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::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, Buffer, HrefError,
76 use crate::html::highlight;
77 use crate::html::markdown::{HeadingOffset, IdMap, Markdown, MarkdownHtml, MarkdownSummaryLine};
78 use crate::html::sources;
79 use crate::html::static_files::SCRAPE_EXAMPLES_HELP_MD;
80 use crate::scrape_examples::{CallData, CallLocation};
82 use crate::DOC_RUST_LANG_ORG_CHANNEL;
84 /// A pair of name and its optional document.
85 pub(crate) type NameDoc = (String, Option<String>);
87 pub(crate) fn ensure_trailing_slash(v: &str) -> impl fmt::Display + '_ {
88 crate::html::format::display_fn(move |f| {
89 if !v.ends_with('/') && !v.is_empty() { write!(f, "{}/", v) } else { f.write_str(v) }
93 // Helper structs for rendering items/sidebars and carrying along contextual
96 /// Struct representing one entry in the JS search index. These are all emitted
97 /// by hand to a large JS file at the end of cache-creation.
99 pub(crate) struct IndexItem {
100 pub(crate) ty: ItemType,
101 pub(crate) name: String,
102 pub(crate) path: String,
103 pub(crate) desc: String,
104 pub(crate) parent: Option<DefId>,
105 pub(crate) parent_idx: Option<usize>,
106 pub(crate) search_type: Option<IndexItemFunctionType>,
107 pub(crate) aliases: Box<[Symbol]>,
110 /// A type used for the search index.
112 pub(crate) struct RenderType {
113 id: Option<RenderTypeId>,
114 generics: Option<Vec<RenderType>>,
117 impl Serialize for RenderType {
118 fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
122 let id = match &self.id {
123 // 0 is a sentinel, everything else is one-indexed
125 Some(RenderTypeId::Index(idx)) => idx + 1,
126 _ => panic!("must convert render types to indexes before serializing"),
128 if let Some(generics) = &self.generics {
129 let mut seq = serializer.serialize_seq(None)?;
130 seq.serialize_element(&id)?;
131 seq.serialize_element(generics)?;
134 id.serialize(serializer)
139 #[derive(Clone, Debug)]
140 pub(crate) enum RenderTypeId {
142 Primitive(clean::PrimitiveType),
146 /// Full type of functions/methods in the search index.
148 pub(crate) struct IndexItemFunctionType {
149 inputs: Vec<RenderType>,
150 output: Vec<RenderType>,
153 impl Serialize for IndexItemFunctionType {
154 fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
158 // If we couldn't figure out a type, just write `0`.
159 let has_missing = self
162 .chain(self.output.iter())
163 .any(|i| i.id.is_none() && i.generics.is_none());
165 0.serialize(serializer)
167 let mut seq = serializer.serialize_seq(None)?;
168 match &self.inputs[..] {
169 [one] if one.generics.is_none() => seq.serialize_element(one)?,
170 _ => seq.serialize_element(&self.inputs)?,
172 match &self.output[..] {
174 [one] if one.generics.is_none() => seq.serialize_element(one)?,
175 _ => seq.serialize_element(&self.output)?,
182 #[derive(Debug, Clone)]
183 pub(crate) struct StylePath {
184 /// The path to the theme
185 pub(crate) path: PathBuf,
189 pub(crate) fn basename(&self) -> Result<String, Error> {
190 Ok(try_none!(try_none!(self.path.file_stem(), &self.path).to_str(), &self.path).to_string())
194 fn write_srclink(cx: &Context<'_>, item: &clean::Item, buf: &mut Buffer) {
195 if let Some(l) = cx.src_href(item) {
196 write!(buf, "<a class=\"srclink\" href=\"{}\">source</a>", l)
200 #[derive(Debug, Eq, PartialEq, Hash)]
207 fn new(mut url: String, name: String) -> ItemEntry {
208 while url.starts_with('/') {
211 ItemEntry { url, name }
216 pub(crate) fn print(&self) -> impl fmt::Display + '_ {
217 crate::html::format::display_fn(move |f| {
218 write!(f, "<a href=\"{}\">{}</a>", self.url, Escape(&self.name))
223 impl PartialOrd for ItemEntry {
224 fn partial_cmp(&self, other: &ItemEntry) -> Option<::std::cmp::Ordering> {
225 Some(self.cmp(other))
229 impl Ord for ItemEntry {
230 fn cmp(&self, other: &ItemEntry) -> ::std::cmp::Ordering {
231 self.name.cmp(&other.name)
237 structs: FxHashSet<ItemEntry>,
238 enums: FxHashSet<ItemEntry>,
239 unions: FxHashSet<ItemEntry>,
240 primitives: FxHashSet<ItemEntry>,
241 traits: FxHashSet<ItemEntry>,
242 macros: FxHashSet<ItemEntry>,
243 functions: FxHashSet<ItemEntry>,
244 typedefs: FxHashSet<ItemEntry>,
245 opaque_tys: FxHashSet<ItemEntry>,
246 statics: FxHashSet<ItemEntry>,
247 constants: FxHashSet<ItemEntry>,
248 attributes: FxHashSet<ItemEntry>,
249 derives: FxHashSet<ItemEntry>,
250 trait_aliases: FxHashSet<ItemEntry>,
254 fn new() -> AllTypes {
255 let new_set = |cap| FxHashSet::with_capacity_and_hasher(cap, Default::default());
257 structs: new_set(100),
259 unions: new_set(100),
260 primitives: new_set(26),
261 traits: new_set(100),
262 macros: new_set(100),
263 functions: new_set(100),
264 typedefs: new_set(100),
265 opaque_tys: new_set(100),
266 statics: new_set(100),
267 constants: new_set(100),
268 attributes: new_set(100),
269 derives: new_set(100),
270 trait_aliases: new_set(100),
274 fn append(&mut self, item_name: String, item_type: &ItemType) {
275 let mut url: Vec<_> = item_name.split("::").skip(1).collect();
276 if let Some(name) = url.pop() {
277 let new_url = format!("{}/{}.{}.html", url.join("/"), item_type, name);
279 let name = url.join("::");
281 ItemType::Struct => self.structs.insert(ItemEntry::new(new_url, name)),
282 ItemType::Enum => self.enums.insert(ItemEntry::new(new_url, name)),
283 ItemType::Union => self.unions.insert(ItemEntry::new(new_url, name)),
284 ItemType::Primitive => self.primitives.insert(ItemEntry::new(new_url, name)),
285 ItemType::Trait => self.traits.insert(ItemEntry::new(new_url, name)),
286 ItemType::Macro => self.macros.insert(ItemEntry::new(new_url, name)),
287 ItemType::Function => self.functions.insert(ItemEntry::new(new_url, name)),
288 ItemType::Typedef => self.typedefs.insert(ItemEntry::new(new_url, name)),
289 ItemType::OpaqueTy => self.opaque_tys.insert(ItemEntry::new(new_url, name)),
290 ItemType::Static => self.statics.insert(ItemEntry::new(new_url, name)),
291 ItemType::Constant => self.constants.insert(ItemEntry::new(new_url, name)),
292 ItemType::ProcAttribute => self.attributes.insert(ItemEntry::new(new_url, name)),
293 ItemType::ProcDerive => self.derives.insert(ItemEntry::new(new_url, name)),
294 ItemType::TraitAlias => self.trait_aliases.insert(ItemEntry::new(new_url, name)),
302 fn print(self, f: &mut Buffer) {
303 fn print_entries(f: &mut Buffer, e: &FxHashSet<ItemEntry>, title: &str, class: &str) {
305 let mut e: Vec<&ItemEntry> = e.iter().collect();
309 "<h3 id=\"{}\">{}</h3><ul class=\"{} docblock\">",
310 title.replace(' ', "-"), // IDs cannot contain whitespaces.
316 write!(f, "<li>{}</li>", s.print());
319 f.write_str("</ul>");
325 <span class=\"in-band\">List of all items</span>\
328 // Note: print_entries does not escape the title, because we know the current set of titles
329 // doesn't require escaping.
