::Item,
1445 containing_item: &clean::Item,
1446 link: AssocItemLink<'_>,
1447 render_mode: RenderMode,
1448 is_default_item: bool,
1449 trait_: Option<&clean::Trait>,
1450 rendering_params: ImplRenderingParameters,
1452 let item_type = item.type_();
1453 let name = item.name.as_ref().unwrap();
1455 let render_method_item = rendering_params.show_non_assoc_items
1456 && match render_mode {
1457 RenderMode::Normal => true,
1458 RenderMode::ForDeref { mut_: deref_mut_ } => {
1459 should_render_item(item, deref_mut_, cx.tcx())
1463 let in_trait_class = if trait_.is_some() { " trait-impl" } else { "" };
1465 let mut doc_buffer = Buffer::empty_from(boring);
1466 let mut info_buffer = Buffer::empty_from(boring);
1467 let mut short_documented = true;
1469 if render_method_item {
1470 if !is_default_item {
1471 if let Some(t) = trait_ {
1472 // The trait item may have been stripped so we might not
1473 // find any documentation or stability for it.
1474 if let Some(it) = t.items.iter().find(|i| i.name == item.name) {
1475 // We need the stability of the item from the trait
1476 // because impls can't have a stability.
1477 if item.doc_value().is_some() {
1478 document_item_info(&mut info_buffer, cx, it, Some(parent));
1479 document_full(&mut doc_buffer, item, cx, HeadingOffset::H5);
1480 short_documented = false;
1482 // In case the item isn't documented,
1483 // provide short documentation from the trait.
1490 rendering_params.show_def_docs,
1495 document_item_info(&mut info_buffer, cx, item, Some(parent));
1496 if rendering_params.show_def_docs {
1497 document_full(&mut doc_buffer, item, cx, HeadingOffset::H5);
1498 short_documented = false;
1508 rendering_params.show_def_docs,
1512 let w = if short_documented && trait_.is_some() { interesting } else { boring };
1514 let toggled = !doc_buffer.is_empty();
1516 let method_toggle_class = if item_type.is_method() { " method-toggle" } else { "" };
1517 write!(w, "<details class=\"toggle{}\" open><summary>", method_toggle_class);
1520 clean::MethodItem(..) | clean::TyMethodItem(_) => {
1521 // Only render when the method is not static or we allow static methods
1522 if render_method_item {
1523 let id = cx.derive_id(format!("{}.{}", item_type, name));
1524 let source_id = trait_
1525 .and_then(|trait_| {
1526 trait_.items.iter().find(|item| {
1527 item.name.map(|n| n.as_str().eq(name.as_str())).unwrap_or(false)
1530 .map(|item| format!("{}.{}", item.type_(), name));
1531 write!(w, "<section id=\"{}\" class=\"{}{}\">", id, item_type, in_trait_class,);
1532 render_rightside(w, cx, item, containing_item, render_mode);
1533 if trait_.is_some() {
1534 // Anchors are only used on trait impls.
1535 write!(w, "<a href=\"#{}\" class=\"anchor\">§</a>", id);
1537 w.write_str("<h4 class=\"code-header\">");
1541 link.anchor(source_id.as_ref().unwrap_or(&id)),
1546 w.write_str("</h4>");
1547 w.write_str("</section>");
1550 kind @ (clean::TyAssocConstItem(ty) | clean::AssocConstItem(ty, _)) => {
1551 let source_id = format!("{}.{}", item_type, name);
1552 let id = cx.derive_id(source_id.clone());
1553 write!(w, "<section id=\"{}\" class=\"{}{}\">", id, item_type, in_trait_class);
1554 render_rightside(w, cx, item, containing_item, render_mode);
1555 if trait_.is_some() {
1556 // Anchors are only used on trait impls.
1557 write!(w, "<a href=\"#{}\" class=\"anchor\">§</a>", id);
1559 w.write_str("<h4 class=\"code-header\">");
1565 clean::TyAssocConstItem(_) => None,
1566 clean::AssocConstItem(_, default) => Some(default),
1567 _ => unreachable!(),
1569 link.anchor(if trait_.is_some() { &source_id } else { &id }),
1573 w.write_str("</h4>");
1574 w.write_str("</section>");
1576 clean::TyAssocTypeItem(generics, bounds) => {
1577 let source_id = format!("{}.{}", item_type, name);
1578 let id = cx.derive_id(source_id.clone());
1579 write!(w, "<section id=\"{}\" class=\"{}{}\">", id, item_type, in_trait_class);
1580 if trait_.is_some() {
1581 // Anchors are only used on trait impls.
1582 write!(w, "<a href=\"#{}\" class=\"anchor\">§</a>", id);
1584 w.write_str("<h4 class=\"code-header\">");
1591 link.anchor(if trait_.is_some() { &source_id } else { &id }),
1595 w.write_str("</h4>");
1596 w.write_str("</section>");
1598 clean::AssocTypeItem(tydef, _bounds) => {
1599 let source_id = format!("{}.{}", item_type, name);
1600 let id = cx.derive_id(source_id.clone());
1601 write!(w, "<section id=\"{}\" class=\"{}{}\">", id, item_type, in_trait_class);
1602 if trait_.is_some() {
1603 // Anchors are only used on trait impls.
