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;
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: String,
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 class=\"fqn\">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 class=\"fqn\">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 = MarkdownSummaryLine(&s, &item.links(cx)).into_string();
472 if s.contains('\n') {
473 let link = format!(r#" <a{}>Read more</a>"#, assoc_href_attr(item, link, cx));
475 if let Some(idx) = summary_html.rfind("</p>") {
476 summary_html.insert_str(idx, &link);
478 summary_html.push_str(&link);
482 write!(w, "<div class='docblock'>{}</div>", summary_html,);
486 fn document_full_collapsible(
489 cx: &mut Context<'_>,
490 heading_offset: HeadingOffset,
492 document_full_inner(w, item, cx, true, heading_offset);
498 cx: &mut Context<'_>,
499 heading_offset: HeadingOffset,
501 document_full_inner(w, item, cx, false, heading_offset);
504 fn document_full_inner(
507 cx: &mut Context<'_>,
508 is_collapsible: bool,
509 heading_offset: HeadingOffset,
511 if let Some(s) = item.collapsed_doc_value() {
512 debug!("Doc block: =====\n{}\n=====", s);
515 "<details class=\"rustdoc-toggle top-doc\" open>\
516 <summary class=\"hideme\">\
517 <span>Expand description</span>\
520 render_markdown(w, cx, &s, item.links(cx), heading_offset);
521 w.write_str("</details>");
523 render_markdown(w, cx, &s, item.links(cx), heading_offset);
527 let kind = match &*item.kind {
528 clean::ItemKind::StrippedItem(box kind) | kind => kind,
531 if let clean::ItemKind::FunctionItem(..) | clean::ItemKind::MethodItem(..) = kind {
532 render_call_locations(w, cx, item);
536 /// Add extra information about an item such as:
540 /// * Required features (through the `doc_cfg` feature)
541 fn document_item_info(
543 cx: &mut Context<'_>,
545 parent: Option<&clean::Item>,
547 let item_infos = short_item_info(item, cx, parent);
548 if !item_infos.is_empty() {
549 w.write_str("<span class=\"item-info\">");
550 for info in item_infos {
553 w.write_str("</span>");
557 fn portability(item: &clean::Item, parent: Option<&clean::Item>) -> Option<String> {
558 let cfg = match (&item.cfg, parent.and_then(|p| p.cfg.as_ref())) {
559 (Some(cfg), Some(parent_cfg)) => cfg.simplify_with(parent_cfg),
560 (cfg, _) => cfg.as_deref().cloned(),
564 "Portability {:?} {:?} (parent: {:?}) - {:?} = {:?}",
568 parent.and_then(|p| p.cfg.as_ref()),
572 Some(format!("<div class=\"stab portability\">{}</div>", cfg?.render_long_html()))
575 /// Render the stability, deprecation and portability information that is displayed at the top of
576 /// the item's documentation.
579 cx: &mut Context<'_>,
580 parent: Option<&clean::Item>,
582 let mut extra_info = vec![];
584 if let Some(depr @ Deprecation { note, since, is_since_rustc_version: _, suggestion: _ }) =
585 item.deprecation(cx.tcx())
587 // We display deprecation messages for #[deprecated], but only display
588 // the future-deprecation messages for rustc versions.
589 let mut message = if let Some(since) = since {
590 let since = since.as_str();
591 if !stability::deprecation_in_effect(&depr) {
593 String::from("Deprecating in a future Rust version")
595 format!("Deprecating in {}", Escape(since))
598 format!("Deprecated since {}", Escape(since))
601 String::from("Deprecated")
604 if let Some(note) = note {
605 let note = note.as_str();
606 let html = MarkdownItemInfo(note, &mut cx.id_map);
607 message.push_str(&format!(": {}", html.into_string()));
609 extra_info.push(format!(
610 "<div class=\"stab deprecated\">\
611 <span class=\"emoji\">👎</span>\
618 // Render unstable items. But don't render "rustc_private" crates (internal compiler crates).
619 // Those crates are permanently unstable so it makes no sense to render "unstable" everywhere.
620 if let Some((StabilityLevel::Unstable { reason: _, issue, .. }, feature)) = item
623 .filter(|stab| stab.feature != sym::rustc_private)
624 .map(|stab| (stab.level, stab.feature))
626 let mut message = "<span class=\"emoji\">🔬</span>\
627 <span>This is a nightly-only experimental API."
630 let mut feature = format!("<code>{}</code>", Escape(feature.as_str()));
631 if let (Some(url), Some(issue)) = (&cx.shared.issue_tracker_base_url, issue) {
632 feature.push_str(&format!(
633 " <a href=\"{url}{issue}\">#{issue}</a>",
639 message.push_str(&format!(" ({})</span>", feature));
641 extra_info.push(format!("<div class=\"stab unstable\">{}</div>", message));
644 if let Some(portability) = portability(item, parent) {
645 extra_info.push(portability);
651 // Render the list of items inside one of the sections "Trait Implementations",
652 // "Auto Trait Implementations," "Blanket Trait Implementations" (on struct/enum pages).
653 pub(crate) fn render_impls(
654 cx: &mut Context<'_>,
657 containing_item: &clean::Item,
658 toggle_open_by_default: bool,
661 let mut rendered_impls = impls
664 let did = i.trait_did().unwrap();
665 let provided_trait_methods = i.inner_impl().provided_trait_methods(tcx);
666 let assoc_link = AssocItemLink::GotoSource(did.into(), &provided_trait_methods);
667 let mut buffer = if w.is_for_html() { Buffer::html() } else { Buffer::new() };
677 ImplRenderingParameters {
679 show_default_items: true,
680 show_non_assoc_items: true,
681 toggle_open_by_default,
686 .collect::<Vec<_>>();
687 rendered_impls.sort();
688 w.write_str(&rendered_impls.join(""));
691 /// Build a (possibly empty) `href` attribute (a key-value pair) for the given associated item.
692 fn assoc_href_attr(it: &clean::Item, link: AssocItemLink<'_>, cx: &Context<'_>) -> String {
693 let name = it.name.unwrap();
694 let item_type = it.type_();
696 let href = match link {
697 AssocItemLink::Anchor(Some(ref id)) => Some(format!("#{}", id)),
698 AssocItemLink::Anchor(None) => Some(format!("#{}.{}", item_type, name)),
699 AssocItemLink::GotoSource(did, provided_methods) => {
700 // We're creating a link from the implementation of an associated item to its
701 // declaration in the trait declaration.
702 let item_type = match item_type {
703 // For historical but not technical reasons, the item type of methods in
704 // trait declarations depends on whether the method is required (`TyMethod`) or
705 // provided (`Method`).
706 ItemType::Method | ItemType::TyMethod => {
707 if provided_methods.contains(&name) {
713 // For associated types and constants, no such distinction exists.
714 item_type => item_type,
717 match href(did.expect_def_id(), cx) {
718 Ok((url, ..)) => Some(format!("{}#{}.{}", url, item_type, name)),
719 // The link is broken since it points to an external crate that wasn't documented.
720 // Do not create any link in such case. This is better than falling back to a
721 // dummy anchor like `#{item_type}.{name}` representing the `id` of *this* impl item
722 // (that used to happen in older versions). Indeed, in most cases this dummy would
723 // coincide with the `id`. However, it would not always do so.
724 // In general, this dummy would be incorrect:
725 // If the type with the trait impl also had an inherent impl with an assoc. item of
726 // the *same* name as this impl item, the dummy would link to that one even though
727 // those two items are distinct!
728 // In this scenario, the actual `id` of this impl item would be
729 // `#{item_type}.{name}-{n}` for some number `n` (a disambiguator).
730 Err(HrefError::DocumentationNotBuilt) => None,
731 Err(_) => Some(format!("#{}.{}", item_type, name)),
736 // If there is no `href` for the reason explained above, simply do not render it which is valid:
737 // https://html.spec.whatwg.org/multipage/links.html#links-created-by-a-and-area-elements
738 href.map(|href| format!(" href=\"{}\"", href)).unwrap_or_default()
745 default: Option<&clean::ConstantKind>,
746 link: AssocItemLink<'_>,
753 "{extra}{vis}const <a{href} class=\"constant\">{name}</a>: {ty}",
755 vis = visibility_print_with_space(it.visibility(tcx), it.item_id, cx),
756 href = assoc_href_attr(it, link, cx),
757 name = it.name.as_ref().unwrap(),
760 if let Some(default) = default {
763 // FIXME: `.value()` uses `clean::utils::format_integer_with_underscore_sep` under the
764 // hood which adds noisy underscores and a type suffix to number literals.
765 // This hurts readability in this context especially when more complex expressions
766 // are involved and it doesn't add much of value.
767 // Find a way to print constants here without all that jazz.