330 print_entries(f, &self.structs, "Structs", "structs");
331 print_entries(f, &self.enums, "Enums", "enums");
332 print_entries(f, &self.unions, "Unions", "unions");
333 print_entries(f, &self.primitives, "Primitives", "primitives");
334 print_entries(f, &self.traits, "Traits", "traits");
335 print_entries(f, &self.macros, "Macros", "macros");
336 print_entries(f, &self.attributes, "Attribute Macros", "attributes");
337 print_entries(f, &self.derives, "Derive Macros", "derives");
338 print_entries(f, &self.functions, "Functions", "functions");
339 print_entries(f, &self.typedefs, "Typedefs", "typedefs");
340 print_entries(f, &self.trait_aliases, "Trait Aliases", "trait-aliases");
341 print_entries(f, &self.opaque_tys, "Opaque Types", "opaque-types");
342 print_entries(f, &self.statics, "Statics", "statics");
343 print_entries(f, &self.constants, "Constants", "constants")
347 fn scrape_examples_help(shared: &SharedContext<'_>) -> String {
348 let mut content = SCRAPE_EXAMPLES_HELP_MD.to_owned();
349 content.push_str(&format!(
350 "## More information\n\n\
351 If you want more information about this feature, please read the [corresponding chapter in the Rustdoc book]({}/rustdoc/scraped-examples.html).",
352 DOC_RUST_LANG_ORG_CHANNEL));
354 let mut ids = IdMap::default();
356 "<div class=\"main-heading\">\
358 <span class=\"in-band\">About scraped examples</span>\
366 error_codes: shared.codes,
367 edition: shared.edition(),
368 playground: &shared.playground,
369 heading_offset: HeadingOffset::H1
377 cx: &mut Context<'_>,
379 parent: Option<&clean::Item>,
380 heading_offset: HeadingOffset,
382 if let Some(ref name) = item.name {
383 info!("Documenting {}", name);
385 document_item_info(w, cx, item, parent);
386 if parent.is_none() {
387 document_full_collapsible(w, item, cx, heading_offset);
389 document_full(w, item, cx, heading_offset);
393 /// Render md_text as markdown.
396 cx: &mut Context<'_>,
398 links: Vec<RenderedLink>,
399 heading_offset: HeadingOffset,
403 "<div class=\"docblock\">{}</div>",
408 error_codes: cx.shared.codes,
409 edition: cx.shared.edition(),
410 playground: &cx.shared.playground,
417 /// Writes a documentation block containing only the first paragraph of the documentation. If the
418 /// docs are longer, a "Read more" link is appended to the end.
422 cx: &mut Context<'_>,
423 link: AssocItemLink<'_>,
424 parent: &clean::Item,
427 document_item_info(w, cx, item, Some(parent));
431 if let Some(s) = item.doc_value() {
432 let mut summary_html = MarkdownSummaryLine(&s, &item.links(cx)).into_string();
434 if s.contains('\n') {
435 let link = format!(r#" <a{}>Read more</a>"#, assoc_href_attr(item, link, cx));
437 if let Some(idx) = summary_html.rfind("</p>") {
438 summary_html.insert_str(idx, &link);
440 summary_html.push_str(&link);
444 write!(w, "<div class='docblock'>{}</div>", summary_html,);
448 fn document_full_collapsible(
451 cx: &mut Context<'_>,
452 heading_offset: HeadingOffset,
454 document_full_inner(w, item, cx, true, heading_offset);
460 cx: &mut Context<'_>,
461 heading_offset: HeadingOffset,
463 document_full_inner(w, item, cx, false, heading_offset);
466 fn document_full_inner(
469 cx: &mut Context<'_>,
470 is_collapsible: bool,
471 heading_offset: HeadingOffset,
473 if let Some(s) = item.collapsed_doc_value() {
474 debug!("Doc block: =====\n{}\n=====", s);
477 "<details class=\"rustdoc-toggle top-doc\" open>\
478 <summary class=\"hideme\">\
479 <span>Expand description</span>\
482 render_markdown(w, cx, &s, item.links(cx), heading_offset);
483 w.write_str("</details>");
485 render_markdown(w, cx, &s, item.links(cx), heading_offset);
489 let kind = match &*item.kind {
490 clean::ItemKind::StrippedItem(box kind) | kind => kind,
493 if let clean::ItemKind::FunctionItem(..) | clean::ItemKind::MethodItem(..) = kind {
494 render_call_locations(w, cx, item);
498 /// Add extra information about an item such as:
502 /// * Required features (through the `doc_cfg` feature)
503 fn document_item_info(
505 cx: &mut Context<'_>,
507 parent: Option<&clean::Item>,
509 let item_infos = short_item_info(item, cx, parent);
510 if !item_infos.is_empty() {
511 w.write_str("<span class=\"item-info\">");
512 for info in item_infos {
515 w.write_str("</span>");
519 fn portability(item: &clean::Item, parent: Option<&clean::Item>) -> Option<String> {
520 let cfg = match (&item.cfg, parent.and_then(|p| p.cfg.as_ref())) {
521 (Some(cfg), Some(parent_cfg)) => cfg.simplify_with(parent_cfg),
522 (cfg, _) => cfg.as_deref().cloned(),
525 debug!("Portability {:?} - {:?} = {:?}", item.cfg, parent.and_then(|p| p.cfg.as_ref()), cfg);
527 Some(format!("<div class=\"stab portability\">{}</div>", cfg?.render_long_html()))
530 /// Render the stability, deprecation and portability information that is displayed at the top of
531 /// the item's documentation.
534 cx: &mut Context<'_>,
535 parent: Option<&clean::Item>,
537 let mut extra_info = vec![];
538 let error_codes = cx.shared.codes;
540 if let Some(depr @ Deprecation { note, since, is_since_rustc_version: _, suggestion: _ }) =
541 item.deprecation(cx.tcx())
543 // We display deprecation messages for #[deprecated], but only display
544 // the future-deprecation messages for rustc versions.
545 let mut message = if let Some(since) = since {
546 let since = since.as_str();
547 if !stability::deprecation_in_effect(&depr) {
549 String::from("Deprecating in a future Rust version")
551 format!("Deprecating in {}", Escape(since))
554 format!("Deprecated since {}", Escape(since))
557 String::from("Deprecated")
560 if let Some(note) = note {
561 let note = note.as_str();
562 let html = MarkdownHtml(
567 &cx.shared.playground,
569 message.push_str(&format!(": {}", html.into_string()));
571 extra_info.push(format!(
572 "<div class=\"stab deprecated\"><span class=\"emoji\">👎</span> {}</div>",
577 // Render unstable items. But don't render "rustc_private" crates (internal compiler crates).
578 // Those crates are permanently unstable so it makes no sense to render "unstable" everywhere.
579 if let Some((StabilityLevel::Unstable { reason: _, issue, .. }, feature)) = item
582 .filter(|stab| stab.feature != sym::rustc_private)
583 .map(|stab| (stab.level, stab.feature))
586 "<span class=\"emoji\">🔬</span> This is a nightly-only experimental API.".to_owned();
588 let mut feature = format!("<code>{}</code>", Escape(feature.as_str()));
589 if let (Some(url), Some(issue)) = (&cx.shared.issue_tracker_base_url, issue) {
590 feature.push_str(&format!(
591 " <a href=\"{url}{issue}\">#{issue}</a>",
597 message.push_str(&format!(" ({})", feature));
599 extra_info.push(format!("<div class=\"stab unstable\">{}</div>", message));
602 if let Some(portability) = portability(item, parent) {
603 extra_info.push(portability);
609 // Render the list of items inside one of the sections "Trait Implementations",
610 // "Auto Trait Implementations," "Blanket Trait Implementations" (on struct/enum pages).
612 cx: &mut Context<'_>,
615 containing_item: &clean::Item,
616 toggle_open_by_default: bool,
619 let mut rendered_impls = impls
622 let did = i.trait_did().unwrap();
623 let provided_trait_methods = i.inner_impl().provided_trait_methods(tcx);
624 let assoc_link = AssocItemLink::GotoSource(did.into(), &provided_trait_methods);
625 let mut buffer = if w.is_for_html() { Buffer::html() } else { Buffer::new() };
635 ImplRenderingParameters {
637 is_on_foreign_type: false,
638 show_default_items: true,
639 show_non_assoc_items: true,
640 toggle_open_by_default,
645 .collect::<Vec<_>>();
646 rendered_impls.sort();
647 w.write_str(&rendered_impls.join(""));
650 /// Build a (possibly empty) `href` attribute (a key-value pair) for the given associated item.
651 fn assoc_href_attr(it: &clean::Item, link: AssocItemLink<'_>, cx: &Context<'_>) -> String {
652 let name = it.name.unwrap();
653 let item_type = it.type_();
655 let href = match link {
656 AssocItemLink::Anchor(Some(ref id)) => Some(format!("#{}", id)),
657 AssocItemLink::Anchor(None) => Some(format!("#{}.{}", item_type, name)),
658 AssocItemLink::GotoSource(did, provided_methods) => {
659 // We're creating a link from the implementation of an associated item to its
660 // declaration in the trait declaration.
661 let item_type = match item_type {
662 // For historical but not technical reasons, the item type of methods in
663 // trait declarations depends on whether the method is required (`TyMethod`) or
664 // provided (`Method`).