1604 write!(w, "<a href=\"#{}\" class=\"anchor\">§</a>", id);
1606 w.write_str("<h4 class=\"code-header\">");
1611 &[], // intentionally leaving out bounds
1612 Some(tydef.item_type.as_ref().unwrap_or(&tydef.type_)),
1613 link.anchor(if trait_.is_some() { &source_id } else { &id }),
1617 w.write_str("</h4>");
1618 w.write_str("</section>");
1620 clean::StrippedItem(..) => return,
1621 _ => panic!("can't make docs for trait item with name {:?}", item.name),
1624 w.push_buffer(info_buffer);
1626 w.write_str("</summary>");
1627 w.push_buffer(doc_buffer);
1628 w.push_str("</details>");
1632 let mut impl_items = Buffer::empty_from(w);
1633 let mut default_impl_items = Buffer::empty_from(w);
1635 for trait_item in &i.inner_impl().items {
1637 &mut default_impl_items,
1641 if trait_.is_some() { &i.impl_item } else { parent },
1651 fn render_default_items(
1652 boring: &mut Buffer,
1653 interesting: &mut Buffer,
1654 cx: &mut Context<'_>,
1657 parent: &clean::Item,
1658 containing_item: &clean::Item,
1659 render_mode: RenderMode,
1660 rendering_params: ImplRenderingParameters,
1662 for trait_item in &t.items {
1663 // Skip over any default trait items that are impossible to call
1664 // (e.g. if it has a `Self: Sized` bound on an unsized type).
1665 if let Some(impl_def_id) = parent.item_id.as_def_id()
1666 && let Some(trait_item_def_id) = trait_item.item_id.as_def_id()
1667 && cx.tcx().is_impossible_method((impl_def_id, trait_item_def_id))
1672 let n = trait_item.name;
1673 if i.items.iter().any(|m| m.name == n) {
1676 let did = i.trait_.as_ref().unwrap().def_id();
1677 let provided_methods = i.provided_trait_methods(cx.tcx());
1678 let assoc_link = AssocItemLink::GotoSource(did.into(), &provided_methods);
1696 // If we've implemented a trait, then also emit documentation for all
1697 // default items which weren't overridden in the implementation block.
1698 // We don't emit documentation for default items if they appear in the
1699 // Implementations on Foreign Types or Implementors sections.
1700 if rendering_params.show_default_items {
1701 if let Some(t) = trait_ {
1702 render_default_items(
1703 &mut default_impl_items,
1715 if render_mode == RenderMode::Normal {
1716 let toggled = !(impl_items.is_empty() && default_impl_items.is_empty());
1718 close_tags.insert_str(0, "</details>");
1721 "<details class=\"toggle implementors-toggle\"{}>",
1722 if rendering_params.toggle_open_by_default { " open" } else { "" }
1724 write!(w, "<summary>")
1726 render_impl_summary(
1732 rendering_params.show_def_docs,
1737 write!(w, "</summary>")
1740 if let Some(ref dox) = i.impl_item.collapsed_doc_value() {
1741 if trait_.is_none() && i.inner_impl().items.is_empty() {
1743 "<div class=\"item-info\">\
1744 <div class=\"stab empty-impl\">This impl block contains no items.</div>
1750 "<div class=\"docblock\">{}</div>",
1753 links: &i.impl_item.links(cx),
1754 ids: &mut cx.id_map,
1755 error_codes: cx.shared.codes,
1756 edition: cx.shared.edition(),
1757 playground: &cx.shared.playground,
1758 heading_offset: HeadingOffset::H4
1764 if !default_impl_items.is_empty() || !impl_items.is_empty() {
1765 w.write_str("<div class=\"impl-items\">");
1766 w.push_buffer(default_impl_items);
1767 w.push_buffer(impl_items);
1768 close_tags.insert_str(0, "</div>");
1770 w.write_str(&close_tags);
1773 // Render the items that appear on the right side of methods, impls, and
1774 // associated types. For example "1.0.0 (const: 1.39.0) · source".
1775 fn render_rightside(
1779 containing_item: &clean::Item,
1780 render_mode: RenderMode,
1784 // FIXME: Once https://github.com/rust-lang/rust/issues/67792 is implemented, we can remove
1786 let (const_stability, const_stable_since) = match render_mode {
1787 RenderMode::Normal => (item.const_stability(tcx), containing_item.const_stable_since(tcx)),
1788 RenderMode::ForDeref { .. } => (None, None),
1790 let src_href = cx.src_href(item);
1791 let has_src_ref = src_href.is_some();
1793 let mut rightside = Buffer::new();
1794 let has_stability = render_stability_since_raw_with_extra(
1796 item.stable_since(tcx),
1798 containing_item.stable_since(tcx),
1800 if has_src_ref { "" } else { " rightside" },
1802 if let Some(l) = src_href {
1804 write!(rightside, " · <a class=\"srclink\" href=\"{}\">source</a>", l)
1806 write!(rightside, "<a class=\"srclink rightside\" href=\"{}\">source</a>", l)
1809 if has_stability && has_src_ref {
1810 write!(w, "<span class=\"rightside\">{}</span>", rightside.into_inner());
1812 w.push_buffer(rightside);
1816 pub(crate) fn render_impl_summary(
1818 cx: &mut Context<'_>,
1820 parent: &clean::Item,
1821 containing_item: &clean::Item,
1822 show_def_docs: bool,
1823 use_absolute: Option<bool>,
1824 // This argument is used to reference same type with different paths to avoid duplication
1825 // in documentation pages for trait with automatic implementations like "Send" and "Sync".