768 write!(w, "{}", Escape(&default.value(tcx).unwrap_or_else(|| default.expr(tcx))));
775 generics: &clean::Generics,
776 bounds: &[clean::GenericBound],
777 default: Option<&clean::Type>,
778 link: AssocItemLink<'_>,
784 "{indent}type <a{href} class=\"associatedtype\">{name}</a>{generics}",
785 indent = " ".repeat(indent),
786 href = assoc_href_attr(it, link, cx),
787 name = it.name.as_ref().unwrap(),
788 generics = generics.print(cx),
790 if !bounds.is_empty() {
791 write!(w, ": {}", print_generic_bounds(bounds, cx))
793 write!(w, "{}", print_where_clause(generics, cx, indent, Ending::NoNewline));
794 if let Some(default) = default {
795 write!(w, " = {}", default.print(cx))
804 link: AssocItemLink<'_>,
806 cx: &mut Context<'_>,
807 render_mode: RenderMode,
810 let header = meth.fn_header(tcx).expect("Trying to get header from a non-function item");
811 let name = meth.name.as_ref().unwrap();
812 let vis = visibility_print_with_space(meth.visibility(tcx), meth.item_id, cx).to_string();
813 // FIXME: Once https://github.com/rust-lang/rust/issues/67792 is implemented, we can remove
815 let constness = match render_mode {
816 RenderMode::Normal => {
817 print_constness_with_space(&header.constness, meth.const_stability(tcx))
819 RenderMode::ForDeref { .. } => "",
821 let asyncness = header.asyncness.print_with_space();
822 let unsafety = header.unsafety.print_with_space();
823 let defaultness = print_default_space(meth.is_default());
824 let abi = print_abi_with_space(header.abi).to_string();
825 let href = assoc_href_attr(meth, link, cx);
827 // NOTE: `{:#}` does not print HTML formatting, `{}` does. So `g.print` can't be reused between the length calculation and `write!`.
828 let generics_len = format!("{:#}", g.print(cx)).len();
829 let mut header_len = "fn ".len()
836 + name.as_str().len()
839 let notable_traits = d.output.as_return().and_then(|output| notable_traits_button(output, cx));
841 let (indent, indent_str, end_newline) = if parent == ItemType::Trait {
843 let indent_str = " ";
844 render_attributes_in_pre(w, meth, indent_str);
845 (4, indent_str, Ending::NoNewline)
847 render_attributes_in_code(w, meth);
848 (0, "", Ending::Newline)
850 w.reserve(header_len + "<a href=\"\" class=\"fn\">{".len() + "</a>".len());
853 "{indent}{vis}{constness}{asyncness}{unsafety}{defaultness}{abi}fn <a{href} class=\"fn\">{name}</a>\
854 {generics}{decl}{notable_traits}{where_clause}",
857 constness = constness,
858 asyncness = asyncness,
860 defaultness = defaultness,
864 generics = g.print(cx),
865 decl = d.full_print(header_len, indent, cx),
866 notable_traits = notable_traits.unwrap_or_default(),
867 where_clause = print_where_clause(g, cx, indent, end_newline),
871 /// Writes a span containing the versions at which an item became stable and/or const-stable. For
872 /// example, if the item became stable at 1.0.0, and const-stable at 1.45.0, this function would
873 /// write a span containing "1.0.0 (const: 1.45.0)".
875 /// Returns `true` if a stability annotation was rendered.
877 /// Stability and const-stability are considered separately. If the item is unstable, no version
878 /// will be written. If the item is const-unstable, "const: unstable" will be appended to the
879 /// span, with a link to the tracking issue if present. If an item's stability or const-stability
880 /// version matches the version of its enclosing item, that version will be omitted.
882 /// Note that it is possible for an unstable function to be const-stable. In that case, the span
883 /// will include the const-stable version, but no stable version will be emitted, as a natural
884 /// consequence of the above rules.
885 fn render_stability_since_raw_with_extra(
888 const_stability: Option<ConstStability>,
889 containing_ver: Option<Symbol>,
890 containing_const_ver: Option<Symbol>,
893 let stable_version = ver.filter(|inner| !inner.is_empty() && Some(*inner) != containing_ver);
895 let mut title = String::new();
896 let mut stability = String::new();
898 if let Some(ver) = stable_version {
899 stability.push_str(ver.as_str());
900 title.push_str(&format!("Stable since Rust version {}", ver));
903 let const_title_and_stability = match const_stability {
904 Some(ConstStability { level: StabilityLevel::Stable { since, .. }, .. })
905 if Some(since) != containing_const_ver =>
907 Some((format!("const since {}", since), format!("const: {}", since)))
909 Some(ConstStability { level: StabilityLevel::Unstable { issue, .. }, feature, .. }) => {
910 let unstable = if let Some(n) = issue {
912 r#"<a href="https://github.com/rust-lang/rust/issues/{}" title="Tracking issue for {}">unstable</a>"#,
916 String::from("unstable")
919 Some((String::from("const unstable"), format!("const: {}", unstable)))
924 if let Some((const_title, const_stability)) = const_title_and_stability {
925 if !title.is_empty() {
926 title.push_str(&format!(", {}", const_title));
928 title.push_str(&const_title);
931 if !stability.is_empty() {
932 stability.push_str(&format!(" ({})", const_stability));
934 stability.push_str(&const_stability);
938 if !stability.is_empty() {
939 write!(w, r#"<span class="since{extra_class}" title="{title}">{stability}</span>"#);
942 !stability.is_empty()
946 fn render_stability_since_raw(
949 const_stability: Option<ConstStability>,
950 containing_ver: Option<Symbol>,
951 containing_const_ver: Option<Symbol>,
953 render_stability_since_raw_with_extra(
958 containing_const_ver,
963 fn render_assoc_item(
966 link: AssocItemLink<'_>,
968 cx: &mut Context<'_>,
969 render_mode: RenderMode,
972 clean::StrippedItem(..) => {}
973 clean::TyMethodItem(m) => {
974 assoc_method(w, item, &m.generics, &m.decl, link, parent, cx, render_mode)
976 clean::MethodItem(m, _) => {
977 assoc_method(w, item, &m.generics, &m.decl, link, parent, cx, render_mode)
979 kind @ (clean::TyAssocConstItem(ty) | clean::AssocConstItem(ty, _)) => assoc_const(
984 clean::TyAssocConstItem(_) => None,
985 clean::AssocConstItem(_, default) => Some(default),
989 if parent == ItemType::Trait { " " } else { "" },
992 clean::TyAssocTypeItem(ref generics, ref bounds) => assoc_type(
999 if parent == ItemType::Trait { 4 } else { 0 },
1002 clean::AssocTypeItem(ref ty, ref bounds) => assoc_type(
1007 Some(ty.item_type.as_ref().unwrap_or(&ty.type_)),
1009 if parent == ItemType::Trait { 4 } else { 0 },
1012 _ => panic!("render_assoc_item called on non-associated-item"),
1016 const ALLOWED_ATTRIBUTES: &[Symbol] =
1017 &[sym::export_name, sym::link_section, sym::no_mangle, sym::repr, sym::non_exhaustive];
1019 fn attributes(it: &clean::Item) -> Vec<String> {
1023 .filter_map(|attr| {
1024 if ALLOWED_ATTRIBUTES.contains(&attr.name_or_empty()) {
1026 pprust::attribute_to_string(attr)
1027 .replace("\\\n", "")
1038 // When an attribute is rendered inside a `<pre>` tag, it is formatted using
1039 // a whitespace prefix and newline.
1040 fn render_attributes_in_pre(w: &mut Buffer, it: &clean::Item, prefix: &str) {
1041 for a in attributes(it) {
1042 writeln!(w, "{}{}", prefix, a);
1046 // When an attribute is rendered inside a <code> tag, it is formatted using
1047 // a div to produce a newline after it.
1048 fn render_attributes_in_code(w: &mut Buffer, it: &clean::Item) {
1049 for a in attributes(it) {
1050 write!(w, "<div class=\"code-attribute\">{}</div>", a);
1054 #[derive(Copy, Clone)]
1055 enum AssocItemLink<'a> {
1056 Anchor(Option<&'a str>),
1057 GotoSource(ItemId, &'a FxHashSet<Symbol>),
1060 impl<'a> AssocItemLink<'a> {
1061 fn anchor(&self, id: &'a str) -> Self {
1063 AssocItemLink::Anchor(_) => AssocItemLink::Anchor(Some(id)),
1064 ref other => *other,
1069 fn write_impl_section_heading(w: &mut Buffer, title: &str, id: &str) {
1072 "<h2 id=\"{id}\" class=\"small-section-header\">\
1074 <a href=\"#{id}\" class=\"anchor\">§</a>\
1079 pub(crate) fn render_all_impls(
1081 cx: &mut Context<'_>,
1082 containing_item: &clean::Item,
1084 synthetic: &[&Impl],
1085 blanket_impl: &[&Impl],
1087 let mut impls = Buffer::empty_from(w);
1088 render_impls(cx, &mut impls, concrete, containing_item, true);
1089 let impls = impls.into_inner();
1090 if !impls.is_empty() {
1091 write_impl_section_heading(w, "Trait Implementations", "trait-implementations");
1092 write!(w, "<div id=\"trait-implementations-list\">{}</div>", impls);
1095 if !synthetic.is_empty() {
1096 write_impl_section_heading(w, "Auto Trait Implementations", "synthetic-implementations");
1097 w.write_str("<div id=\"synthetic-implementations-list\">");
1098 render_impls(cx, w, synthetic, containing_item, false);
1099 w.write_str("</div>");
1102 if !blanket_impl.is_empty() {
1103 write_impl_section_heading(w, "Blanket Implementations", "blanket-implementations");
1104 w.write_str("<div id=\"blanket-implementations-list\">");
1105 render_impls(cx, w, blanket_impl, containing_item, false);
1106 w.write_str("</div>");
1110 fn render_assoc_items(
1112 cx: &mut Context<'_>,
1113 containing_item: &clean::Item,
1115 what: AssocItemRender<'_>,
1117 let mut derefs = FxHashSet::default();
1119 render_assoc_items_inner(w, cx, containing_item, it, what, &mut derefs)
1122 fn render_assoc_items_inner(
1124 cx: &mut Context<'_>,
1125 containing_item: &clean::Item,
1127 what: AssocItemRender<'_>,
1128 derefs: &mut FxHashSet<DefId>,
1130 info!("Documenting associated items of {:?}", containing_item.name);
1131 let shared = Rc::clone(&cx.shared);
1132 let cache = &shared.cache;
1133 let Some(v) = cache.impls.get(&it) else { return };
1134 let (non_trait, traits): (Vec<_>, _) = v.iter().partition(|i| i.inner_impl().trait_.is_none());
1135 if !non_trait.is_empty() {
1136 let mut tmp_buf = Buffer::empty_from(w);
1137 let (render_mode, id) = match what {
1138 AssocItemRender::All => {
1139 write_impl_section_heading(&mut tmp_buf, "Implementations", "implementations");
1140 (RenderMode::Normal, "implementations-list".to_owned())
1142 AssocItemRender::DerefFor { trait_, type_, deref_mut_ } => {
1144 cx.derive_id(small_url_encode(format!("deref-methods-{:#}", type_.print(cx))));
1145 if let Some(def_id) = type_.def_id(cx.cache()) {
1146 cx.deref_id_map.insert(def_id, id.clone());
1148 write_impl_section_heading(
1151 "<span>Methods from {trait_}<Target = {type_}></span>",
1152 trait_ = trait_.print(cx),
1153 type_ = type_.print(cx),
1157 (RenderMode::ForDeref { mut_: deref_mut_ }, cx.derive_id(id))
1160 let mut impls_buf = Buffer::empty_from(w);
1161 for i in &non_trait {
1167 AssocItemLink::Anchor(None),
1171 ImplRenderingParameters {
1172 show_def_docs: true,
1173 show_default_items: true,
1174 show_non_assoc_items: true,
1175 toggle_open_by_default: true,
1179 if !impls_buf.is_empty() {
1180 w.push_buffer(tmp_buf);
1181 write!(w, "<div id=\"{}\">", id);
1182 w.push_buffer(impls_buf);
1183 w.write_str("</div>");
1187 if !traits.is_empty() {
1189 traits.iter().find(|t| t.trait_did() == cx.tcx().lang_items().deref_trait());
1190 if let Some(impl_) = deref_impl {
1192 traits.iter().any(|t| t.trait_did() == cx.tcx().lang_items().deref_mut_trait());
1193 render_deref_methods(w, cx, impl_, containing_item, has_deref_mut, derefs);
1196 // If we were already one level into rendering deref methods, we don't want to render
1197 // anything after recursing into any further deref methods above.