665 ItemType::Method | ItemType::TyMethod => {
666 if provided_methods.contains(&name) {
672 // For associated types and constants, no such distinction exists.
673 item_type => item_type,
676 match href(did.expect_def_id(), cx) {
677 Ok((url, ..)) => Some(format!("{}#{}.{}", url, item_type, name)),
678 // The link is broken since it points to an external crate that wasn't documented.
679 // Do not create any link in such case. This is better than falling back to a
680 // dummy anchor like `#{item_type}.{name}` representing the `id` of *this* impl item
681 // (that used to happen in older versions). Indeed, in most cases this dummy would
682 // coincide with the `id`. However, it would not always do so.
683 // In general, this dummy would be incorrect:
684 // If the type with the trait impl also had an inherent impl with an assoc. item of
685 // the *same* name as this impl item, the dummy would link to that one even though
686 // those two items are distinct!
687 // In this scenario, the actual `id` of this impl item would be
688 // `#{item_type}.{name}-{n}` for some number `n` (a disambiguator).
689 Err(HrefError::DocumentationNotBuilt) => None,
690 Err(_) => Some(format!("#{}.{}", item_type, name)),
695 // If there is no `href` for the reason explained above, simply do not render it which is valid:
696 // https://html.spec.whatwg.org/multipage/links.html#links-created-by-a-and-area-elements
697 href.map(|href| format!(" href=\"{}\"", href)).unwrap_or_default()
704 default: Option<&clean::ConstantKind>,
705 link: AssocItemLink<'_>,
711 "{extra}{vis}const <a{href} class=\"constant\">{name}</a>: {ty}",
713 vis = it.visibility.print_with_space(it.item_id, cx),
714 href = assoc_href_attr(it, link, cx),
715 name = it.name.as_ref().unwrap(),
718 if let Some(default) = default {
719 // FIXME: `.value()` uses `clean::utils::format_integer_with_underscore_sep` under the
720 // hood which adds noisy underscores and a type suffix to number literals.
721 // This hurts readability in this context especially when more complex expressions
722 // are involved and it doesn't add much of value.
723 // Find a way to print constants here without all that jazz.
724 write!(w, " = {}", default.value(cx.tcx()).unwrap_or_else(|| default.expr(cx.tcx())));
731 generics: &clean::Generics,
732 bounds: &[clean::GenericBound],
733 default: Option<&clean::Type>,
734 link: AssocItemLink<'_>,
740 "{indent}type <a{href} class=\"associatedtype\">{name}</a>{generics}",
741 indent = " ".repeat(indent),
742 href = assoc_href_attr(it, link, cx),
743 name = it.name.as_ref().unwrap(),
744 generics = generics.print(cx),
746 if !bounds.is_empty() {
747 write!(w, ": {}", print_generic_bounds(bounds, cx))
749 write!(w, "{}", print_where_clause(generics, cx, indent, false));
750 if let Some(default) = default {
751 write!(w, " = {}", default.print(cx))
760 link: AssocItemLink<'_>,
763 render_mode: RenderMode,
765 let header = meth.fn_header(cx.tcx()).expect("Trying to get header from a non-function item");
766 let name = meth.name.as_ref().unwrap();
767 let vis = meth.visibility.print_with_space(meth.item_id, cx).to_string();
768 // FIXME: Once https://github.com/rust-lang/rust/issues/67792 is implemented, we can remove
770 let constness = match render_mode {
771 RenderMode::Normal => {
772 print_constness_with_space(&header.constness, meth.const_stability(cx.tcx()))
774 RenderMode::ForDeref { .. } => "",
776 let asyncness = header.asyncness.print_with_space();
777 let unsafety = header.unsafety.print_with_space();
778 let defaultness = print_default_space(meth.is_default());
779 let abi = print_abi_with_space(header.abi).to_string();
780 let href = assoc_href_attr(meth, link, cx);
782 // NOTE: `{:#}` does not print HTML formatting, `{}` does. So `g.print` can't be reused between the length calculation and `write!`.
783 let generics_len = format!("{:#}", g.print(cx)).len();
784 let mut header_len = "fn ".len()
791 + name.as_str().len()
794 let (indent, indent_str, end_newline) = if parent == ItemType::Trait {
796 let indent_str = " ";
797 render_attributes_in_pre(w, meth, indent_str);
798 (4, indent_str, false)
800 render_attributes_in_code(w, meth);
803 w.reserve(header_len + "<a href=\"\" class=\"fnname\">{".len() + "</a>".len());
806 "{indent}{vis}{constness}{asyncness}{unsafety}{defaultness}{abi}fn <a{href} class=\"fnname\">{name}</a>\
807 {generics}{decl}{notable_traits}{where_clause}",
810 constness = constness,
811 asyncness = asyncness,
813 defaultness = defaultness,
817 generics = g.print(cx),
818 decl = d.full_print(header_len, indent, header.asyncness, cx),
819 notable_traits = notable_traits_decl(d, cx),
820 where_clause = print_where_clause(g, cx, indent, end_newline),
824 /// Writes a span containing the versions at which an item became stable and/or const-stable. For
825 /// example, if the item became stable at 1.0.0, and const-stable at 1.45.0, this function would
826 /// write a span containing "1.0.0 (const: 1.45.0)".
828 /// Returns `true` if a stability annotation was rendered.
830 /// Stability and const-stability are considered separately. If the item is unstable, no version
831 /// will be written. If the item is const-unstable, "const: unstable" will be appended to the
832 /// span, with a link to the tracking issue if present. If an item's stability or const-stability
833 /// version matches the version of its enclosing item, that version will be omitted.
835 /// Note that it is possible for an unstable function to be const-stable. In that case, the span
836 /// will include the const-stable version, but no stable version will be emitted, as a natural
837 /// consequence of the above rules.
838 fn render_stability_since_raw(
841 const_stability: Option<ConstStability>,
842 containing_ver: Option<Symbol>,
843 containing_const_ver: Option<Symbol>,
845 let stable_version = ver.filter(|inner| !inner.is_empty() && Some(*inner) != containing_ver);
847 let mut title = String::new();
848 let mut stability = String::new();
850 if let Some(ver) = stable_version {
851 stability.push_str(ver.as_str());
852 title.push_str(&format!("Stable since Rust version {}", ver));
855 let const_title_and_stability = match const_stability {
856 Some(ConstStability { level: StabilityLevel::Stable { since }, .. })
857 if Some(since) != containing_const_ver =>
859 Some((format!("const since {}", since), format!("const: {}", since)))
861 Some(ConstStability { level: StabilityLevel::Unstable { issue, .. }, feature, .. }) => {
862 let unstable = if let Some(n) = issue {
864 r#"<a href="https://github.com/rust-lang/rust/issues/{}" title="Tracking issue for {}">unstable</a>"#,
868 String::from("unstable")
871 Some((String::from("const unstable"), format!("const: {}", unstable)))
876 if let Some((const_title, const_stability)) = const_title_and_stability {
877 if !title.is_empty() {
878 title.push_str(&format!(", {}", const_title));
880 title.push_str(&const_title);
883 if !stability.is_empty() {
884 stability.push_str(&format!(" ({})", const_stability));
886 stability.push_str(&const_stability);
890 if !stability.is_empty() {
891 write!(w, r#"<span class="since" title="{}">{}</span>"#, title, stability);
894 !stability.is_empty()
897 fn render_assoc_item(
900 link: AssocItemLink<'_>,
903 render_mode: RenderMode,
906 clean::StrippedItem(..) => {}
907 clean::TyMethodItem(m) => {
908 assoc_method(w, item, &m.generics, &m.decl, link, parent, cx, render_mode)
910 clean::MethodItem(m, _) => {
911 assoc_method(w, item, &m.generics, &m.decl, link, parent, cx, render_mode)
913 kind @ (clean::TyAssocConstItem(ty) | clean::AssocConstItem(ty, _)) => assoc_const(
918 clean::TyAssocConstItem(_) => None,
919 clean::AssocConstItem(_, default) => Some(default),
923 if parent == ItemType::Trait { " " } else { "" },
926 clean::TyAssocTypeItem(ref generics, ref bounds) => assoc_type(
933 if parent == ItemType::Trait { 4 } else { 0 },
936 clean::AssocTypeItem(ref ty, ref bounds) => assoc_type(
941 Some(ty.item_type.as_ref().unwrap_or(&ty.type_)),
943 if parent == ItemType::Trait { 4 } else { 0 },
946 _ => panic!("render_assoc_item called on non-associated-item"),
950 const ALLOWED_ATTRIBUTES: &[Symbol] =
951 &[sym::export_name, sym::link_section, sym::no_mangle, sym::repr, sym::non_exhaustive];
953 fn attributes(it: &clean::Item) -> Vec<String> {
958 if ALLOWED_ATTRIBUTES.contains(&attr.name_or_empty()) {
960 pprust::attribute_to_string(attr)
972 // When an attribute is rendered inside a `<pre>` tag, it is formatted using
973 // a whitespace prefix and newline.