1828 let inner_impl = i.inner_impl();
1829 let id = cx.derive_id(get_id_for_impl(&inner_impl.for_, inner_impl.trait_.as_ref(), cx));
1830 let aliases = if aliases.is_empty() {
1833 format!(" data-aliases=\"{}\"", aliases.join(","))
1835 write!(w, "<section id=\"{}\" class=\"impl\"{}>", id, aliases);
1836 render_rightside(w, cx, &i.impl_item, containing_item, RenderMode::Normal);
1837 write!(w, "<a href=\"#{}\" class=\"anchor\">§</a>", id);
1838 write!(w, "<h3 class=\"code-header\">");
1840 if let Some(use_absolute) = use_absolute {
1841 write!(w, "{}", inner_impl.print(use_absolute, cx));
1843 for it in &inner_impl.items {
1844 if let clean::AssocTypeItem(ref tydef, ref _bounds) = *it.kind {
1845 w.write_str("<span class=\"where fmt-newline\"> ");
1850 &[], // intentionally leaving out bounds
1852 AssocItemLink::Anchor(None),
1856 w.write_str(";</span>");
1861 write!(w, "{}", inner_impl.print(false, cx));
1865 let is_trait = inner_impl.trait_.is_some();
1867 if let Some(portability) = portability(&i.impl_item, Some(parent)) {
1868 write!(w, "<span class=\"item-info\">{}</span>", portability);
1872 w.write_str("</section>");
1875 fn print_sidebar(cx: &Context<'_>, it: &clean::Item, buffer: &mut Buffer) {
1878 || it.is_primitive()
1886 "<h2 class=\"location\"><a href=\"#\">{}{}</a></h2>",
1888 clean::ModuleItem(..) =>
1896 it.name.as_ref().unwrap()
1900 buffer.write_str("<div class=\"sidebar-elems\">");
1902 write!(buffer, "<ul class=\"block\">");
1903 if let Some(ref version) = cx.cache().crate_version {
1904 write!(buffer, "<li class=\"version\">Version {}</li>", Escape(version));
1906 write!(buffer, "<li><a id=\"all-types\" href=\"all.html\">All Items</a></li>");
1907 buffer.write_str("</ul>");
1911 clean::StructItem(ref s) => sidebar_struct(cx, buffer, it, s),
1912 clean::TraitItem(ref t) => sidebar_trait(cx, buffer, it, t),
1913 clean::PrimitiveItem(_) => sidebar_primitive(cx, buffer, it),
1914 clean::UnionItem(ref u) => sidebar_union(cx, buffer, it, u),
1915 clean::EnumItem(ref e) => sidebar_enum(cx, buffer, it, e),
1916 clean::TypedefItem(_) => sidebar_typedef(cx, buffer, it),
1917 clean::ModuleItem(ref m) => sidebar_module(buffer, &m.items),
1918 clean::ForeignTypeItem => sidebar_foreign_type(cx, buffer, it),
1922 // The sidebar is designed to display sibling functions, modules and
1923 // other miscellaneous information. since there are lots of sibling
1924 // items (and that causes quadratic growth in large modules),
1925 // we refactor common parts into a shared JavaScript file per module.
1926 // still, we don't move everything into JS because we want to preserve
1927 // as much HTML as possible in order to allow non-JS-enabled browsers
1928 // to navigate the documentation (though slightly inefficiently).
1931 let path: String = cx.current.iter().map(|s| s.as_str()).intersperse("::").collect();
1933 write!(buffer, "<h2><a href=\"index.html\">In {}</a></h2>", path);
1936 // Closes sidebar-elems div.
1937 buffer.write_str("</div>");
1940 fn get_next_url(used_links: &mut FxHashSet<String>, url: String) -> String {
1941 if used_links.insert(url.clone()) {
1945 while !used_links.insert(format!("{}-{}", url, add)) {
1948 format!("{}-{}", url, add)
1951 struct SidebarLink {
1956 impl fmt::Display for SidebarLink {
1957 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1958 write!(f, "<a href=\"#{}\">{}</a>", self.url, self.name)
1962 impl PartialEq for SidebarLink {
1963 fn eq(&self, other: &Self) -> bool {
1964 self.url == other.url
1968 impl Eq for SidebarLink {}
1970 impl PartialOrd for SidebarLink {
1971 fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
1972 Some(self.cmp(other))
1976 impl Ord for SidebarLink {
1977 fn cmp(&self, other: &Self) -> std::cmp::Ordering {
1978 self.url.cmp(&other.url)
1985 used_links: &mut FxHashSet<String>,
1988 ) -> Vec<SidebarLink> {
1991 .filter_map(|item| match item.name {
1992 Some(name) if !name.is_empty() && item.is_method() => {
1993 if !for_deref || should_render_item(item, deref_mut, tcx) {
1996 url: get_next_url(used_links, format!("{}.{}", ItemType::Method, name)),
2004 .collect::<Vec<_>>()
2007 fn get_associated_constants(
2009 used_links: &mut FxHashSet<String>,
2010 ) -> Vec<SidebarLink> {
2013 .filter_map(|item| match item.name {
2014 Some(name) if !name.is_empty() && item.is_associated_const() => Some(SidebarLink {
2016 url: get_next_url(used_links, format!("{}.{}", ItemType::AssocConst, name)),
2020 .collect::<Vec<_>>()
2023 // The point is to url encode any potential character from a type with genericity.
2024 fn small_url_encode(s: String) -> String {
2025 let mut st = String::new();
2026 let mut last_match = 0;
2027 for (idx, c) in s.char_indices() {
2028 let escaped = match c {
2044 st += &s[last_match..idx];
2046 // NOTE: we only expect single byte characters here - which is fine as long as we
2047 // only match single byte characters
2048 last_match = idx + 1;
2051 if last_match != 0 {
2052 st += &s[last_match..];
2059 pub(crate) fn sidebar_render_assoc_items(
2063 concrete: Vec<&Impl>,
2064 synthetic: Vec<&Impl>,
2065 blanket_impl: Vec<&Impl>,
2067 let format_impls = |impls: Vec<&Impl>, id_map: &mut IdMap| {
2068 let mut links = FxHashSet::default();
2073 let trait_ = it.inner_impl().trait_.as_ref()?;
2075 id_map.derive(get_id_for_impl(&it.inner_impl().for_, Some(trait_), cx));
2077 let i_display = format!("{:#}", trait_.print(cx));
2078 let out = Escape(&i_display);
2079 let prefix = match it.inner_impl().polarity {
2080 ty::ImplPolarity::Positive | ty::ImplPolarity::Reservation => "",
2081 ty::ImplPolarity::Negative => "!",
2083 let generated = format!("<a href=\"#{}\">{}{}</a>", encoded, prefix, out);
2084 if links.insert(generated.clone()) { Some(generated) } else { None }
2086 .collect::<Vec<String>>();
2091 let concrete_format = format_impls(concrete, id_map);
2092 let synthetic_format = format_impls(synthetic, id_map);
2093 let blanket_format = format_impls(blanket_impl, id_map);
2095 if !concrete_format.is_empty() {
2096 print_sidebar_block(
2098 "trait-implementations",
2099 "Trait Implementations",
2100 concrete_format.iter(),
2104 if !synthetic_format.is_empty() {
2105 print_sidebar_block(
2107 "synthetic-implementations",
2108 "Auto Trait Implementations",
2109 synthetic_format.iter(),
2113 if !blanket_format.is_empty() {
2114 print_sidebar_block(
2116 "blanket-implementations",
2117 "Blanket Implementations",
2118 blanket_format.iter(),
2123 fn sidebar_assoc_items(cx: &Context<'_>, out: &mut Buffer, it: &clean::Item) {
2124 let did = it.item_id.expect_def_id();
2125 let cache = cx.cache();
2127 if let Some(v) = cache.impls.get(&did) {
2128 let mut used_links = FxHashSet::default();
2129 let mut id_map = IdMap::new();
2132 let used_links_bor = &mut used_links;
2133 let mut assoc_consts = v
2135 .filter(|i| i.inner_impl().trait_.is_none())
2136 .flat_map(|i| get_associated_constants(i.inner_impl(), used_links_bor))
2137 .collect::<Vec<_>>();
2138 if !assoc_consts.is_empty() {
2139 // We want links' order to be reproducible so we don't use unstable sort.