1198 if let AssocItemRender::DerefFor { .. } = what {
1202 let (synthetic, concrete): (Vec<&Impl>, Vec<&Impl>) =
1203 traits.into_iter().partition(|t| t.inner_impl().kind.is_auto());
1204 let (blanket_impl, concrete): (Vec<&Impl>, _) =
1205 concrete.into_iter().partition(|t| t.inner_impl().kind.is_blanket());
1207 render_all_impls(w, cx, containing_item, &concrete, &synthetic, &blanket_impl);
1211 fn render_deref_methods(
1213 cx: &mut Context<'_>,
1215 container_item: &clean::Item,
1217 derefs: &mut FxHashSet<DefId>,
1219 let cache = cx.cache();
1220 let deref_type = impl_.inner_impl().trait_.as_ref().unwrap();
1221 let (target, real_target) = impl_
1225 .find_map(|item| match *item.kind {
1226 clean::AssocTypeItem(box ref t, _) => Some(match *t {
1227 clean::Typedef { item_type: Some(ref type_), .. } => (type_, &t.type_),
1228 _ => (&t.type_, &t.type_),
1232 .expect("Expected associated type binding");
1233 debug!("Render deref methods for {:#?}, target {:#?}", impl_.inner_impl().for_, target);
1235 AssocItemRender::DerefFor { trait_: deref_type, type_: real_target, deref_mut_: deref_mut };
1236 if let Some(did) = target.def_id(cache) {
1237 if let Some(type_did) = impl_.inner_impl().for_.def_id(cache) {
1238 // `impl Deref<Target = S> for S`
1239 if did == type_did || !derefs.insert(did) {
1240 // Avoid infinite cycles
1244 render_assoc_items_inner(w, cx, container_item, did, what, derefs);
1245 } else if let Some(prim) = target.primitive_type() {
1246 if let Some(&did) = cache.primitive_locations.get(&prim) {
1247 render_assoc_items_inner(w, cx, container_item, did, what, derefs);
1252 fn should_render_item(item: &clean::Item, deref_mut_: bool, tcx: TyCtxt<'_>) -> bool {
1253 let self_type_opt = match *item.kind {
1254 clean::MethodItem(ref method, _) => method.decl.self_type(),
1255 clean::TyMethodItem(ref method) => method.decl.self_type(),
1259 if let Some(self_ty) = self_type_opt {
1260 let (by_mut_ref, by_box, by_value) = match self_ty {
1261 SelfTy::SelfBorrowed(_, mutability)
1262 | SelfTy::SelfExplicit(clean::BorrowedRef { mutability, .. }) => {
1263 (mutability == Mutability::Mut, false, false)
1265 SelfTy::SelfExplicit(clean::Type::Path { path }) => {
1266 (false, Some(path.def_id()) == tcx.lang_items().owned_box(), false)
1268 SelfTy::SelfValue => (false, false, true),
1269 _ => (false, false, false),
1272 (deref_mut_ || !by_mut_ref) && !by_box && !by_value
1278 pub(crate) fn notable_traits_button(ty: &clean::Type, cx: &mut Context<'_>) -> Option<String> {
1279 let mut has_notable_trait = false;
1281 let did = ty.def_id(cx.cache())?;
1283 // Box has pass-through impls for Read, Write, Iterator, and Future when the
1284 // boxed type implements one of those. We don't want to treat every Box return
1285 // as being notably an Iterator (etc), though, so we exempt it. Pin has the same
1286 // issue, with a pass-through impl for Future.
1287 if Some(did) == cx.tcx().lang_items().owned_box()
1288 || Some(did) == cx.tcx().lang_items().pin_type()
1293 if let Some(impls) = cx.cache().impls.get(&did) {
1295 let impl_ = i.inner_impl();
1296 if !impl_.for_.without_borrowed_ref().is_same(ty.without_borrowed_ref(), cx.cache()) {
1297 // Two different types might have the same did,
1298 // without actually being the same.
1301 if let Some(trait_) = &impl_.trait_ {
1302 let trait_did = trait_.def_id();
1304 if cx.cache().traits.get(&trait_did).map_or(false, |t| t.is_notable_trait(cx.tcx()))
1306 has_notable_trait = true;
1312 if has_notable_trait {
1313 cx.types_with_notable_traits.insert(ty.clone());
1315 " <a href=\"#\" class=\"notable-traits\" data-ty=\"{ty}\">ⓘ</a>",
1316 ty = Escape(&format!("{:#}", ty.print(cx))),
1323 fn notable_traits_decl(ty: &clean::Type, cx: &Context<'_>) -> (String, String) {
1324 let mut out = Buffer::html();
1326 let did = ty.def_id(cx.cache()).expect("notable_traits_button already checked this");
1328 let impls = cx.cache().impls.get(&did).expect("notable_traits_button already checked this");
1331 let impl_ = i.inner_impl();
1332 if !impl_.for_.without_borrowed_ref().is_same(ty.without_borrowed_ref(), cx.cache()) {
1333 // Two different types might have the same did,
1334 // without actually being the same.
1337 if let Some(trait_) = &impl_.trait_ {
1338 let trait_did = trait_.def_id();
1340 if cx.cache().traits.get(&trait_did).map_or(false, |t| t.is_notable_trait(cx.tcx())) {
1344 "<h3>Notable traits for <code>{}</code></h3>\
1345 <pre class=\"content\"><code>",
1346 impl_.for_.print(cx)
1350 //use the "where" class here to make it small
1353 "<span class=\"where fmt-newline\">{}</span>",
1354 impl_.print(false, cx)
1356 for it in &impl_.items {
1357 if let clean::AssocTypeItem(ref tydef, ref _bounds) = *it.kind {
1358 out.push_str("<span class=\"where fmt-newline\"> ");
1359 let empty_set = FxHashSet::default();
1360 let src_link = AssocItemLink::GotoSource(trait_did.into(), &empty_set);
1365 &[], // intentionally leaving out bounds
1371 out.push_str(";</span>");
1378 write!(&mut out, "</code></pre>",);
1381 (format!("{:#}", ty.print(cx)), out.into_inner())
1384 pub(crate) fn notable_traits_json<'a>(
1385 tys: impl Iterator<Item = &'a clean::Type>,
1388 let mut mp: Vec<(String, String)> = tys.map(|ty| notable_traits_decl(ty, cx)).collect();
1389 mp.sort_by(|(name1, _html1), (name2, _html2)| name1.cmp(name2));
1390 struct NotableTraitsMap(Vec<(String, String)>);
1391 impl Serialize for NotableTraitsMap {
1392 fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
1396 let mut map = serializer.serialize_map(Some(self.0.len()))?;
1397 for item in &self.0 {
1398 map.serialize_entry(&item.0, &item.1)?;
1403 serde_json::to_string(&NotableTraitsMap(mp))
1404 .expect("serialize (string, string) -> json object cannot fail")
1407 #[derive(Clone, Copy, Debug)]
1408 struct ImplRenderingParameters {
1409 show_def_docs: bool,
1410 show_default_items: bool,
1411 /// Whether or not to show methods.