974 fn render_attributes_in_pre(w: &mut Buffer, it: &clean::Item, prefix: &str) {
975 for a in attributes(it) {
976 writeln!(w, "{}{}", prefix, a);
980 // When an attribute is rendered inside a <code> tag, it is formatted using
981 // a div to produce a newline after it.
982 fn render_attributes_in_code(w: &mut Buffer, it: &clean::Item) {
983 for a in attributes(it) {
984 write!(w, "<div class=\"code-attribute\">{}</div>", a);
988 #[derive(Copy, Clone)]
989 enum AssocItemLink<'a> {
990 Anchor(Option<&'a str>),
991 GotoSource(ItemId, &'a FxHashSet<Symbol>),
994 impl<'a> AssocItemLink<'a> {
995 fn anchor(&self, id: &'a str) -> Self {
997 AssocItemLink::Anchor(_) => AssocItemLink::Anchor(Some(id)),
1003 fn render_assoc_items(
1005 cx: &mut Context<'_>,
1006 containing_item: &clean::Item,
1008 what: AssocItemRender<'_>,
1010 let mut derefs = FxHashSet::default();
1012 render_assoc_items_inner(w, cx, containing_item, it, what, &mut derefs)
1015 fn render_assoc_items_inner(
1017 cx: &mut Context<'_>,
1018 containing_item: &clean::Item,
1020 what: AssocItemRender<'_>,
1021 derefs: &mut FxHashSet<DefId>,
1023 info!("Documenting associated items of {:?}", containing_item.name);
1024 let shared = Rc::clone(&cx.shared);
1025 let cache = &shared.cache;
1026 let Some(v) = cache.impls.get(&it) else { return };
1027 let (non_trait, traits): (Vec<_>, _) = v.iter().partition(|i| i.inner_impl().trait_.is_none());
1028 if !non_trait.is_empty() {
1029 let mut tmp_buf = Buffer::empty_from(w);
1030 let (render_mode, id) = match what {
1031 AssocItemRender::All => {
1033 "<h2 id=\"implementations\" class=\"small-section-header\">\
1035 <a href=\"#implementations\" class=\"anchor\"></a>\
1038 (RenderMode::Normal, "implementations-list".to_owned())
1040 AssocItemRender::DerefFor { trait_, type_, deref_mut_ } => {
1042 cx.derive_id(small_url_encode(format!("deref-methods-{:#}", type_.print(cx))));
1043 if let Some(def_id) = type_.def_id(cx.cache()) {
1044 cx.deref_id_map.insert(def_id, id.clone());
1048 "<h2 id=\"{id}\" class=\"small-section-header\">\
1049 <span>Methods from {trait_}<Target = {type_}></span>\
1050 <a href=\"#{id}\" class=\"anchor\"></a>\
1053 trait_ = trait_.print(cx),
1054 type_ = type_.print(cx),
1056 (RenderMode::ForDeref { mut_: deref_mut_ }, cx.derive_id(id))
1059 let mut impls_buf = Buffer::empty_from(w);
1060 for i in &non_trait {
1066 AssocItemLink::Anchor(None),
1070 ImplRenderingParameters {
1071 show_def_docs: true,
1072 is_on_foreign_type: false,
1073 show_default_items: true,
1074 show_non_assoc_items: true,
1075 toggle_open_by_default: true,
1079 if !impls_buf.is_empty() {
1080 w.push_buffer(tmp_buf);
1081 write!(w, "<div id=\"{}\">", id);
1082 w.push_buffer(impls_buf);
1083 w.write_str("</div>");
1087 if !traits.is_empty() {
1089 traits.iter().find(|t| t.trait_did() == cx.tcx().lang_items().deref_trait());
1090 if let Some(impl_) = deref_impl {
1092 traits.iter().any(|t| t.trait_did() == cx.tcx().lang_items().deref_mut_trait());
1093 render_deref_methods(w, cx, impl_, containing_item, has_deref_mut, derefs);
1096 // If we were already one level into rendering deref methods, we don't want to render
1097 // anything after recursing into any further deref methods above.
1098 if let AssocItemRender::DerefFor { .. } = what {
1102 let (synthetic, concrete): (Vec<&&Impl>, Vec<&&Impl>) =
1103 traits.iter().partition(|t| t.inner_impl().kind.is_auto());
1104 let (blanket_impl, concrete): (Vec<&&Impl>, _) =
1105 concrete.into_iter().partition(|t| t.inner_impl().kind.is_blanket());
1107 let mut impls = Buffer::empty_from(w);
1108 render_impls(cx, &mut impls, &concrete, containing_item, true);
1109 let impls = impls.into_inner();
1110 if !impls.is_empty() {
1113 "<h2 id=\"trait-implementations\" class=\"small-section-header\">\
1114 Trait Implementations\
1115 <a href=\"#trait-implementations\" class=\"anchor\"></a>\
1117 <div id=\"trait-implementations-list\">{}</div>",
1122 if !synthetic.is_empty() {
1124 "<h2 id=\"synthetic-implementations\" class=\"small-section-header\">\
1125 Auto Trait Implementations\
1126 <a href=\"#synthetic-implementations\" class=\"anchor\"></a>\
1128 <div id=\"synthetic-implementations-list\">",
1130 render_impls(cx, w, &synthetic, containing_item, false);
1131 w.write_str("</div>");
1134 if !blanket_impl.is_empty() {
1136 "<h2 id=\"blanket-implementations\" class=\"small-section-header\">\
1137 Blanket Implementations\
1138 <a href=\"#blanket-implementations\" class=\"anchor\"></a>\
1140 <div id=\"blanket-implementations-list\">",
1142 render_impls(cx, w, &blanket_impl, containing_item, false);
1143 w.write_str("</div>");
1148 fn render_deref_methods(
1150 cx: &mut Context<'_>,
1152 container_item: &clean::Item,
1154 derefs: &mut FxHashSet<DefId>,
1156 let cache = cx.cache();
1157 let deref_type = impl_.inner_impl().trait_.as_ref().unwrap();
1158 let (target, real_target) = impl_
1162 .find_map(|item| match *item.kind {
1163 clean::AssocTypeItem(ref t, _) => Some(match *t {
1164 clean::Typedef { item_type: Some(ref type_), .. } => (type_, &t.type_),
1165 _ => (&t.type_, &t.type_),
1169 .expect("Expected associated type binding");
1170 debug!("Render deref methods for {:#?}, target {:#?}", impl_.inner_impl().for_, target);
1172 AssocItemRender::DerefFor { trait_: deref_type, type_: real_target, deref_mut_: deref_mut };
1173 if let Some(did) = target.def_id(cache) {
1174 if let Some(type_did) = impl_.inner_impl().for_.def_id(cache) {
1175 // `impl Deref<Target = S> for S`
1176 if did == type_did || !derefs.insert(did) {
1177 // Avoid infinite cycles
1181 render_assoc_items_inner(w, cx, container_item, did, what, derefs);
1182 } else if let Some(prim) = target.primitive_type() {
1183 if let Some(&did) = cache.primitive_locations.get(&prim) {
1184 render_assoc_items_inner(w, cx, container_item, did, what, derefs);
1189 fn should_render_item(item: &clean::Item, deref_mut_: bool, tcx: TyCtxt<'_>) -> bool {
1190 let self_type_opt = match *item.kind {
1191 clean::MethodItem(ref method, _) => method.decl.self_type(),
1192 clean::TyMethodItem(ref method) => method.decl.self_type(),
1196 if let Some(self_ty) = self_type_opt {
1197 let (by_mut_ref, by_box, by_value) = match self_ty {
1198 SelfTy::SelfBorrowed(_, mutability)
1199 | SelfTy::SelfExplicit(clean::BorrowedRef { mutability, .. }) => {
1200 (mutability == Mutability::Mut, false, false)
1202 SelfTy::SelfExplicit(clean::Type::Path { path }) => {
1203 (false, Some(path.def_id()) == tcx.lang_items().owned_box(), false)
1205 SelfTy::SelfValue => (false, false, true),
1206 _ => (false, false, false),
1209 (deref_mut_ || !by_mut_ref) && !by_box && !by_value
1215 fn notable_traits_decl(decl: &clean::FnDecl, cx: &Context<'_>) -> String {
1216 let mut out = Buffer::html();
1218 if let Some((did, ty)) = decl.output.as_return().and_then(|t| Some((t.def_id(cx.cache())?, t)))
1220 if let Some(impls) = cx.cache().impls.get(&did) {
1222 let impl_ = i.inner_impl();
1223 if !impl_.for_.without_borrowed_ref().is_same(ty.without_borrowed_ref(), cx.cache())
1225 // Two different types might have the same did,
1226 // without actually being the same.