2140 assoc_consts.sort();
2142 print_sidebar_block(
2145 "Associated Constants",
2146 assoc_consts.iter(),
2151 .filter(|i| i.inner_impl().trait_.is_none())
2152 .flat_map(|i| get_methods(i.inner_impl(), false, used_links_bor, false, cx.tcx()))
2153 .collect::<Vec<_>>();
2154 if !methods.is_empty() {
2155 // We want links' order to be reproducible so we don't use unstable sort.
2158 print_sidebar_block(out, "implementations", "Methods", methods.iter());
2162 if v.iter().any(|i| i.inner_impl().trait_.is_some()) {
2163 if let Some(impl_) =
2164 v.iter().find(|i| i.trait_did() == cx.tcx().lang_items().deref_trait())
2166 let mut derefs = DefIdSet::default();
2168 sidebar_deref_methods(cx, out, impl_, v, &mut derefs, &mut used_links);
2171 let (synthetic, concrete): (Vec<&Impl>, Vec<&Impl>) =
2172 v.iter().partition::<Vec<_>, _>(|i| i.inner_impl().kind.is_auto());
2173 let (blanket_impl, concrete): (Vec<&Impl>, Vec<&Impl>) =
2174 concrete.into_iter().partition::<Vec<_>, _>(|i| i.inner_impl().kind.is_blanket());
2176 sidebar_render_assoc_items(cx, out, &mut id_map, concrete, synthetic, blanket_impl);
2181 fn sidebar_deref_methods(
2186 derefs: &mut DefIdSet,
2187 used_links: &mut FxHashSet<String>,
2191 debug!("found Deref: {:?}", impl_);
2192 if let Some((target, real_target)) =
2193 impl_.inner_impl().items.iter().find_map(|item| match *item.kind {
2194 clean::AssocTypeItem(box ref t, _) => Some(match *t {
2195 clean::Typedef { item_type: Some(ref type_), .. } => (type_, &t.type_),
2196 _ => (&t.type_, &t.type_),
2201 debug!("found target, real_target: {:?} {:?}", target, real_target);
2202 if let Some(did) = target.def_id(c) {
2203 if let Some(type_did) = impl_.inner_impl().for_.def_id(c) {
2204 // `impl Deref<Target = S> for S`
2205 if did == type_did || !derefs.insert(did) {
2206 // Avoid infinite cycles
2211 let deref_mut = v.iter().any(|i| i.trait_did() == cx.tcx().lang_items().deref_mut_trait());
2212 let inner_impl = target
2215 target.primitive_type().and_then(|prim| c.primitive_locations.get(&prim).cloned())
2217 .and_then(|did| c.impls.get(&did));
2218 if let Some(impls) = inner_impl {
2219 debug!("found inner_impl: {:?}", impls);
2222 .filter(|i| i.inner_impl().trait_.is_none())
2223 .flat_map(|i| get_methods(i.inner_impl(), true, used_links, deref_mut, cx.tcx()))
2224 .collect::<Vec<_>>();
2225 if !ret.is_empty() {
2226 let id = if let Some(target_def_id) = real_target.def_id(c) {
2227 cx.deref_id_map.get(&target_def_id).expect("Deref section without derived id")
2231 let title = format!(
2232 "Methods from {}<Target={}>",
2233 Escape(&format!("{:#}", impl_.inner_impl().trait_.as_ref().unwrap().print(cx))),
2234 Escape(&format!("{:#}", real_target.print(cx))),
2236 // We want links' order to be reproducible so we don't use unstable sort.
2238 print_sidebar_block(out, id, &title, ret.iter());
2242 // Recurse into any further impls that might exist for `target`
2243 if let Some(target_did) = target.def_id(c) {
2244 if let Some(target_impls) = c.impls.get(&target_did) {
2245 if let Some(target_deref_impl) = target_impls.iter().find(|i| {
2249 .map(|t| Some(t.def_id()) == cx.tcx().lang_items().deref_trait())
2252 sidebar_deref_methods(
2266 fn sidebar_struct(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, s: &clean::Struct) {
2267 let mut sidebar = Buffer::new();
2268 let fields = get_struct_fields_name(&s.fields);
2270 if !fields.is_empty() {
2273 print_sidebar_block(&mut sidebar, "fields", "Fields", fields.iter());
2275 Some(CtorKind::Fn) => print_sidebar_title(&mut sidebar, "fields", "Tuple Fields"),
2276 Some(CtorKind::Const) => {}
2280 sidebar_assoc_items(cx, &mut sidebar, it);
2282 if !sidebar.is_empty() {
2283 write!(buf, "<section>{}</section>", sidebar.into_inner());
2287 fn get_id_for_impl(for_: &clean::Type, trait_: Option<&clean::Path>, cx: &Context<'_>) -> String {
2289 Some(t) => small_url_encode(format!("impl-{:#}-for-{:#}", t.print(cx), for_.print(cx))),
2290 None => small_url_encode(format!("impl-{:#}", for_.print(cx))),
2294 fn extract_for_impl_name(item: &clean::Item, cx: &Context<'_>) -> Option<(String, String)> {
2296 clean::ItemKind::ImplItem(ref i) => {
2297 i.trait_.as_ref().map(|trait_| {
2298 // Alternative format produces no URLs,
2299 // so this parameter does nothing.