1412 show_non_assoc_items: bool,
1413 toggle_open_by_default: bool,
1418 cx: &mut Context<'_>,
1420 parent: &clean::Item,
1421 link: AssocItemLink<'_>,
1422 render_mode: RenderMode,
1423 use_absolute: Option<bool>,
1425 rendering_params: ImplRenderingParameters,
1427 let shared = Rc::clone(&cx.shared);
1428 let cache = &shared.cache;
1429 let traits = &cache.traits;
1430 let trait_ = i.trait_did().map(|did| &traits[&did]);
1431 let mut close_tags = String::new();
1433 // For trait implementations, the `interesting` output contains all methods that have doc
1434 // comments, and the `boring` output contains all methods that do not. The distinction is
1435 // used to allow hiding the boring methods.
1436 // `containing_item` is used for rendering stability info. If the parent is a trait impl,
1437 // `containing_item` will the grandparent, since trait impls can't have stability attached.
1439 boring: &mut Buffer,
1440 interesting: &mut Buffer,
1441 cx: &mut Context<'_>,
1443 parent: &clean::Item,
1444 containing_item: &clean::Item,
1445 link: AssocItemLink<'_>,
1446 render_mode: RenderMode,
1447 is_default_item: bool,
1448 trait_: Option<&clean::Trait>,
1449 rendering_params: ImplRenderingParameters,
1451 let item_type = item.type_();
1452 let name = item.name.as_ref().unwrap();
1454 let render_method_item = rendering_params.show_non_assoc_items
1455 && match render_mode {
1456 RenderMode::Normal => true,
1457 RenderMode::ForDeref { mut_: deref_mut_ } => {
1458 should_render_item(item, deref_mut_, cx.tcx())
1462 let in_trait_class = if trait_.is_some() { " trait-impl" } else { "" };
1464 let mut doc_buffer = Buffer::empty_from(boring);
1465 let mut info_buffer = Buffer::empty_from(boring);
1466 let mut short_documented = true;
1468 if render_method_item {
1469 if !is_default_item {
1470 if let Some(t) = trait_ {
1471 // The trait item may have been stripped so we might not
1472 // find any documentation or stability for it.
1473 if let Some(it) = t.items.iter().find(|i| i.name == item.name) {
1474 // We need the stability of the item from the trait
1475 // because impls can't have a stability.
1476 if item.doc_value().is_some() {
1477 document_item_info(&mut info_buffer, cx, it, Some(parent));
1478 document_full(&mut doc_buffer, item, cx, HeadingOffset::H5);
1479 short_documented = false;
1481 // In case the item isn't documented,
1482 // provide short documentation from the trait.
1489 rendering_params.show_def_docs,
1494 document_item_info(&mut info_buffer, cx, item, Some(parent));
1495 if rendering_params.show_def_docs {
1496 document_full(&mut doc_buffer, item, cx, HeadingOffset::H5);
1497 short_documented = false;
1507 rendering_params.show_def_docs,
1511 let w = if short_documented && trait_.is_some() { interesting } else { boring };
1513 let toggled = !doc_buffer.is_empty();
1515 let method_toggle_class = if item_type.is_method() { " method-toggle" } else { "" };
1516 write!(w, "<details class=\"rustdoc-toggle{}\" open><summary>", method_toggle_class);
1519 clean::MethodItem(..) | clean::TyMethodItem(_) => {
1520 // Only render when the method is not static or we allow static methods
1521 if render_method_item {
1522 let id = cx.derive_id(format!("{}.{}", item_type, name));
1523 let source_id = trait_
1524 .and_then(|trait_| {
1525 trait_.items.iter().find(|item| {
1526 item.name.map(|n| n.as_str().eq(name.as_str())).unwrap_or(false)
1529 .map(|item| format!("{}.{}", item.type_(), name));
1532 "<section id=\"{}\" class=\"{}{} has-srclink\">",
1533 id, item_type, in_trait_class,
1535 render_rightside(w, cx, item, containing_item, render_mode);
1536 if trait_.is_some() {
1537 // Anchors are only used on trait impls.
1538 write!(w, "<a href=\"#{}\" class=\"anchor\">§</a>", id);
1540 w.write_str("<h4 class=\"code-header\">");
1544 link.anchor(source_id.as_ref().unwrap_or(&id)),
1549 w.write_str("</h4>");
1550 w.write_str("</section>");
1553 kind @ (clean::TyAssocConstItem(ty) | clean::AssocConstItem(ty, _)) => {
1554 let source_id = format!("{}.{}", item_type, name);
1555 let id = cx.derive_id(source_id.clone());
1558 "<section id=\"{}\" class=\"{}{} has-srclink\">",
1559 id, item_type, in_trait_class
1561 render_rightside(w, cx, item, containing_item, render_mode);
1562 if trait_.is_some() {
1563 // Anchors are only used on trait impls.
1564 write!(w, "<a href=\"#{}\" class=\"anchor\">§</a>", id);
1566 w.write_str("<h4 class=\"code-header\">");
1572 clean::TyAssocConstItem(_) => None,
1573 clean::AssocConstItem(_, default) => Some(default),
1574 _ => unreachable!(),
1576 link.anchor(if trait_.is_some() { &source_id } else { &id }),
1580 w.write_str("</h4>");
1581 w.write_str("</section>");
1583 clean::TyAssocTypeItem(generics, bounds) => {
1584 let source_id = format!("{}.{}", item_type, name);
1585 let id = cx.derive_id(source_id.clone());
1586 write!(w, "<section id=\"{}\" class=\"{}{}\">", id, item_type, in_trait_class);
1587 if trait_.is_some() {
1588 // Anchors are only used on trait impls.
1589 write!(w, "<a href=\"#{}\" class=\"anchor\">§</a>", id);
1591 w.write_str("<h4 class=\"code-header\">");
1598 link.anchor(if trait_.is_some() { &source_id } else { &id }),
1602 w.write_str("</h4>");
1603 w.write_str("</section>");
1605 clean::AssocTypeItem(tydef, _bounds) => {
1606 let source_id = format!("{}.{}", item_type, name);
1607 let id = cx.derive_id(source_id.clone());
1610 "<section id=\"{}\" class=\"{}{} has-srclink\">",
1611 id, item_type, in_trait_class
1613 if trait_.is_some() {
1614 // Anchors are only used on trait impls.
1615 write!(w, "<a href=\"#{}\" class=\"anchor\">§</a>", id);
1617 w.write_str("<h4 class=\"code-header\">");
1622 &[], // intentionally leaving out bounds
1623 Some(tydef.item_type.as_ref().unwrap_or(&tydef.type_)),
1624 link.anchor(if trait_.is_some() { &source_id } else { &id }),
1628 w.write_str("</h4>");
1629 w.write_str("</section>");
1631 clean::StrippedItem(..) => return,
1632 _ => panic!("can't make docs for trait item with name {:?}", item.name),
1635 w.push_buffer(info_buffer);
1637 w.write_str("</summary>");
1638 w.push_buffer(doc_buffer);
1639 w.push_str("</details>");
1643 let mut impl_items = Buffer::empty_from(w);
1644 let mut default_impl_items = Buffer::empty_from(w);
1646 for trait_item in &i.inner_impl().items {
1648 &mut default_impl_items,
1652 if trait_.is_some() { &i.impl_item } else { parent },
1662 fn render_default_items(
1663 boring: &mut Buffer,
1664 interesting: &mut Buffer,
1665 cx: &mut Context<'_>,
1668 parent: &clean::Item,
1669 containing_item: &clean::Item,
1670 render_mode: RenderMode,
1671 rendering_params: ImplRenderingParameters,
1673 for trait_item in &t.items {
1674 // Skip over any default trait items that are impossible to call
1675 // (e.g. if it has a `Self: Sized` bound on an unsized type).
1676 if let Some(impl_def_id) = parent.item_id.as_def_id()
1677 && let Some(trait_item_def_id) = trait_item.item_id.as_def_id()
1678 && cx.tcx().is_impossible_method((impl_def_id, trait_item_def_id))
1683 let n = trait_item.name;
1684 if i.items.iter().any(|m| m.name == n) {
1687 let did = i.trait_.as_ref().unwrap().def_id();
1688 let provided_methods = i.provided_trait_methods(cx.tcx());
1689 let assoc_link = AssocItemLink::GotoSource(did.into(), &provided_methods);
1707 // If we've implemented a trait, then also emit documentation for all
1708 // default items which weren't overridden in the implementation block.
1709 // We don't emit documentation for default items if they appear in the
1710 // Implementations on Foreign Types or Implementors sections.
1711 if rendering_params.show_default_items {
1712 if let Some(t) = trait_ {
1713 render_default_items(
1714 &mut default_impl_items,
1726 if render_mode == RenderMode::Normal {
1727 let toggled = !(impl_items.is_empty() && default_impl_items.is_empty());
1729 close_tags.insert_str(0, "</details>");
1732 "<details class=\"rustdoc-toggle implementors-toggle\"{}>",
1733 if rendering_params.toggle_open_by_default { " open" } else { "" }
1735 write!(w, "<summary>")
1737 render_impl_summary(
1743 rendering_params.show_def_docs,
1748 write!(w, "</summary>")
1751 if let Some(ref dox) = i.impl_item.collapsed_doc_value() {
1752 if trait_.is_none() && i.inner_impl().items.is_empty() {
1754 "<div class=\"item-info\">\
1755 <div class=\"stab empty-impl\">This impl block contains no items.</div>
1761 "<div class=\"docblock\">{}</div>",
1764 links: &i.impl_item.links(cx),
1765 ids: &mut cx.id_map,
1766 error_codes: cx.shared.codes,
1767 edition: cx.shared.edition(),
1768 playground: &cx.shared.playground,
1769 heading_offset: HeadingOffset::H4
1775 if !default_impl_items.is_empty() || !impl_items.is_empty() {
1776 w.write_str("<div class=\"impl-items\">");
1777 w.push_buffer(default_impl_items);
1778 w.push_buffer(impl_items);
1779 close_tags.insert_str(0, "</div>");
1781 w.write_str(&close_tags);
1784 // Render the items that appear on the right side of methods, impls, and
1785 // associated types. For example "1.0.0 (const: 1.39.0) · source".