1229 if let Some(trait_) = &impl_.trait_ {
1230 let trait_did = trait_.def_id();
1232 if cx.cache().traits.get(&trait_did).map_or(false, |t| t.is_notable) {
1236 "<span class=\"notable\">Notable traits for {}</span>\
1237 <code class=\"content\">",
1238 impl_.for_.print(cx)
1242 //use the "where" class here to make it small
1245 "<span class=\"where fmt-newline\">{}</span>",
1246 impl_.print(false, cx)
1248 for it in &impl_.items {
1249 if let clean::AssocTypeItem(ref tydef, ref _bounds) = *it.kind {
1250 out.push_str("<span class=\"where fmt-newline\"> ");
1251 let empty_set = FxHashSet::default();
1253 AssocItemLink::GotoSource(trait_did.into(), &empty_set);
1258 &[], // intentionally leaving out bounds
1264 out.push_str(";</span>");
1273 if !out.is_empty() {
1276 "<span class=\"notable-traits\"><span class=\"notable-traits-tooltip\">ⓘ\
1277 <span class=\"notable-traits-tooltiptext\"><span class=\"docblock\">",
1279 out.push_str("</code></span></span></span></span>");
1285 #[derive(Clone, Copy, Debug)]
1286 struct ImplRenderingParameters {
1287 show_def_docs: bool,
1288 is_on_foreign_type: bool,
1289 show_default_items: bool,
1290 /// Whether or not to show methods.
1291 show_non_assoc_items: bool,
1292 toggle_open_by_default: bool,
1297 cx: &mut Context<'_>,
1299 parent: &clean::Item,
1300 link: AssocItemLink<'_>,
1301 render_mode: RenderMode,
1302 use_absolute: Option<bool>,
1304 rendering_params: ImplRenderingParameters,
1306 let shared = Rc::clone(&cx.shared);
1307 let cache = &shared.cache;
1308 let traits = &cache.traits;
1309 let trait_ = i.trait_did().map(|did| &traits[&did]);
1310 let mut close_tags = String::new();
1312 // For trait implementations, the `interesting` output contains all methods that have doc
1313 // comments, and the `boring` output contains all methods that do not. The distinction is
1314 // used to allow hiding the boring methods.
1315 // `containing_item` is used for rendering stability info. If the parent is a trait impl,
1316 // `containing_item` will the grandparent, since trait impls can't have stability attached.
1318 boring: &mut Buffer,
1319 interesting: &mut Buffer,
1320 cx: &mut Context<'_>,
1322 parent: &clean::Item,
1323 containing_item: &clean::Item,
1324 link: AssocItemLink<'_>,
1325 render_mode: RenderMode,
1326 is_default_item: bool,
1327 trait_: Option<&clean::Trait>,
1328 rendering_params: ImplRenderingParameters,
1330 let item_type = item.type_();
1331 let name = item.name.as_ref().unwrap();
1333 let render_method_item = rendering_params.show_non_assoc_items
1334 && match render_mode {
1335 RenderMode::Normal => true,
1336 RenderMode::ForDeref { mut_: deref_mut_ } => {
1337 should_render_item(item, deref_mut_, cx.tcx())
1341 let in_trait_class = if trait_.is_some() { " trait-impl" } else { "" };
1343 let mut doc_buffer = Buffer::empty_from(boring);
1344 let mut info_buffer = Buffer::empty_from(boring);
1345 let mut short_documented = true;
1347 if render_method_item {
1348 if !is_default_item {
1349 if let Some(t) = trait_ {
1350 // The trait item may have been stripped so we might not
1351 // find any documentation or stability for it.
1352 if let Some(it) = t.items.iter().find(|i| i.name == item.name) {
1353 // We need the stability of the item from the trait
1354 // because impls can't have a stability.
1355 if item.doc_value().is_some() {
1356 document_item_info(&mut info_buffer, cx, it, Some(parent));
1357 document_full(&mut doc_buffer, item, cx, HeadingOffset::H5);
1358 short_documented = false;
1360 // In case the item isn't documented,
1361 // provide short documentation from the trait.
1368 rendering_params.show_def_docs,
1373 document_item_info(&mut info_buffer, cx, item, Some(parent));
1374 if rendering_params.show_def_docs {
1375 document_full(&mut doc_buffer, item, cx, HeadingOffset::H5);
1376 short_documented = false;
1386 rendering_params.show_def_docs,
1390 let w = if short_documented && trait_.is_some() { interesting } else { boring };
1392 let toggled = !doc_buffer.is_empty();
1394 let method_toggle_class =
1395 if item_type == ItemType::Method { " method-toggle" } else { "" };
1396 write!(w, "<details class=\"rustdoc-toggle{}\" open><summary>", method_toggle_class);
1399 clean::MethodItem(..) | clean::TyMethodItem(_) => {
1400 // Only render when the method is not static or we allow static methods
1401 if render_method_item {
1402 let id = cx.derive_id(format!("{}.{}", item_type, name));
1403 let source_id = trait_
1404 .and_then(|trait_| {
1405 trait_.items.iter().find(|item| {
1406 item.name.map(|n| n.as_str().eq(name.as_str())).unwrap_or(false)
1409 .map(|item| format!("{}.{}", item.type_(), name));
1412 "<section id=\"{}\" class=\"{}{} has-srclink\">",
1413 id, item_type, in_trait_class,
1415 render_rightside(w, cx, item, containing_item, render_mode);
1416 write!(w, "<a href=\"#{}\" class=\"anchor\"></a>", id);
1417 w.write_str("<h4 class=\"code-header\">");
1421 link.anchor(source_id.as_ref().unwrap_or(&id)),
1426 w.write_str("</h4>");
1427 w.write_str("</section>");
1430 kind @ (clean::TyAssocConstItem(ty) | clean::AssocConstItem(ty, _)) => {
1431 let source_id = format!("{}.{}", item_type, name);
1432 let id = cx.derive_id(source_id.clone());
1435 "<section id=\"{}\" class=\"{}{} has-srclink\">",
1436 id, item_type, in_trait_class
1438 render_rightside(w, cx, item, containing_item, render_mode);
1439 write!(w, "<a href=\"#{}\" class=\"anchor\"></a>", id);
1440 w.write_str("<h4 class=\"code-header\">");
1446 clean::TyAssocConstItem(_) => None,
1447 clean::AssocConstItem(_, default) => Some(default),
1448 _ => unreachable!(),
1450 link.anchor(if trait_.is_some() { &source_id } else { &id }),
1454 w.write_str("</h4>");
1455 w.write_str("</section>");
1457 clean::TyAssocTypeItem(generics, bounds) => {
1458 let source_id = format!("{}.{}", item_type, name);
1459 let id = cx.derive_id(source_id.clone());
1460 write!(w, "<section id=\"{}\" class=\"{}{}\">", id, item_type, in_trait_class);
1461 write!(w, "<a href=\"#{}\" class=\"anchor\"></a>", id);
1462 w.write_str("<h4 class=\"code-header\">");
1469 link.anchor(if trait_.is_some() { &source_id } else { &id }),
1473 w.write_str("</h4>");
1474 w.write_str("</section>");
1476 clean::AssocTypeItem(tydef, _bounds) => {
1477 let source_id = format!("{}.{}", item_type, name);
1478 let id = cx.derive_id(source_id.clone());
1481 "<section id=\"{}\" class=\"{}{} has-srclink\">",
1482 id, item_type, in_trait_class
1484 write!(w, "<a href=\"#{}\" class=\"anchor\"></a>", id);
1485 w.write_str("<h4 class=\"code-header\">");
1490 &[], // intentionally leaving out bounds
1491 Some(tydef.item_type.as_ref().unwrap_or(&tydef.type_)),
1492 link.anchor(if trait_.is_some() { &source_id } else { &id }),
1496 w.write_str("</h4>");
1497 w.write_str("</section>");
1499 clean::StrippedItem(..) => return,
1500 _ => panic!("can't make docs for trait item with name {:?}", item.name),
1503 w.push_buffer(info_buffer);
1505 w.write_str("</summary>");
1506 w.push_buffer(doc_buffer);
1507 w.push_str("</details>");
1511 let mut impl_items = Buffer::empty_from(w);
1512 let mut default_impl_items = Buffer::empty_from(w);
1514 for trait_item in &i.inner_impl().items {
1516 &mut default_impl_items,
1520 if trait_.is_some() { &i.impl_item } else { parent },
1525 trait_.map(|t| &t.trait_),
1530 fn render_default_items(
1531 boring: &mut Buffer,
1532 interesting: &mut Buffer,
1533 cx: &mut Context<'_>,
1536 parent: &clean::Item,
1537 containing_item: &clean::Item,
1538 render_mode: RenderMode,
1539 rendering_params: ImplRenderingParameters,
1541 for trait_item in &t.items {
1542 let n = trait_item.name;
1543 if i.items.iter().any(|m| m.name == n) {
1546 let did = i.trait_.as_ref().unwrap().def_id();
1547 let provided_methods = i.provided_trait_methods(cx.tcx());
1548 let assoc_link = AssocItemLink::GotoSource(did.into(), &provided_methods);
1566 // If we've implemented a trait, then also emit documentation for all
1567 // default items which weren't overridden in the implementation block.