2300 (format!("{:#}", i.for_.print(cx)), get_id_for_impl(&i.for_, Some(trait_), cx))
2307 fn print_sidebar_title(buf: &mut Buffer, id: &str, title: &str) {
2308 write!(buf, "<h3><a href=\"#{}\">{}</a></h3>", id, title);
2311 fn print_sidebar_block(
2315 items: impl Iterator<Item = impl fmt::Display>,
2317 print_sidebar_title(buf, id, title);
2318 buf.push_str("<ul class=\"block\">");
2320 write!(buf, "<li>{}</li>", item);
2322 buf.push_str("</ul>");
2325 fn sidebar_trait(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, t: &clean::Trait) {
2326 buf.write_str("<section>");
2328 fn print_sidebar_section(
2330 items: &[clean::Item],
2333 filter: impl Fn(&clean::Item) -> bool,
2334 mapper: impl Fn(&str) -> String,
2336 let mut items: Vec<&str> = items
2338 .filter_map(|m| match m.name {
2339 Some(ref name) if filter(m) => Some(name.as_str()),
2342 .collect::<Vec<_>>();
2344 if !items.is_empty() {
2345 items.sort_unstable();
2346 print_sidebar_block(out, id, title, items.into_iter().map(mapper));
2350 print_sidebar_section(
2353 "required-associated-types",
2354 "Required Associated Types",
2355 |m| m.is_ty_associated_type(),
2356 |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::AssocType),
2359 print_sidebar_section(
2362 "provided-associated-types",
2363 "Provided Associated Types",
2364 |m| m.is_associated_type(),
2365 |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::AssocType),
2368 print_sidebar_section(
2371 "required-associated-consts",
2372 "Required Associated Constants",
2373 |m| m.is_ty_associated_const(),
2374 |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::AssocConst),
2377 print_sidebar_section(
2380 "provided-associated-consts",
2381 "Provided Associated Constants",
2382 |m| m.is_associated_const(),
2383 |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::AssocConst),
2386 print_sidebar_section(
2391 |m| m.is_ty_method(),
2392 |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::TyMethod),
2395 print_sidebar_section(
2401 |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::Method),
2404 if let Some(implementors) = cx.cache().implementors.get(&it.item_id.expect_def_id()) {
2405 let mut res = implementors
2407 .filter(|i| !i.is_on_local_type(cx))
2408 .filter_map(|i| extract_for_impl_name(&i.impl_item, cx))
2409 .collect::<Vec<_>>();
2411 if !res.is_empty() {
2413 print_sidebar_block(
2416 "Implementations on Foreign Types",
2417 res.iter().map(|(name, id)| format!("<a href=\"#{}\">{}</a>", id, Escape(name))),
2422 sidebar_assoc_items(cx, buf, it);
2424 print_sidebar_title(buf, "implementors", "Implementors");
2425 if t.is_auto(cx.tcx()) {
2426 print_sidebar_title(buf, "synthetic-implementors", "Auto Implementors");
2429 buf.push_str("</section>")
2432 /// Returns the list of implementations for the primitive reference type, filtering out any
2433 /// implementations that are on concrete or partially generic types, only keeping implementations
2434 /// of the form `impl<T> Trait for &T`.
2435 pub(crate) fn get_filtered_impls_for_reference<'a>(
2436 shared: &'a Rc<SharedContext<'_>>,
2438 ) -> (Vec<&'a Impl>, Vec<&'a Impl>, Vec<&'a Impl>) {
2439 let def_id = it.item_id.expect_def_id();
2440 // If the reference primitive is somehow not defined, exit early.
2441 let Some(v) = shared.cache.impls.get(&def_id) else { return (Vec::new(), Vec::new(), Vec::new()) };
2442 // Since there is no "direct implementation" on the reference primitive type, we filter out
2443 // every implementation which isn't a trait implementation.
2444 let traits = v.iter().filter(|i| i.inner_impl().trait_.is_some());
2445 let (synthetic, concrete): (Vec<&Impl>, Vec<&Impl>) =
2446 traits.partition(|t| t.inner_impl().kind.is_auto());
2448 let (blanket_impl, concrete): (Vec<&Impl>, _) =
2449 concrete.into_iter().partition(|t| t.inner_impl().kind.is_blanket());
2450 // Now we keep only references over full generic types.
2451 let concrete: Vec<_> = concrete
2453 .filter(|t| match t.inner_impl().for_ {
2454 clean::Type::BorrowedRef { ref type_, .. } => type_.is_full_generic(),
2459 (concrete, synthetic, blanket_impl)
2462 fn sidebar_primitive(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item) {
2463 let mut sidebar = Buffer::new();
2465 if it.name.map(|n| n.as_str() != "reference").unwrap_or(false) {
2466 sidebar_assoc_items(cx, &mut sidebar, it);
2468 let shared = Rc::clone(&cx.shared);
2469 let (concrete, synthetic, blanket_impl) = get_filtered_impls_for_reference(&shared, it);
2471 sidebar_render_assoc_items(
2481 if !sidebar.is_empty() {
2482 write!(buf, "<section>{}</section>", sidebar.into_inner());
2486 fn sidebar_typedef(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item) {
2487 let mut sidebar = Buffer::new();
2488 sidebar_assoc_items(cx, &mut sidebar, it);
2490 if !sidebar.is_empty() {
2491 write!(buf, "<section>{}</section>", sidebar.into_inner());
2495 fn get_struct_fields_name(fields: &[clean::Item]) -> Vec<String> {
2496 let mut fields = fields
2498 .filter(|f| matches!(*f.kind, clean::StructFieldItem(..)))