1786 fn render_rightside(
1790 containing_item: &clean::Item,
1791 render_mode: RenderMode,
1795 // FIXME: Once https://github.com/rust-lang/rust/issues/67792 is implemented, we can remove
1797 let (const_stability, const_stable_since) = match render_mode {
1798 RenderMode::Normal => (item.const_stability(tcx), containing_item.const_stable_since(tcx)),
1799 RenderMode::ForDeref { .. } => (None, None),
1801 let src_href = cx.src_href(item);
1802 let has_src_ref = src_href.is_some();
1804 let mut rightside = Buffer::new();
1805 let has_stability = render_stability_since_raw_with_extra(
1807 item.stable_since(tcx),
1809 containing_item.stable_since(tcx),
1811 if has_src_ref { "" } else { " rightside" },
1813 if let Some(l) = src_href {
1815 write!(rightside, " · <a class=\"srclink\" href=\"{}\">source</a>", l)
1817 write!(rightside, "<a class=\"srclink rightside\" href=\"{}\">source</a>", l)
1820 if has_stability && has_src_ref {
1821 write!(w, "<span class=\"rightside\">{}</span>", rightside.into_inner());
1823 w.push_buffer(rightside);
1827 pub(crate) fn render_impl_summary(
1829 cx: &mut Context<'_>,
1831 parent: &clean::Item,
1832 containing_item: &clean::Item,
1833 show_def_docs: bool,
1834 use_absolute: Option<bool>,
1835 // This argument is used to reference same type with different paths to avoid duplication
1836 // in documentation pages for trait with automatic implementations like "Send" and "Sync".
1839 let inner_impl = i.inner_impl();
1840 let id = cx.derive_id(get_id_for_impl(&inner_impl.for_, inner_impl.trait_.as_ref(), cx));
1841 let aliases = if aliases.is_empty() {
1844 format!(" data-aliases=\"{}\"", aliases.join(","))
1846 write!(w, "<section id=\"{}\" class=\"impl has-srclink\"{}>", id, aliases);
1847 render_rightside(w, cx, &i.impl_item, containing_item, RenderMode::Normal);
1848 write!(w, "<a href=\"#{}\" class=\"anchor\">§</a>", id);
1849 write!(w, "<h3 class=\"code-header\">");
1851 if let Some(use_absolute) = use_absolute {
1852 write!(w, "{}", inner_impl.print(use_absolute, cx));
1854 for it in &inner_impl.items {
1855 if let clean::AssocTypeItem(ref tydef, ref _bounds) = *it.kind {
1856 w.write_str("<span class=\"where fmt-newline\"> ");
1861 &[], // intentionally leaving out bounds
1863 AssocItemLink::Anchor(None),
1867 w.write_str(";</span>");
1872 write!(w, "{}", inner_impl.print(false, cx));
1876 let is_trait = inner_impl.trait_.is_some();
1878 if let Some(portability) = portability(&i.impl_item, Some(parent)) {
1879 write!(w, "<span class=\"item-info\">{}</span>", portability);
1883 w.write_str("</section>");
1886 fn print_sidebar(cx: &Context<'_>, it: &clean::Item, buffer: &mut Buffer) {
1889 || it.is_primitive()
1897 "<h2 class=\"location\"><a href=\"#\">{}{}</a></h2>",
1899 clean::ModuleItem(..) =>
1907 it.name.as_ref().unwrap()
1911 buffer.write_str("<div class=\"sidebar-elems\">");
1913 write!(buffer, "<ul class=\"block\">");
1914 if let Some(ref version) = cx.cache().crate_version {
1915 write!(buffer, "<li class=\"version\">Version {}</li>", Escape(version));
1917 write!(buffer, "<li><a id=\"all-types\" href=\"all.html\">All Items</a></li>");
1918 buffer.write_str("</ul>");
1922 clean::StructItem(ref s) => sidebar_struct(cx, buffer, it, s),
1923 clean::TraitItem(ref t) => sidebar_trait(cx, buffer, it, t),
1924 clean::PrimitiveItem(_) => sidebar_primitive(cx, buffer, it),
1925 clean::UnionItem(ref u) => sidebar_union(cx, buffer, it, u),
1926 clean::EnumItem(ref e) => sidebar_enum(cx, buffer, it, e),
1927 clean::TypedefItem(_) => sidebar_typedef(cx, buffer, it),
1928 clean::ModuleItem(ref m) => sidebar_module(buffer, &m.items),
1929 clean::ForeignTypeItem => sidebar_foreign_type(cx, buffer, it),
1933 // The sidebar is designed to display sibling functions, modules and
1934 // other miscellaneous information. since there are lots of sibling
1935 // items (and that causes quadratic growth in large modules),
1936 // we refactor common parts into a shared JavaScript file per module.
1937 // still, we don't move everything into JS because we want to preserve
1938 // as much HTML as possible in order to allow non-JS-enabled browsers
1939 // to navigate the documentation (though slightly inefficiently).
1942 let path: String = cx.current.iter().map(|s| s.as_str()).intersperse("::").collect();
1944 write!(buffer, "<h2><a href=\"index.html\">In {}</a></h2>", path);
1947 // Closes sidebar-elems div.
1948 buffer.write_str("</div>");
1951 fn get_next_url(used_links: &mut FxHashSet<String>, url: String) -> String {
1952 if used_links.insert(url.clone()) {
1956 while !used_links.insert(format!("{}-{}", url, add)) {
1959 format!("{}-{}", url, add)
1962 struct SidebarLink {
1967 impl fmt::Display for SidebarLink {
1968 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1969 write!(f, "<a href=\"#{}\">{}</a>", self.url, self.name)
1973 impl PartialEq for SidebarLink {
1974 fn eq(&self, other: &Self) -> bool {
1975 self.url == other.url
1979 impl Eq for SidebarLink {}
1981 impl PartialOrd for SidebarLink {
1982 fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
1983 Some(self.cmp(other))
1987 impl Ord for SidebarLink {
1988 fn cmp(&self, other: &Self) -> std::cmp::Ordering {
1989 self.url.cmp(&other.url)
1996 used_links: &mut FxHashSet<String>,
1999 ) -> Vec<SidebarLink> {
2002 .filter_map(|item| match item.name {
2003 Some(name) if !name.is_empty() && item.is_method() => {
2004 if !for_deref || should_render_item(item, deref_mut, tcx) {
2007 url: get_next_url(used_links, format!("{}.{}", ItemType::Method, name)),
2015 .collect::<Vec<_>>()
2018 fn get_associated_constants(
2020 used_links: &mut FxHashSet<String>,
2021 ) -> Vec<SidebarLink> {
2024 .filter_map(|item| match item.name {
2025 Some(name) if !name.is_empty() && item.is_associated_const() => Some(SidebarLink {
2027 url: get_next_url(used_links, format!("{}.{}", ItemType::AssocConst, name)),
2031 .collect::<Vec<_>>()
2034 // The point is to url encode any potential character from a type with genericity.
2035 fn small_url_encode(s: String) -> String {
2036 let mut st = String::new();
2037 let mut last_match = 0;
2038 for (idx, c) in s.char_indices() {
2039 let escaped = match c {
2055 st += &s[last_match..idx];
2057 // NOTE: we only expect single byte characters here - which is fine as long as we
2058 // only match single byte characters
2059 last_match = idx + 1;
2062 if last_match != 0 {
2063 st += &s[last_match..];
2070 pub(crate) fn sidebar_render_assoc_items(
2074 concrete: Vec<&Impl>,
2075 synthetic: Vec<&Impl>,
2076 blanket_impl: Vec<&Impl>,
2078 let format_impls = |impls: Vec<&Impl>, id_map: &mut IdMap| {
2079 let mut links = FxHashSet::default();
2084 let trait_ = it.inner_impl().trait_.as_ref()?;
2086 id_map.derive(get_id_for_impl(&it.inner_impl().for_, Some(trait_), cx));
2088 let i_display = format!("{:#}", trait_.print(cx));
2089 let out = Escape(&i_display);
2090 let prefix = match it.inner_impl().polarity {
2091 ty::ImplPolarity::Positive | ty::ImplPolarity::Reservation => "",
2092 ty::ImplPolarity::Negative => "!",
2094 let generated = format!("<a href=\"#{}\">{}{}</a>", encoded, prefix, out);
2095 if links.insert(generated.clone()) { Some(generated) } else { None }
2097 .collect::<Vec<String>>();
2102 let concrete_format = format_impls(concrete, id_map);
2103 let synthetic_format = format_impls(synthetic, id_map);
2104 let blanket_format = format_impls(blanket_impl, id_map);
2106 if !concrete_format.is_empty() {
2107 print_sidebar_block(
2109 "trait-implementations",
2110 "Trait Implementations",
2111 concrete_format.iter(),
2115 if !synthetic_format.is_empty() {
2116 print_sidebar_block(
2118 "synthetic-implementations",
2119 "Auto Trait Implementations",
2120 synthetic_format.iter(),
2124 if !blanket_format.is_empty() {
2125 print_sidebar_block(
2127 "blanket-implementations",
2128 "Blanket Implementations",
2129 blanket_format.iter(),
2134 fn sidebar_assoc_items(cx: &Context<'_>, out: &mut Buffer, it: &clean::Item) {
2135 let did = it.item_id.expect_def_id();
2136 let cache = cx.cache();
2138 if let Some(v) = cache.impls.get(&did) {
2139 let mut used_links = FxHashSet::default();
2140 let mut id_map = IdMap::new();
2143 let used_links_bor = &mut used_links;
2144 let mut assoc_consts = v
2146 .filter(|i| i.inner_impl().trait_.is_none())
2147 .flat_map(|i| get_associated_constants(i.inner_impl(), used_links_bor))
2148 .collect::<Vec<_>>();
2149 if !assoc_consts.is_empty() {
2150 // We want links' order to be reproducible so we don't use unstable sort.