1568 // We don't emit documentation for default items if they appear in the
1569 // Implementations on Foreign Types or Implementors sections.
1570 if rendering_params.show_default_items {
1571 if let Some(t) = trait_ {
1572 render_default_items(
1573 &mut default_impl_items,
1585 if render_mode == RenderMode::Normal {
1586 let toggled = !(impl_items.is_empty() && default_impl_items.is_empty());
1588 close_tags.insert_str(0, "</details>");
1591 "<details class=\"rustdoc-toggle implementors-toggle\"{}>",
1592 if rendering_params.toggle_open_by_default { " open" } else { "" }
1594 write!(w, "<summary>")
1596 render_impl_summary(
1602 rendering_params.show_def_docs,
1604 rendering_params.is_on_foreign_type,
1608 write!(w, "</summary>")
1611 if let Some(ref dox) = i.impl_item.collapsed_doc_value() {
1612 if trait_.is_none() && i.inner_impl().items.is_empty() {
1614 "<div class=\"item-info\">\
1615 <div class=\"stab empty-impl\">This impl block contains no items.</div>
1621 "<div class=\"docblock\">{}</div>",
1624 links: &i.impl_item.links(cx),
1625 ids: &mut cx.id_map,
1626 error_codes: cx.shared.codes,
1627 edition: cx.shared.edition(),
1628 playground: &cx.shared.playground,
1629 heading_offset: HeadingOffset::H4
1635 if !default_impl_items.is_empty() || !impl_items.is_empty() {
1636 w.write_str("<div class=\"impl-items\">");
1637 w.push_buffer(default_impl_items);
1638 w.push_buffer(impl_items);
1639 close_tags.insert_str(0, "</div>");
1641 w.write_str(&close_tags);
1644 // Render the items that appear on the right side of methods, impls, and
1645 // associated types. For example "1.0.0 (const: 1.39.0) · source".
1646 fn render_rightside(
1650 containing_item: &clean::Item,
1651 render_mode: RenderMode,
1655 // FIXME: Once https://github.com/rust-lang/rust/issues/67792 is implemented, we can remove
1657 let (const_stability, const_stable_since) = match render_mode {
1658 RenderMode::Normal => (item.const_stability(tcx), containing_item.const_stable_since(tcx)),
1659 RenderMode::ForDeref { .. } => (None, None),
1662 let mut rightside = Buffer::new();
1663 let has_stability = render_stability_since_raw(
1665 item.stable_since(tcx),
1667 containing_item.stable_since(tcx),
1670 let mut srclink = Buffer::empty_from(w);
1671 write_srclink(cx, item, &mut srclink);
1672 if has_stability && !srclink.is_empty() {
1673 rightside.write_str(" · ");
1675 rightside.push_buffer(srclink);
1676 if !rightside.is_empty() {
1677 write!(w, "<span class=\"rightside\">{}</span>", rightside.into_inner());
1681 pub(crate) fn render_impl_summary(
1683 cx: &mut Context<'_>,
1685 parent: &clean::Item,
1686 containing_item: &clean::Item,
1687 show_def_docs: bool,
1688 use_absolute: Option<bool>,
1689 is_on_foreign_type: bool,
1690 // This argument is used to reference same type with different paths to avoid duplication
1691 // in documentation pages for trait with automatic implementations like "Send" and "Sync".
1694 let id = cx.derive_id(match i.inner_impl().trait_ {
1696 if is_on_foreign_type {
1697 get_id_for_impl_on_foreign_type(&i.inner_impl().for_, t, cx)
1699 format!("impl-{}", small_url_encode(format!("{:#}", t.print(cx))))
1702 None => "impl".to_string(),
1704 let aliases = if aliases.is_empty() {
1707 format!(" data-aliases=\"{}\"", aliases.join(","))
1709 write!(w, "<section id=\"{}\" class=\"impl has-srclink\"{}>", id, aliases);
1710 render_rightside(w, cx, &i.impl_item, containing_item, RenderMode::Normal);
1711 write!(w, "<a href=\"#{}\" class=\"anchor\"></a>", id);
1712 write!(w, "<h3 class=\"code-header in-band\">");
1714 if let Some(use_absolute) = use_absolute {
1715 write!(w, "{}", i.inner_impl().print(use_absolute, cx));
1717 for it in &i.inner_impl().items {
1718 if let clean::AssocTypeItem(ref tydef, ref _bounds) = *it.kind {
1719 w.write_str("<span class=\"where fmt-newline\"> ");
1724 &[], // intentionally leaving out bounds
1726 AssocItemLink::Anchor(None),
1730 w.write_str(";</span>");
1735 write!(w, "{}", i.inner_impl().print(false, cx));
1739 let is_trait = i.inner_impl().trait_.is_some();
1741 if let Some(portability) = portability(&i.impl_item, Some(parent)) {
1742 write!(w, "<span class=\"item-info\">{}</span>", portability);
1746 w.write_str("</section>");
1749 fn print_sidebar(cx: &Context<'_>, it: &clean::Item, buffer: &mut Buffer) {
1752 || it.is_primitive()
1760 "<h2 class=\"location\"><a href=\"#\">{}{}</a></h2>",
1762 clean::ModuleItem(..) =>
1770 it.name.as_ref().unwrap()
1774 buffer.write_str("<div class=\"sidebar-elems\">");
1776 write!(buffer, "<div class=\"block\"><ul>");
1777 if let Some(ref version) = cx.cache().crate_version {
1778 write!(buffer, "<li class=\"version\">Version {}</li>", Escape(version));
1780 write!(buffer, "<li><a id=\"all-types\" href=\"all.html\">All Items</a></li>");
1781 buffer.write_str("</ul></div>");
1785 clean::StructItem(ref s) => sidebar_struct(cx, buffer, it, s),
1786 clean::TraitItem(ref t) => sidebar_trait(cx, buffer, it, t),
1787 clean::PrimitiveItem(_) => sidebar_primitive(cx, buffer, it),
1788 clean::UnionItem(ref u) => sidebar_union(cx, buffer, it, u),
1789 clean::EnumItem(ref e) => sidebar_enum(cx, buffer, it, e),
1790 clean::TypedefItem(_) => sidebar_typedef(cx, buffer, it),
1791 clean::ModuleItem(ref m) => sidebar_module(buffer, &m.items),
1792 clean::ForeignTypeItem => sidebar_foreign_type(cx, buffer, it),
1796 // The sidebar is designed to display sibling functions, modules and
1797 // other miscellaneous information. since there are lots of sibling
1798 // items (and that causes quadratic growth in large modules),
1799 // we refactor common parts into a shared JavaScript file per module.
1800 // still, we don't move everything into JS because we want to preserve
1801 // as much HTML as possible in order to allow non-JS-enabled browsers
1802 // to navigate the documentation (though slightly inefficiently).
1805 let path: String = cx.current.iter().map(|s| s.as_str()).intersperse("::").collect();
1807 write!(buffer, "<h2 class=\"location\"><a href=\"index.html\">In {}</a></h2>", path);
1810 // Closes sidebar-elems div.