2500 f.name.map(|name| format!("<a href=\"#structfield.{name}\">{name}</a>", name = name))
2502 .collect::<Vec<_>>();
2507 fn sidebar_union(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, u: &clean::Union) {
2508 let mut sidebar = Buffer::new();
2509 let fields = get_struct_fields_name(&u.fields);
2511 if !fields.is_empty() {
2512 print_sidebar_block(&mut sidebar, "fields", "Fields", fields.iter());
2515 sidebar_assoc_items(cx, &mut sidebar, it);
2517 if !sidebar.is_empty() {
2518 write!(buf, "<section>{}</section>", sidebar.into_inner());
2522 fn sidebar_enum(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, e: &clean::Enum) {
2523 let mut sidebar = Buffer::new();
2525 let mut variants = e
2530 .map(|name| format!("<a href=\"#variant.{name}\">{name}</a>", name = name))
2532 .collect::<Vec<_>>();
2533 if !variants.is_empty() {
2534 variants.sort_unstable();
2535 print_sidebar_block(&mut sidebar, "variants", "Variants", variants.iter());
2538 sidebar_assoc_items(cx, &mut sidebar, it);
2540 if !sidebar.is_empty() {
2541 write!(buf, "<section>{}</section>", sidebar.into_inner());
2545 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
2546 pub(crate) enum ItemSection {
2565 AssociatedConstants,
2575 const ALL: &'static [Self] = {
2577 // NOTE: The order here affects the order in the UI.
2597 AssociatedConstants,
2607 fn id(self) -> &'static str {
2609 Self::Reexports => "reexports",
2610 Self::Modules => "modules",
2611 Self::Structs => "structs",
2612 Self::Unions => "unions",
2613 Self::Enums => "enums",
2614 Self::Functions => "functions",
2615 Self::TypeDefinitions => "types",
2616 Self::Statics => "statics",
2617 Self::Constants => "constants",
2618 Self::Traits => "traits",
2619 Self::Implementations => "impls",
2620 Self::TypeMethods => "tymethods",
2621 Self::Methods => "methods",
2622 Self::StructFields => "fields",
2623 Self::Variants => "variants",
2624 Self::Macros => "macros",
2625 Self::PrimitiveTypes => "primitives",
2626 Self::AssociatedTypes => "associated-types",
2627 Self::AssociatedConstants => "associated-consts",
2628 Self::ForeignTypes => "foreign-types",
2629 Self::Keywords => "keywords",
2630 Self::OpaqueTypes => "opaque-types",
2631 Self::AttributeMacros => "attributes",
2632 Self::DeriveMacros => "derives",
2633 Self::TraitAliases => "trait-aliases",
2637 fn name(self) -> &'static str {
2639 Self::Reexports => "Re-exports",
2640 Self::Modules => "Modules",
2641 Self::Structs => "Structs",
2642 Self::Unions => "Unions",
2643 Self::Enums => "Enums",
2644 Self::Functions => "Functions",
2645 Self::TypeDefinitions => "Type Definitions",
2646 Self::Statics => "Statics",
2647 Self::Constants => "Constants",
2648 Self::Traits => "Traits",
2649 Self::Implementations => "Implementations",
2650 Self::TypeMethods => "Type Methods",
2651 Self::Methods => "Methods",
2652 Self::StructFields => "Struct Fields",
2653 Self::Variants => "Variants",
2654 Self::Macros => "Macros",
2655 Self::PrimitiveTypes => "Primitive Types",
2656 Self::AssociatedTypes => "Associated Types",
2657 Self::AssociatedConstants => "Associated Constants",
2658 Self::ForeignTypes => "Foreign Types",
2659 Self::Keywords => "Keywords",
2660 Self::OpaqueTypes => "Opaque Types",
2661 Self::AttributeMacros => "Attribute Macros",
2662 Self::DeriveMacros => "Derive Macros",
2663 Self::TraitAliases => "Trait Aliases",
2668 fn item_ty_to_section(ty: ItemType) -> ItemSection {
2670 ItemType::ExternCrate | ItemType::Import => ItemSection::Reexports,
2671 ItemType::Module => ItemSection::Modules,
2672 ItemType::Struct => ItemSection::Structs,
2673 ItemType::Union => ItemSection::Unions,
2674 ItemType::Enum => ItemSection::Enums,
2675 ItemType::Function => ItemSection::Functions,
2676 ItemType::Typedef => ItemSection::TypeDefinitions,
2677 ItemType::Static => ItemSection::Statics,
2678 ItemType::Constant => ItemSection::Constants,
2679 ItemType::Trait => ItemSection::Traits,
2680 ItemType::Impl => ItemSection::Implementations,
2681 ItemType::TyMethod => ItemSection::TypeMethods,
2682 ItemType::Method => ItemSection::Methods,
2683 ItemType::StructField => ItemSection::StructFields,
2684 ItemType::Variant => ItemSection::Variants,
2685 ItemType::Macro => ItemSection::Macros,
2686 ItemType::Primitive => ItemSection::PrimitiveTypes,
2687 ItemType::AssocType => ItemSection::AssociatedTypes,
2688 ItemType::AssocConst => ItemSection::AssociatedConstants,
2689 ItemType::ForeignType => ItemSection::ForeignTypes,
2690 ItemType::Keyword => ItemSection::Keywords,
2691 ItemType::OpaqueTy => ItemSection::OpaqueTypes,
2692 ItemType::ProcAttribute => ItemSection::AttributeMacros,
2693 ItemType::ProcDerive => ItemSection::DeriveMacros,
2694 ItemType::TraitAlias => ItemSection::TraitAliases,
2698 pub(crate) fn sidebar_module_like(buf: &mut Buffer, item_sections_in_use: FxHashSet<ItemSection>) {
2699 use std::fmt::Write as _;
2701 let mut sidebar = String::new();
2703 for &sec in ItemSection::ALL.iter().filter(|sec| item_sections_in_use.contains(sec)) {
2704 let _ = write!(sidebar, "<li><a href=\"#{}\">{}</a></li>", sec.id(), sec.name());
2707 if !sidebar.is_empty() {
2711 <ul class=\"block\">{}</ul>\
2718 fn sidebar_module(buf: &mut Buffer, items: &[clean::Item]) {
2719 let item_sections_in_use: FxHashSet<_> = items
2726 if let clean::ImportItem(ref i) = *it.kind &&
2727 let clean::ImportKind::Simple(s) = i.kind { Some(s) } else { None }
2731 .map(|it| item_ty_to_section(it.type_()))
2734 sidebar_module_like(buf, item_sections_in_use);
2737 fn sidebar_foreign_type(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item) {
2738 let mut sidebar = Buffer::new();
2739 sidebar_assoc_items(cx, &mut sidebar, it);
2741 if !sidebar.is_empty() {
2742 write!(buf, "<section>{}</section>", sidebar.into_inner());
2746 pub(crate) const BASIC_KEYWORDS: &str = "rust, rustlang, rust-lang";
2748 /// Returns a list of all paths used in the type.