2151 assoc_consts.sort();
2153 print_sidebar_block(
2156 "Associated Constants",
2157 assoc_consts.iter(),
2162 .filter(|i| i.inner_impl().trait_.is_none())
2163 .flat_map(|i| get_methods(i.inner_impl(), false, used_links_bor, false, cx.tcx()))
2164 .collect::<Vec<_>>();
2165 if !methods.is_empty() {
2166 // We want links' order to be reproducible so we don't use unstable sort.
2169 print_sidebar_block(out, "implementations", "Methods", methods.iter());
2173 if v.iter().any(|i| i.inner_impl().trait_.is_some()) {
2174 if let Some(impl_) =
2175 v.iter().find(|i| i.trait_did() == cx.tcx().lang_items().deref_trait())
2177 let mut derefs = FxHashSet::default();
2179 sidebar_deref_methods(cx, out, impl_, v, &mut derefs, &mut used_links);
2182 let (synthetic, concrete): (Vec<&Impl>, Vec<&Impl>) =
2183 v.iter().partition::<Vec<_>, _>(|i| i.inner_impl().kind.is_auto());
2184 let (blanket_impl, concrete): (Vec<&Impl>, Vec<&Impl>) =
2185 concrete.into_iter().partition::<Vec<_>, _>(|i| i.inner_impl().kind.is_blanket());
2187 sidebar_render_assoc_items(cx, out, &mut id_map, concrete, synthetic, blanket_impl);
2192 fn sidebar_deref_methods(
2197 derefs: &mut FxHashSet<DefId>,
2198 used_links: &mut FxHashSet<String>,
2202 debug!("found Deref: {:?}", impl_);
2203 if let Some((target, real_target)) =
2204 impl_.inner_impl().items.iter().find_map(|item| match *item.kind {
2205 clean::AssocTypeItem(box ref t, _) => Some(match *t {
2206 clean::Typedef { item_type: Some(ref type_), .. } => (type_, &t.type_),
2207 _ => (&t.type_, &t.type_),
2212 debug!("found target, real_target: {:?} {:?}", target, real_target);
2213 if let Some(did) = target.def_id(c) {
2214 if let Some(type_did) = impl_.inner_impl().for_.def_id(c) {
2215 // `impl Deref<Target = S> for S`
2216 if did == type_did || !derefs.insert(did) {
2217 // Avoid infinite cycles
2222 let deref_mut = v.iter().any(|i| i.trait_did() == cx.tcx().lang_items().deref_mut_trait());
2223 let inner_impl = target
2226 target.primitive_type().and_then(|prim| c.primitive_locations.get(&prim).cloned())
2228 .and_then(|did| c.impls.get(&did));
2229 if let Some(impls) = inner_impl {
2230 debug!("found inner_impl: {:?}", impls);
2233 .filter(|i| i.inner_impl().trait_.is_none())
2234 .flat_map(|i| get_methods(i.inner_impl(), true, used_links, deref_mut, cx.tcx()))
2235 .collect::<Vec<_>>();
2236 if !ret.is_empty() {
2237 let id = if let Some(target_def_id) = real_target.def_id(c) {
2238 cx.deref_id_map.get(&target_def_id).expect("Deref section without derived id")
2242 let title = format!(
2243 "Methods from {}<Target={}>",
2244 Escape(&format!("{:#}", impl_.inner_impl().trait_.as_ref().unwrap().print(cx))),
2245 Escape(&format!("{:#}", real_target.print(cx))),
2247 // We want links' order to be reproducible so we don't use unstable sort.
2249 print_sidebar_block(out, id, &title, ret.iter());
2253 // Recurse into any further impls that might exist for `target`
2254 if let Some(target_did) = target.def_id(c) {
2255 if let Some(target_impls) = c.impls.get(&target_did) {
2256 if let Some(target_deref_impl) = target_impls.iter().find(|i| {
2260 .map(|t| Some(t.def_id()) == cx.tcx().lang_items().deref_trait())
2263 sidebar_deref_methods(
2277 fn sidebar_struct(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, s: &clean::Struct) {
2278 let mut sidebar = Buffer::new();
2279 let fields = get_struct_fields_name(&s.fields);
2281 if !fields.is_empty() {
2284 print_sidebar_block(&mut sidebar, "fields", "Fields", fields.iter());
2286 Some(CtorKind::Fn) => print_sidebar_title(&mut sidebar, "fields", "Tuple Fields"),
2287 Some(CtorKind::Const) => {}
2291 sidebar_assoc_items(cx, &mut sidebar, it);
2293 if !sidebar.is_empty() {
2294 write!(buf, "<section>{}</section>", sidebar.into_inner());
2298 fn get_id_for_impl(for_: &clean::Type, trait_: Option<&clean::Path>, cx: &Context<'_>) -> String {
2300 Some(t) => small_url_encode(format!("impl-{:#}-for-{:#}", t.print(cx), for_.print(cx))),
2301 None => small_url_encode(format!("impl-{:#}", for_.print(cx))),
2305 fn extract_for_impl_name(item: &clean::Item, cx: &Context<'_>) -> Option<(String, String)> {
2307 clean::ItemKind::ImplItem(ref i) => {
2308 i.trait_.as_ref().map(|trait_| {
2309 // Alternative format produces no URLs,
2310 // so this parameter does nothing.
2311 (format!("{:#}", i.for_.print(cx)), get_id_for_impl(&i.for_, Some(trait_), cx))
2318 fn print_sidebar_title(buf: &mut Buffer, id: &str, title: &str) {
2319 write!(buf, "<h3><a href=\"#{}\">{}</a></h3>", id, title);
2322 fn print_sidebar_block(
2326 items: impl Iterator<Item = impl fmt::Display>,
2328 print_sidebar_title(buf, id, title);
2329 buf.push_str("<ul class=\"block\">");
2331 write!(buf, "<li>{}</li>", item);
2333 buf.push_str("</ul>");
2336 fn sidebar_trait(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, t: &clean::Trait) {
2337 buf.write_str("<section>");
2339 fn print_sidebar_section(
2341 items: &[clean::Item],
2344 filter: impl Fn(&clean::Item) -> bool,
2345 mapper: impl Fn(&str) -> String,
2347 let mut items: Vec<&str> = items
2349 .filter_map(|m| match m.name {
2350 Some(ref name) if filter(m) => Some(name.as_str()),
2353 .collect::<Vec<_>>();
2355 if !items.is_empty() {
2356 items.sort_unstable();
2357 print_sidebar_block(out, id, title, items.into_iter().map(mapper));
2361 print_sidebar_section(
2364 "required-associated-types",
2365 "Required Associated Types",
2366 |m| m.is_ty_associated_type(),
2367 |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::AssocType),
2370 print_sidebar_section(
2373 "provided-associated-types",
2374 "Provided Associated Types",
2375 |m| m.is_associated_type(),
2376 |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::AssocType),
2379 print_sidebar_section(
2382 "required-associated-consts",
2383 "Required Associated Constants",
2384 |m| m.is_ty_associated_const(),
2385 |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::AssocConst),
2388 print_sidebar_section(
2391 "provided-associated-consts",
2392 "Provided Associated Constants",
2393 |m| m.is_associated_const(),
2394 |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::AssocConst),
2397 print_sidebar_section(
2402 |m| m.is_ty_method(),
2403 |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::TyMethod),
2406 print_sidebar_section(
2412 |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::Method),
2415 if let Some(implementors) = cx.cache().implementors.get(&it.item_id.expect_def_id()) {
2416 let mut res = implementors
2418 .filter(|i| !i.is_on_local_type(cx))
2419 .filter_map(|i| extract_for_impl_name(&i.impl_item, cx))
2420 .collect::<Vec<_>>();
2422 if !res.is_empty() {
2424 print_sidebar_block(
2427 "Implementations on Foreign Types",
2428 res.iter().map(|(name, id)| format!("<a href=\"#{}\">{}</a>", id, Escape(name))),
2433 sidebar_assoc_items(cx, buf, it);
2435 print_sidebar_title(buf, "implementors", "Implementors");
2436 if t.is_auto(cx.tcx()) {
2437 print_sidebar_title(buf, "synthetic-implementors", "Auto Implementors");
2440 buf.push_str("</section>")
2443 /// Returns the list of implementations for the primitive reference type, filtering out any
2444 /// implementations that are on concrete or partially generic types, only keeping implementations
2445 /// of the form `impl<T> Trait for &T`.
2446 pub(crate) fn get_filtered_impls_for_reference<'a>(
2447 shared: &'a Rc<SharedContext<'_>>,
2449 ) -> (Vec<&'a Impl>, Vec<&'a Impl>, Vec<&'a Impl>) {
2450 let def_id = it.item_id.expect_def_id();
2451 // If the reference primitive is somehow not defined, exit early.
2452 let Some(v) = shared.cache.impls.get(&def_id) else { return (Vec::new(), Vec::new(), Vec::new()) };
2453 // Since there is no "direct implementation" on the reference primitive type, we filter out
2454 // every implementation which isn't a trait implementation.