1811 buffer.write_str("</div>");
1814 fn get_next_url(used_links: &mut FxHashSet<String>, url: String) -> String {
1815 if used_links.insert(url.clone()) {
1819 while !used_links.insert(format!("{}-{}", url, add)) {
1822 format!("{}-{}", url, add)
1825 struct SidebarLink {
1830 impl fmt::Display for SidebarLink {
1831 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1832 write!(f, "<a href=\"#{}\">{}</a>", self.url, self.name)
1836 impl PartialEq for SidebarLink {
1837 fn eq(&self, other: &Self) -> bool {
1838 self.url == other.url
1842 impl Eq for SidebarLink {}
1844 impl PartialOrd for SidebarLink {
1845 fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
1846 Some(self.cmp(other))
1850 impl Ord for SidebarLink {
1851 fn cmp(&self, other: &Self) -> std::cmp::Ordering {
1852 self.url.cmp(&other.url)
1859 used_links: &mut FxHashSet<String>,
1862 ) -> Vec<SidebarLink> {
1865 .filter_map(|item| match item.name {
1866 Some(name) if !name.is_empty() && item.is_method() => {
1867 if !for_deref || should_render_item(item, deref_mut, tcx) {
1870 url: get_next_url(used_links, format!("{}.{}", ItemType::Method, name)),
1878 .collect::<Vec<_>>()
1881 fn get_associated_constants(
1883 used_links: &mut FxHashSet<String>,
1884 ) -> Vec<SidebarLink> {
1887 .filter_map(|item| match item.name {
1888 Some(name) if !name.is_empty() && item.is_associated_const() => Some(SidebarLink {
1890 url: get_next_url(used_links, format!("{}.{}", ItemType::AssocConst, name)),
1894 .collect::<Vec<_>>()
1897 // The point is to url encode any potential character from a type with genericity.
1898 fn small_url_encode(s: String) -> String {
1899 let mut st = String::new();
1900 let mut last_match = 0;
1901 for (idx, c) in s.char_indices() {
1902 let escaped = match c {
1918 st += &s[last_match..idx];
1920 // NOTE: we only expect single byte characters here - which is fine as long as we
1921 // only match single byte characters
1922 last_match = idx + 1;
1925 if last_match != 0 {
1926 st += &s[last_match..];
1933 fn sidebar_assoc_items(cx: &Context<'_>, out: &mut Buffer, it: &clean::Item) {
1934 let did = it.item_id.expect_def_id();
1935 let cache = cx.cache();
1937 if let Some(v) = cache.impls.get(&did) {
1938 let mut used_links = FxHashSet::default();
1939 let mut id_map = IdMap::new();
1942 let used_links_bor = &mut used_links;
1943 let mut assoc_consts = v
1945 .filter(|i| i.inner_impl().trait_.is_none())
1946 .flat_map(|i| get_associated_constants(i.inner_impl(), used_links_bor))
1947 .collect::<Vec<_>>();
1948 if !assoc_consts.is_empty() {
1949 // We want links' order to be reproducible so we don't use unstable sort.
1950 assoc_consts.sort();
1952 print_sidebar_block(
1955 "Associated Constants",
1956 assoc_consts.iter(),
1961 .filter(|i| i.inner_impl().trait_.is_none())
1962 .flat_map(|i| get_methods(i.inner_impl(), false, used_links_bor, false, cx.tcx()))
1963 .collect::<Vec<_>>();
1964 if !methods.is_empty() {
1965 // We want links' order to be reproducible so we don't use unstable sort.
1968 print_sidebar_block(out, "implementations", "Methods", methods.iter());
1972 if v.iter().any(|i| i.inner_impl().trait_.is_some()) {
1973 if let Some(impl_) =
1974 v.iter().find(|i| i.trait_did() == cx.tcx().lang_items().deref_trait())
1976 let mut derefs = FxHashSet::default();
1978 sidebar_deref_methods(cx, out, impl_, v, &mut derefs);
1981 let format_impls = |impls: Vec<&Impl>, id_map: &mut IdMap| {
1982 let mut links = FxHashSet::default();
1987 if let Some(ref i) = it.inner_impl().trait_ {
1988 let i_display = format!("{:#}", i.print(cx));
1989 let out = Escape(&i_display);
1991 id_map.derive(small_url_encode(format!("impl-{:#}", i.print(cx))));
1992 let prefix = match it.inner_impl().polarity {
1993 ty::ImplPolarity::Positive | ty::ImplPolarity::Reservation => "",
1994 ty::ImplPolarity::Negative => "!",
1997 format!("<a href=\"#{}\">{}{}</a>", encoded, prefix, out);
1998 if links.insert(generated.clone()) { Some(generated) } else { None }
2003 .collect::<Vec<String>>();
2008 let (synthetic, concrete): (Vec<&Impl>, Vec<&Impl>) =
2009 v.iter().partition::<Vec<_>, _>(|i| i.inner_impl().kind.is_auto());
2010 let (blanket_impl, concrete): (Vec<&Impl>, Vec<&Impl>) =
2011 concrete.into_iter().partition::<Vec<_>, _>(|i| i.inner_impl().kind.is_blanket());
2013 let concrete_format = format_impls(concrete, &mut id_map);
2014 let synthetic_format = format_impls(synthetic, &mut id_map);
2015 let blanket_format = format_impls(blanket_impl, &mut id_map);
2017 if !concrete_format.is_empty() {
2018 print_sidebar_block(
2020 "trait-implementations",
2021 "Trait Implementations",
2022 concrete_format.iter(),
2026 if !synthetic_format.is_empty() {
2027 print_sidebar_block(
2029 "synthetic-implementations",
2030 "Auto Trait Implementations",
2031 synthetic_format.iter(),
2035 if !blanket_format.is_empty() {
2036 print_sidebar_block(
2038 "blanket-implementations",
2039 "Blanket Implementations",
2040 blanket_format.iter(),
2047 fn sidebar_deref_methods(
2052 derefs: &mut FxHashSet<DefId>,
2056 debug!("found Deref: {:?}", impl_);
2057 if let Some((target, real_target)) =
2058 impl_.inner_impl().items.iter().find_map(|item| match *item.kind {
2059 clean::AssocTypeItem(ref t, _) => Some(match *t {
2060 clean::Typedef { item_type: Some(ref type_), .. } => (type_, &t.type_),
2061 _ => (&t.type_, &t.type_),
2066 debug!("found target, real_target: {:?} {:?}", target, real_target);
2067 if let Some(did) = target.def_id(c) {
2068 if let Some(type_did) = impl_.inner_impl().for_.def_id(c) {
2069 // `impl Deref<Target = S> for S`
2070 if did == type_did || !derefs.insert(did) {
2071 // Avoid infinite cycles
2076 let deref_mut = v.iter().any(|i| i.trait_did() == cx.tcx().lang_items().deref_mut_trait());
2077 let inner_impl = target
2080 target.primitive_type().and_then(|prim| c.primitive_locations.get(&prim).cloned())
2082 .and_then(|did| c.impls.get(&did));
2083 if let Some(impls) = inner_impl {
2084 debug!("found inner_impl: {:?}", impls);
2085 let mut used_links = FxHashSet::default();
2088 .filter(|i| i.inner_impl().trait_.is_none())
2090 get_methods(i.inner_impl(), true, &mut used_links, deref_mut, cx.tcx())
2092 .collect::<Vec<_>>();
2093 if !ret.is_empty() {
2094 let id = if let Some(target_def_id) = real_target.def_id(c) {
2095 cx.deref_id_map.get(&target_def_id).expect("Deref section without derived id")
2099 let title = format!(
2100 "Methods from {}<Target={}>",
2101 Escape(&format!("{:#}", impl_.inner_impl().trait_.as_ref().unwrap().print(cx))),
2102 Escape(&format!("{:#}", real_target.print(cx))),
2104 // We want links' order to be reproducible so we don't use unstable sort.
2106 print_sidebar_block(out, id, &title, ret.iter());
2110 // Recurse into any further impls that might exist for `target`
2111 if let Some(target_did) = target.def_id(c) {
2112 if let Some(target_impls) = c.impls.get(&target_did) {
2113 if let Some(target_deref_impl) = target_impls.iter().find(|i| {
2117 .map(|t| Some(t.def_id()) == cx.tcx().lang_items().deref_trait())
2120 sidebar_deref_methods(cx, out, target_deref_impl, target_impls, derefs);
2127 fn sidebar_struct(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, s: &clean::Struct) {
2128 let mut sidebar = Buffer::new();
2129 let fields = get_struct_fields_name(&s.fields);
2131 if !fields.is_empty() {
2132 match s.struct_type {
2133 CtorKind::Fictive => {
2134 print_sidebar_block(&mut sidebar, "fields", "Fields", fields.iter());
2136 CtorKind::Fn => print_sidebar_title(&mut sidebar, "fields", "Tuple Fields"),
2137 CtorKind::Const => {}
2141 sidebar_assoc_items(cx, &mut sidebar, it);
2143 if !sidebar.is_empty() {
2144 write!(buf, "<section>{}</section>", sidebar.into_inner());
2148 fn get_id_for_impl_on_foreign_type(
2150 trait_: &clean::Path,
2153 small_url_encode(format!("impl-{:#}-for-{:#}", trait_.print(cx), for_.print(cx)))
2156 fn extract_for_impl_name(item: &clean::Item, cx: &Context<'_>) -> Option<(String, String)> {
2158 clean::ItemKind::ImplItem(ref i) => {
2159 i.trait_.as_ref().map(|trait_| {
2160 // Alternative format produces no URLs,
2161 // so this parameter does nothing.