2749 /// This is used to help deduplicate imported impls
2750 /// for reexported types. If any of the contained
2751 /// types are re-exported, we don't use the corresponding
2752 /// entry from the js file, as inlining will have already
2753 /// picked up the impl
2754 fn collect_paths_for_type(first_ty: clean::Type, cache: &Cache) -> Vec<String> {
2755 let mut out = Vec::new();
2756 let mut visited = FxHashSet::default();
2757 let mut work = VecDeque::new();
2759 let mut process_path = |did: DefId| {
2760 let get_extern = || cache.external_paths.get(&did).map(|s| &s.0);
2761 let fqp = cache.exact_paths.get(&did).or_else(get_extern);
2763 if let Some(path) = fqp {
2764 out.push(join_with_double_colon(&path));
2768 work.push_back(first_ty);
2770 while let Some(ty) = work.pop_front() {
2771 if !visited.insert(ty.clone()) {
2776 clean::Type::Path { path } => process_path(path.def_id()),
2777 clean::Type::Tuple(tys) => {
2778 work.extend(tys.into_iter());
2780 clean::Type::Slice(ty) => {
2781 work.push_back(*ty);
2783 clean::Type::Array(ty, _) => {
2784 work.push_back(*ty);
2786 clean::Type::RawPointer(_, ty) => {
2787 work.push_back(*ty);
2789 clean::Type::BorrowedRef { type_, .. } => {
2790 work.push_back(*type_);
2792 clean::Type::QPath(box clean::QPathData { self_type, trait_, .. }) => {
2793 work.push_back(self_type);
2794 process_path(trait_.def_id());
2802 const MAX_FULL_EXAMPLES: usize = 5;
2803 const NUM_VISIBLE_LINES: usize = 10;
2805 /// Generates the HTML for example call locations generated via the --scrape-examples flag.
2806 fn render_call_locations(w: &mut Buffer, cx: &mut Context<'_>, item: &clean::Item) {
2808 let def_id = item.item_id.expect_def_id();
2809 let key = tcx.def_path_hash(def_id);
2810 let Some(call_locations) = cx.shared.call_locations.get(&key) else { return };
2812 // Generate a unique ID so users can link to this section for a given method
2813 let id = cx.id_map.derive("scraped-examples");
2816 "<div class=\"docblock scraped-example-list\">\
2819 <a href=\"#{id}\">Examples found in repository</a>\
2820 <a class=\"scrape-help\" href=\"{root_path}scrape-examples-help.html\">?</a>\
2822 root_path = cx.root_path(),
2826 // Create a URL to a particular location in a reverse-dependency's source file
2827 let link_to_loc = |call_data: &CallData, loc: &CallLocation| -> (String, String) {
2828 let (line_lo, line_hi) = loc.call_expr.line_span;
2829 let (anchor, title) = if line_lo == line_hi {
2830 ((line_lo + 1).to_string(), format!("line {}", line_lo + 1))
2833 format!("{}-{}", line_lo + 1, line_hi + 1),
2834 format!("lines {}-{}", line_lo + 1, line_hi + 1),
2837 let url = format!("{}{}#{}", cx.root_path(), call_data.url, anchor);
2841 // Generate the HTML for a single example, being the title and code block
2842 let write_example = |w: &mut Buffer, (path, call_data): (&PathBuf, &CallData)| -> bool {
2843 let contents = match fs::read_to_string(&path) {
2844 Ok(contents) => contents,
2846 let span = item.span(tcx).map_or(rustc_span::DUMMY_SP, |span| span.inner());
2848 .span_err(span, &format!("failed to read file {}: {}", path.display(), err));
2853 // To reduce file sizes, we only want to embed the source code needed to understand the example, not
2854 // the entire file. So we find the smallest byte range that covers all items enclosing examples.
2855 assert!(!call_data.locations.is_empty());
2857 call_data.locations.iter().min_by_key(|loc| loc.enclosing_item.byte_span.0).unwrap();
2858 let byte_min = min_loc.enclosing_item.byte_span.0;
2859 let line_min = min_loc.enclosing_item.line_span.0;
2861 call_data.locations.iter().max_by_key(|loc| loc.enclosing_item.byte_span.1).unwrap();
2862 let byte_max = max_loc.enclosing_item.byte_span.1;
2863 let line_max = max_loc.enclosing_item.line_span.1;
2865 // The output code is limited to that byte range.