2455 let traits = v.iter().filter(|i| i.inner_impl().trait_.is_some());
2456 let (synthetic, concrete): (Vec<&Impl>, Vec<&Impl>) =
2457 traits.partition(|t| t.inner_impl().kind.is_auto());
2459 let (blanket_impl, concrete): (Vec<&Impl>, _) =
2460 concrete.into_iter().partition(|t| t.inner_impl().kind.is_blanket());
2461 // Now we keep only references over full generic types.
2462 let concrete: Vec<_> = concrete
2464 .filter(|t| match t.inner_impl().for_ {
2465 clean::Type::BorrowedRef { ref type_, .. } => type_.is_full_generic(),
2470 (concrete, synthetic, blanket_impl)
2473 fn sidebar_primitive(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item) {
2474 let mut sidebar = Buffer::new();
2476 if it.name.map(|n| n.as_str() != "reference").unwrap_or(false) {
2477 sidebar_assoc_items(cx, &mut sidebar, it);
2479 let shared = Rc::clone(&cx.shared);
2480 let (concrete, synthetic, blanket_impl) = get_filtered_impls_for_reference(&shared, it);
2482 sidebar_render_assoc_items(
2492 if !sidebar.is_empty() {
2493 write!(buf, "<section>{}</section>", sidebar.into_inner());
2497 fn sidebar_typedef(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item) {
2498 let mut sidebar = Buffer::new();
2499 sidebar_assoc_items(cx, &mut sidebar, it);
2501 if !sidebar.is_empty() {
2502 write!(buf, "<section>{}</section>", sidebar.into_inner());
2506 fn get_struct_fields_name(fields: &[clean::Item]) -> Vec<String> {
2507 let mut fields = fields
2509 .filter(|f| matches!(*f.kind, clean::StructFieldItem(..)))
2511 f.name.map(|name| format!("<a href=\"#structfield.{name}\">{name}</a>", name = name))
2513 .collect::<Vec<_>>();
2518 fn sidebar_union(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, u: &clean::Union) {
2519 let mut sidebar = Buffer::new();
2520 let fields = get_struct_fields_name(&u.fields);
2522 if !fields.is_empty() {
2523 print_sidebar_block(&mut sidebar, "fields", "Fields", fields.iter());
2526 sidebar_assoc_items(cx, &mut sidebar, it);
2528 if !sidebar.is_empty() {
2529 write!(buf, "<section>{}</section>", sidebar.into_inner());
2533 fn sidebar_enum(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, e: &clean::Enum) {
2534 let mut sidebar = Buffer::new();
2536 let mut variants = e
2541 .map(|name| format!("<a href=\"#variant.{name}\">{name}</a>", name = name))
2543 .collect::<Vec<_>>();
2544 if !variants.is_empty() {
2545 variants.sort_unstable();
2546 print_sidebar_block(&mut sidebar, "variants", "Variants", variants.iter());
2549 sidebar_assoc_items(cx, &mut sidebar, it);
2551 if !sidebar.is_empty() {
2552 write!(buf, "<section>{}</section>", sidebar.into_inner());
2556 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
2557 pub(crate) enum ItemSection {
2576 AssociatedConstants,
2586 const ALL: &'static [Self] = {
2588 // NOTE: The order here affects the order in the UI.
2608 AssociatedConstants,
2618 fn id(self) -> &'static str {
2620 Self::Reexports => "reexports",
2621 Self::Modules => "modules",
2622 Self::Structs => "structs",
2623 Self::Unions => "unions",
2624 Self::Enums => "enums",
2625 Self::Functions => "functions",
2626 Self::TypeDefinitions => "types",
2627 Self::Statics => "statics",
2628 Self::Constants => "constants",
2629 Self::Traits => "traits",
2630 Self::Implementations => "impls",
2631 Self::TypeMethods => "tymethods",
2632 Self::Methods => "methods",
2633 Self::StructFields => "fields",
2634 Self::Variants => "variants",
2635 Self::Macros => "macros",
2636 Self::PrimitiveTypes => "primitives",
2637 Self::AssociatedTypes => "associated-types",
2638 Self::AssociatedConstants => "associated-consts",
2639 Self::ForeignTypes => "foreign-types",
2640 Self::Keywords => "keywords",
2641 Self::OpaqueTypes => "opaque-types",
2642 Self::AttributeMacros => "attributes",
2643 Self::DeriveMacros => "derives",
2644 Self::TraitAliases => "trait-aliases",
2648 fn name(self) -> &'static str {
2650 Self::Reexports => "Re-exports",
2651 Self::Modules => "Modules",
2652 Self::Structs => "Structs",
2653 Self::Unions => "Unions",
2654 Self::Enums => "Enums",
2655 Self::Functions => "Functions",
2656 Self::TypeDefinitions => "Type Definitions",
2657 Self::Statics => "Statics",
2658 Self::Constants => "Constants",
2659 Self::Traits => "Traits",
2660 Self::Implementations => "Implementations",
2661 Self::TypeMethods => "Type Methods",
2662 Self::Methods => "Methods",
2663 Self::StructFields => "Struct Fields",
2664 Self::Variants => "Variants",
2665 Self::Macros => "Macros",
2666 Self::PrimitiveTypes => "Primitive Types",
2667 Self::AssociatedTypes => "Associated Types",
2668 Self::AssociatedConstants => "Associated Constants",
2669 Self::ForeignTypes => "Foreign Types",
2670 Self::Keywords => "Keywords",
2671 Self::OpaqueTypes => "Opaque Types",
2672 Self::AttributeMacros => "Attribute Macros",
2673 Self::DeriveMacros => "Derive Macros",
2674 Self::TraitAliases => "Trait Aliases",
2679 fn item_ty_to_section(ty: ItemType) -> ItemSection {
2681 ItemType::ExternCrate | ItemType::Import => ItemSection::Reexports,
2682 ItemType::Module => ItemSection::Modules,
2683 ItemType::Struct => ItemSection::Structs,
2684 ItemType::Union => ItemSection::Unions,
2685 ItemType::Enum => ItemSection::Enums,
2686 ItemType::Function => ItemSection::Functions,
2687 ItemType::Typedef => ItemSection::TypeDefinitions,
2688 ItemType::Static => ItemSection::Statics,
2689 ItemType::Constant => ItemSection::Constants,
2690 ItemType::Trait => ItemSection::Traits,
2691 ItemType::Impl => ItemSection::Implementations,
2692 ItemType::TyMethod => ItemSection::TypeMethods,
2693 ItemType::Method => ItemSection::Methods,
2694 ItemType::StructField => ItemSection::StructFields,
2695 ItemType::Variant => ItemSection::Variants,
2696 ItemType::Macro => ItemSection::Macros,
2697 ItemType::Primitive => ItemSection::PrimitiveTypes,
2698 ItemType::AssocType => ItemSection::AssociatedTypes,
2699 ItemType::AssocConst => ItemSection::AssociatedConstants,
2700 ItemType::ForeignType => ItemSection::ForeignTypes,
2701 ItemType::Keyword => ItemSection::Keywords,
2702 ItemType::OpaqueTy => ItemSection::OpaqueTypes,
2703 ItemType::ProcAttribute => ItemSection::AttributeMacros,
2704 ItemType::ProcDerive => ItemSection::DeriveMacros,
2705 ItemType::TraitAlias => ItemSection::TraitAliases,
2709 pub(crate) fn sidebar_module_like(buf: &mut Buffer, item_sections_in_use: FxHashSet<ItemSection>) {
2710 use std::fmt::Write as _;
2712 let mut sidebar = String::new();
2714 for &sec in ItemSection::ALL.iter().filter(|sec| item_sections_in_use.contains(sec)) {
2715 let _ = write!(sidebar, "<li><a href=\"#{}\">{}</a></li>", sec.id(), sec.name());
2718 if !sidebar.is_empty() {
2722 <ul class=\"block\">{}</ul>\
2729 fn sidebar_module(buf: &mut Buffer, items: &[clean::Item]) {
2730 let item_sections_in_use: FxHashSet<_> = items
2737 if let clean::ImportItem(ref i) = *it.kind &&
2738 let clean::ImportKind::Simple(s) = i.kind { Some(s) } else { None }
2742 .map(|it| item_ty_to_section(it.type_()))
2745 sidebar_module_like(buf, item_sections_in_use);
2748 fn sidebar_foreign_type(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item) {
2749 let mut sidebar = Buffer::new();
2750 sidebar_assoc_items(cx, &mut sidebar, it);
2752 if !sidebar.is_empty() {
2753 write!(buf, "<section>{}</section>", sidebar.into_inner());
2757 pub(crate) const BASIC_KEYWORDS: &str = "rust, rustlang, rust-lang";
2759 /// Returns a list of all paths used in the type.
2760 /// This is used to help deduplicate imported impls
2761 /// for reexported types. If any of the contained
2762 /// types are re-exported, we don't use the corresponding
2763 /// entry from the js file, as inlining will have already
2764 /// picked up the impl
2765 fn collect_paths_for_type(first_ty: clean::Type, cache: &Cache) -> Vec<String> {
2766 let mut out = Vec::new();
2767 let mut visited = FxHashSet::default();
2768 let mut work = VecDeque::new();
2770 let mut process_path = |did: DefId| {
2771 let get_extern = || cache.external_paths.get(&did).map(|s| s.0.clone());
2772 let fqp = cache.exact_paths.get(&did).cloned().or_else(get_extern);
2774 if let Some(path) = fqp {
2775 out.push(join_with_double_colon(&path));
2779 work.push_back(first_ty);
2781 while let Some(ty) = work.pop_front() {
2782 if !visited.insert(ty.clone()) {
2787 clean::Type::Path { path } => process_path(path.def_id()),
2788 clean::Type::Tuple(tys) => {
2789 work.extend(tys.into_iter());
2791 clean::Type::Slice(ty) => {
2792 work.push_back(*ty);
2794 clean::Type::Array(ty, _) => {
2795 work.push_back(*ty);
2797 clean::Type::RawPointer(_, ty) => {
2798 work.push_back(*ty);
2800 clean::Type::BorrowedRef { type_, .. } => {
2801 work.push_back(*type_);
2803 clean::Type::QPath(box clean::QPathData { self_type, trait_, .. }) => {
2804 work.push_back(self_type);
2805 process_path(trait_.def_id());
2813 const MAX_FULL_EXAMPLES: usize = 5;
2814 const NUM_VISIBLE_LINES: usize = 10;
2816 /// Generates the HTML for example call locations generated via the --scrape-examples flag.
2817 fn render_call_locations(w: &mut Buffer, cx: &mut Context<'_>, item: &clean::Item) {
2819 let def_id = item.item_id.expect_def_id();
2820 let key = tcx.def_path_hash(def_id);
2821 let Some(call_locations) = cx.shared.call_locations.get(&key) else { return };
2823 // Generate a unique ID so users can link to this section for a given method
2824 let id = cx.id_map.derive("scraped-examples");
2827 "<div class=\"docblock scraped-example-list\">\
2830 <a href=\"#{id}\">Examples found in repository</a>\
2831 <a class=\"scrape-help\" href=\"{root_path}scrape-examples-help.html\">?</a>\
2833 root_path = cx.root_path(),
2837 // Create a URL to a particular location in a reverse-dependency's source file
2838 let link_to_loc = |call_data: &CallData, loc: &CallLocation| -> (String, String) {
2839 let (line_lo, line_hi) = loc.call_expr.line_span;
2840 let (anchor, title) = if line_lo == line_hi {
2841 ((line_lo + 1).to_string(), format!("line {}", line_lo + 1))
2844 format!("{}-{}", line_lo + 1, line_hi + 1),
2845 format!("lines {}-{}", line_lo + 1, line_hi + 1),
2848 let url = format!("{}{}#{}", cx.root_path(), call_data.url, anchor);
2852 // Generate the HTML for a single example, being the title and code block
2853 let write_example = |w: &mut Buffer, (path, call_data): (&PathBuf, &CallData)| -> bool {
2854 let contents = match fs::read_to_string(&path) {
2855 Ok(contents) => contents,
2857 let span = item.span(tcx).map_or(rustc_span::DUMMY_SP, |span| span.inner());
2859 .span_err(span, &format!("failed to read file {}: {}", path.display(), err));
2864 // To reduce file sizes, we only want to embed the source code needed to understand the example, not
2865 // the entire file. So we find the smallest byte range that covers all items enclosing examples.
2866 assert!(!call_data.locations.is_empty());
2868 call_data.locations.iter().min_by_key(|loc| loc.enclosing_item.byte_span.0).unwrap();
2869 let byte_min = min_loc.enclosing_item.byte_span.0;
2870 let line_min = min_loc.enclosing_item.line_span.0;
2872 call_data.locations.iter().max_by_key(|loc| loc.enclosing_item.byte_span.1).unwrap();
2873 let byte_max = max_loc.enclosing_item.byte_span.1;
2874 let line_max = max_loc.enclosing_item.line_span.1;
2876 // The output code is limited to that byte range.
2877 let contents_subset = &contents[(byte_min as usize)..(byte_max as usize)];
2879 // The call locations need to be updated to reflect that the size of the program has changed.
2880 // Specifically, the ranges are all subtracted by `byte_min` since that's the new zero point.
2881 let (mut byte_ranges, line_ranges): (Vec<_>, Vec<_>) = call_data
2885 let (byte_lo, byte_hi) = loc.call_ident.byte_span;
2886 let (line_lo, line_hi) = loc.call_expr.line_span;
2887 let byte_range = (byte_lo - byte_min, byte_hi - byte_min);
2889 let line_range = (line_lo - line_min, line_hi - line_min);
2890 let (line_url, line_title) = link_to_loc(call_data, loc);
2892 (byte_range, (line_range, line_url, line_title))
2896 let (_, init_url, init_title) = &line_ranges[0];
2897 let needs_expansion = line_max - line_min > NUM_VISIBLE_LINES;
2898 let locations_encoded = serde_json::to_string(&line_ranges).unwrap();
2902 "<div class=\"scraped-example {expanded_cls}\" data-locs=\"{locations}\">\
2903 <div class=\"scraped-example-title\">\
2904 {name} (<a href=\"{url}\">{title}</a>)\
2906 <div class=\"code-wrapper\">",
2907 expanded_cls = if needs_expansion { "" } else { "expanded" },
2908 name = call_data.display_name,
2911 // The locations are encoded as a data attribute, so they can be read
2912 // later by the JS for interactions.
2913 locations = Escape(&locations_encoded)
2916 if line_ranges.len() > 1 {
2917 write!(w, r#"<button class="prev">≺</button> <button class="next">≻</button>"#);
2920 // Look for the example file in the source map if it exists, otherwise return a dummy span
2921 let file_span = (|| {
2922 let source_map = tcx.sess.source_map();
2923 let crate_src = tcx.sess.local_crate_source_file.as_ref()?;
2924 let abs_crate_src = crate_src.canonicalize().ok()?;
2925 let crate_root = abs_crate_src.parent()?.parent()?;
2926 let rel_path = path.strip_prefix(crate_root).ok()?;
2927 let files = source_map.files();
2928 let file = files.iter().find(|file| match &file.name {
2929 FileName::Real(RealFileName::LocalPath(other_path)) => rel_path == other_path,
2932 Some(rustc_span::Span::with_root_ctxt(
2933 file.start_pos + BytePos(byte_min),
2934 file.start_pos + BytePos(byte_max),
2937 .unwrap_or(rustc_span::DUMMY_SP);
2939 let mut decoration_info = FxHashMap::default();
2940 decoration_info.insert("highlight focus", vec![byte_ranges.remove(0)]);
2941 decoration_info.insert("highlight", byte_ranges);
2949 highlight::DecorationInfo(decoration_info),
2950 sources::SourceContext::Embedded { offset: line_min, needs_expansion },
2952 write!(w, "</div></div>");
2957 // The call locations are output in sequence, so that sequence needs to be determined.
2958 // Ideally the most "relevant" examples would be shown first, but there's no general algorithm
2959 // for determining relevance. We instead proxy relevance with the following heuristics:
2960 // 1. Code written to be an example is better than code not written to be an example, e.g.
2961 // a snippet from examples/foo.rs is better than src/lib.rs. We don't know the Cargo
2962 // directory structure in Rustdoc, so we proxy this by prioritizing code that comes from
2963 // a --crate-type bin.
2964 // 2. Smaller examples are better than large examples. So we prioritize snippets that have
2965 // the smallest number of lines in their enclosing item.
2966 // 3. Finally we sort by the displayed file name, which is arbitrary but prevents the
2967 // ordering of examples from randomly changing between Rustdoc invocations.
2968 let ordered_locations = {
2969 fn sort_criterion<'a>(
2970 (_, call_data): &(&PathBuf, &'a CallData),
2971 ) -> (bool, u32, &'a String) {
2972 // Use the first location because that's what the user will see initially
2973 let (lo, hi) = call_data.locations[0].enclosing_item.byte_span;
2974 (!call_data.is_bin, hi - lo, &call_data.display_name)
2977 let mut locs = call_locations.iter().collect::<Vec<_>>();
2978 locs.sort_by_key(sort_criterion);
2982 let mut it = ordered_locations.into_iter().peekable();
2984 // An example may fail to write if its source can't be read for some reason, so this method
2985 // continues iterating until a write succeeds
2986 let write_and_skip_failure = |w: &mut Buffer, it: &mut Peekable<_>| {
2987 while let Some(example) = it.next() {
2988 if write_example(&mut *w, example) {
2994 // Write just one example that's visible by default in the method's description.
2995 write_and_skip_failure(w, &mut it);
2997 // Then add the remaining examples in a hidden section.
2998 if it.peek().is_some() {
3001 "<details class=\"rustdoc-toggle more-examples-toggle\">\
3002 <summary class=\"hideme\">\
3003 <span>More examples</span>\
3005 <div class=\"hide-more\">Hide additional examples</div>\
3006 <div class=\"more-scraped-examples\">\
3007 <div class=\"toggle-line\"><div class=\"toggle-line-inner\"></div></div>\
3008 <div class=\"more-scraped-examples-inner\">"
3011 // Only generate inline code for MAX_FULL_EXAMPLES number of examples. Otherwise we could
3012 // make the page arbitrarily huge!
3013 for _ in 0..MAX_FULL_EXAMPLES {
3014 write_and_skip_failure(w, &mut it);
3017 // For the remaining examples, generate a <ul> containing links to the source files.
3018 if it.peek().is_some() {
3019 write!(w, r#"<div class="example-links">Additional examples can be found in:<br><ul>"#);
3020 it.for_each(|(_, call_data)| {
3021 let (url, _) = link_to_loc(call_data, &call_data.locations[0]);
3024 r#"<li><a href="{url}">{name}</a></li>"#,
3026 name = call_data.display_name
3029 write!(w, "</ul></div>");
3032 write!(w, "</div></div></details>");
3035 write!(w, "</div>");