2866 let contents_subset = &contents[(byte_min as usize)..(byte_max as usize)];
2868 // The call locations need to be updated to reflect that the size of the program has changed.
2869 // Specifically, the ranges are all subtracted by `byte_min` since that's the new zero point.
2870 let (mut byte_ranges, line_ranges): (Vec<_>, Vec<_>) = call_data
2874 let (byte_lo, byte_hi) = loc.call_ident.byte_span;
2875 let (line_lo, line_hi) = loc.call_expr.line_span;
2876 let byte_range = (byte_lo - byte_min, byte_hi - byte_min);
2878 let line_range = (line_lo - line_min, line_hi - line_min);
2879 let (line_url, line_title) = link_to_loc(call_data, loc);
2881 (byte_range, (line_range, line_url, line_title))
2885 let (_, init_url, init_title) = &line_ranges[0];
2886 let needs_expansion = line_max - line_min > NUM_VISIBLE_LINES;
2887 let locations_encoded = serde_json::to_string(&line_ranges).unwrap();
2891 "<div class=\"scraped-example {expanded_cls}\" data-locs=\"{locations}\">\
2892 <div class=\"scraped-example-title\">\
2893 {name} (<a href=\"{url}\">{title}</a>)\
2895 <div class=\"code-wrapper\">",
2896 expanded_cls = if needs_expansion { "" } else { "expanded" },
2897 name = call_data.display_name,
2900 // The locations are encoded as a data attribute, so they can be read
2901 // later by the JS for interactions.
2902 locations = Escape(&locations_encoded)
2905 if line_ranges.len() > 1 {
2906 write!(w, r#"<button class="prev">≺</button> <button class="next">≻</button>"#);
2909 // Look for the example file in the source map if it exists, otherwise return a dummy span
2910 let file_span = (|| {
2911 let source_map = tcx.sess.source_map();
2912 let crate_src = tcx.sess.local_crate_source_file()?;
2913 let abs_crate_src = crate_src.canonicalize().ok()?;
2914 let crate_root = abs_crate_src.parent()?.parent()?;
2915 let rel_path = path.strip_prefix(crate_root).ok()?;
2916 let files = source_map.files();
2917 let file = files.iter().find(|file| match &file.name {
2918 FileName::Real(RealFileName::LocalPath(other_path)) => rel_path == other_path,
2921 Some(rustc_span::Span::with_root_ctxt(
2922 file.start_pos + BytePos(byte_min),
2923 file.start_pos + BytePos(byte_max),
2926 .unwrap_or(rustc_span::DUMMY_SP);
2928 let mut decoration_info = FxHashMap::default();
2929 decoration_info.insert("highlight focus", vec![byte_ranges.remove(0)]);
2930 decoration_info.insert("highlight", byte_ranges);
2938 highlight::DecorationInfo(decoration_info),
2939 sources::SourceContext::Embedded { offset: line_min, needs_expansion },
2941 write!(w, "</div></div>");
2946 // The call locations are output in sequence, so that sequence needs to be determined.
2947 // Ideally the most "relevant" examples would be shown first, but there's no general algorithm
2948 // for determining relevance. We instead proxy relevance with the following heuristics:
2949 // 1. Code written to be an example is better than code not written to be an example, e.g.
2950 // a snippet from examples/foo.rs is better than src/lib.rs. We don't know the Cargo
2951 // directory structure in Rustdoc, so we proxy this by prioritizing code that comes from
2952 // a --crate-type bin.
2953 // 2. Smaller examples are better than large examples. So we prioritize snippets that have
2954 // the smallest number of lines in their enclosing item.
2955 // 3. Finally we sort by the displayed file name, which is arbitrary but prevents the
2956 // ordering of examples from randomly changing between Rustdoc invocations.
2957 let ordered_locations = {
2958 fn sort_criterion<'a>(
2959 (_, call_data): &(&PathBuf, &'a CallData),
2960 ) -> (bool, u32, &'a String) {
2961 // Use the first location because that's what the user will see initially
2962 let (lo, hi) = call_data.locations[0].enclosing_item.byte_span;
2963 (!call_data.is_bin, hi - lo, &call_data.display_name)
2966 let mut locs = call_locations.iter().collect::<Vec<_>>();
2967 locs.sort_by_key(sort_criterion);
2971 let mut it = ordered_locations.into_iter().peekable();
2973 // An example may fail to write if its source can't be read for some reason, so this method
2974 // continues iterating until a write succeeds
2975 let write_and_skip_failure = |w: &mut Buffer, it: &mut Peekable<_>| {
2976 while let Some(example) = it.next() {
2977 if write_example(&mut *w, example) {
2983 // Write just one example that's visible by default in the method's description.
2984 write_and_skip_failure(w, &mut it);
2986 // Then add the remaining examples in a hidden section.
2987 if it.peek().is_some() {
2990 "<details class=\"toggle more-examples-toggle\">\
2991 <summary class=\"hideme\">\
2992 <span>More examples</span>\
2994 <div class=\"hide-more\">Hide additional examples</div>\
2995 <div class=\"more-scraped-examples\">\
2996 <div class=\"toggle-line\"><div class=\"toggle-line-inner\"></div></div>"
2999 // Only generate inline code for MAX_FULL_EXAMPLES number of examples. Otherwise we could
3000 // make the page arbitrarily huge!
3001 for _ in 0..MAX_FULL_EXAMPLES {
3002 write_and_skip_failure(w, &mut it);
3005 // For the remaining examples, generate a <ul> containing links to the source files.
3006 if it.peek().is_some() {
3007 write!(w, r#"<div class="example-links">Additional examples can be found in:<br><ul>"#);
3008 it.for_each(|(_, call_data)| {
3009 let (url, _) = link_to_loc(call_data, &call_data.locations[0]);
3012 r#"<li><a href="{url}">{name}</a></li>"#,
3014 name = call_data.display_name
3017 write!(w, "</ul></div>");
3020 write!(w, "</div></details>");
3023 write!(w, "</div>");