2163 format!("{:#}", i.for_.print(cx)),
2164 get_id_for_impl_on_foreign_type(&i.for_, trait_, cx),
2172 /// Don't call this function directly!!! Use `print_sidebar_title` or `print_sidebar_block` instead!
2173 fn print_sidebar_title_inner(buf: &mut Buffer, id: &str, title: &str) {
2176 "<h3 class=\"sidebar-title\">\
2177 <a href=\"#{}\">{}</a>\
2183 fn print_sidebar_title(buf: &mut Buffer, id: &str, title: &str) {
2184 buf.push_str("<div class=\"block\">");
2185 print_sidebar_title_inner(buf, id, title);
2186 buf.push_str("</div>");
2189 fn print_sidebar_block(
2193 items: impl Iterator<Item = impl fmt::Display>,
2195 buf.push_str("<div class=\"block\">");
2196 print_sidebar_title_inner(buf, id, title);
2197 buf.push_str("<ul>");
2199 write!(buf, "<li>{}</li>", item);
2201 buf.push_str("</ul></div>");
2204 fn sidebar_trait(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, t: &clean::Trait) {
2205 buf.write_str("<section>");
2207 fn print_sidebar_section(
2209 items: &[clean::Item],
2212 filter: impl Fn(&clean::Item) -> bool,
2213 mapper: impl Fn(&str) -> String,
2215 let mut items: Vec<&str> = items
2217 .filter_map(|m| match m.name {
2218 Some(ref name) if filter(m) => Some(name.as_str()),
2221 .collect::<Vec<_>>();
2223 if !items.is_empty() {
2224 items.sort_unstable();
2225 print_sidebar_block(out, id, title, items.into_iter().map(mapper));
2229 print_sidebar_section(
2232 "required-associated-types",
2233 "Required Associated Types",
2234 |m| m.is_ty_associated_type(),
2235 |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::AssocType),
2238 print_sidebar_section(
2241 "provided-associated-types",
2242 "Provided Associated Types",
2243 |m| m.is_associated_type(),
2244 |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::AssocType),
2247 print_sidebar_section(
2250 "required-associated-consts",
2251 "Required Associated Constants",
2252 |m| m.is_ty_associated_const(),
2253 |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::AssocConst),
2256 print_sidebar_section(
2259 "provided-associated-consts",
2260 "Provided Associated Constants",
2261 |m| m.is_associated_const(),
2262 |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::AssocConst),
2265 print_sidebar_section(
2270 |m| m.is_ty_method(),
2271 |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::TyMethod),
2274 print_sidebar_section(
2280 |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::Method),
2283 if let Some(implementors) = cx.cache().implementors.get(&it.item_id.expect_def_id()) {
2284 let mut res = implementors
2286 .filter(|i| !i.is_on_local_type(cx))
2287 .filter_map(|i| extract_for_impl_name(&i.impl_item, cx))
2288 .collect::<Vec<_>>();
2290 if !res.is_empty() {
2292 print_sidebar_block(
2295 "Implementations on Foreign Types",
2296 res.iter().map(|(name, id)| format!("<a href=\"#{}\">{}</a>", id, Escape(name))),
2301 sidebar_assoc_items(cx, buf, it);
2303 print_sidebar_title(buf, "implementors", "Implementors");
2305 print_sidebar_title(buf, "synthetic-implementors", "Auto Implementors");
2308 buf.push_str("</section>")
2311 fn sidebar_primitive(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item) {
2312 let mut sidebar = Buffer::new();
2313 sidebar_assoc_items(cx, &mut sidebar, it);
2315 if !sidebar.is_empty() {
2316 write!(buf, "<section>{}</section>", sidebar.into_inner());
2320 fn sidebar_typedef(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item) {
2321 let mut sidebar = Buffer::new();
2322 sidebar_assoc_items(cx, &mut sidebar, it);
2324 if !sidebar.is_empty() {
2325 write!(buf, "<section>{}</section>", sidebar.into_inner());
2329 fn get_struct_fields_name(fields: &[clean::Item]) -> Vec<String> {
2330 let mut fields = fields
2332 .filter(|f| matches!(*f.kind, clean::StructFieldItem(..)))
2334 f.name.map(|name| format!("<a href=\"#structfield.{name}\">{name}</a>", name = name))
2336 .collect::<Vec<_>>();
2341 fn sidebar_union(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, u: &clean::Union) {
2342 let mut sidebar = Buffer::new();
2343 let fields = get_struct_fields_name(&u.fields);
2345 if !fields.is_empty() {
2346 print_sidebar_block(&mut sidebar, "fields", "Fields", fields.iter());
2349 sidebar_assoc_items(cx, &mut sidebar, it);
2351 if !sidebar.is_empty() {
2352 write!(buf, "<section>{}</section>", sidebar.into_inner());
2356 fn sidebar_enum(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, e: &clean::Enum) {
2357 let mut sidebar = Buffer::new();
2359 let mut variants = e
2364 .map(|name| format!("<a href=\"#variant.{name}\">{name}</a>", name = name))
2366 .collect::<Vec<_>>();
2367 if !variants.is_empty() {
2368 variants.sort_unstable();
2369 print_sidebar_block(&mut sidebar, "variants", "Variants", variants.iter());
2372 sidebar_assoc_items(cx, &mut sidebar, it);
2374 if !sidebar.is_empty() {
2375 write!(buf, "<section>{}</section>", sidebar.into_inner());
2379 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
2399 AssociatedConstants,
2409 const ALL: &'static [Self] = {
2411 // NOTE: The order here affects the order in the UI.
2431 AssociatedConstants,
2441 fn id(self) -> &'static str {
2443 Self::Reexports => "reexports",
2444 Self::Modules => "modules",
2445 Self::Structs => "structs",
2446 Self::Unions => "unions",
2447 Self::Enums => "enums",
2448 Self::Functions => "functions",
2449 Self::TypeDefinitions => "types",
2450 Self::Statics => "statics",
2451 Self::Constants => "constants",
2452 Self::Traits => "traits",
2453 Self::Implementations => "impls",
2454 Self::TypeMethods => "tymethods",
2455 Self::Methods => "methods",
2456 Self::StructFields => "fields",
2457 Self::Variants => "variants",
2458 Self::Macros => "macros",
2459 Self::PrimitiveTypes => "primitives",
2460 Self::AssociatedTypes => "associated-types",
2461 Self::AssociatedConstants => "associated-consts",
2462 Self::ForeignTypes => "foreign-types",
2463 Self::Keywords => "keywords",
2464 Self::OpaqueTypes => "opaque-types",
2465 Self::AttributeMacros => "attributes",
2466 Self::DeriveMacros => "derives",
2467 Self::TraitAliases => "trait-aliases",
2471 fn name(self) -> &'static str {
2473 Self::Reexports => "Re-exports",
2474 Self::Modules => "Modules",
2475 Self::Structs => "Structs",
2476 Self::Unions => "Unions",
2477 Self::Enums => "Enums",
2478 Self::Functions => "Functions",
2479 Self::TypeDefinitions => "Type Definitions",
2480 Self::Statics => "Statics",
2481 Self::Constants => "Constants",
2482 Self::Traits => "Traits",
2483 Self::Implementations => "Implementations",
2484 Self::TypeMethods => "Type Methods",
2485 Self::Methods => "Methods",
2486 Self::StructFields => "Struct Fields",
2487 Self::Variants => "Variants",
2488 Self::Macros => "Macros",
2489 Self::PrimitiveTypes => "Primitive Types",
2490 Self::AssociatedTypes => "Associated Types",
2491 Self::AssociatedConstants => "Associated Constants",
2492 Self::ForeignTypes => "Foreign Types",
2493 Self::Keywords => "Keywords",
2494 Self::OpaqueTypes => "Opaque Types",
2495 Self::AttributeMacros => "Attribute Macros",
2496 Self::DeriveMacros => "Derive Macros",
2497 Self::TraitAliases => "Trait Aliases",
2502 fn item_ty_to_section(ty: ItemType) -> ItemSection {
2504 ItemType::ExternCrate | ItemType::Import => ItemSection::Reexports,
2505 ItemType::Module => ItemSection::Modules,
2506 ItemType::Struct => ItemSection::Structs,
2507 ItemType::Union => ItemSection::Unions,
2508 ItemType::Enum => ItemSection::Enums,
2509 ItemType::Function => ItemSection::Functions,
2510 ItemType::Typedef => ItemSection::TypeDefinitions,
2511 ItemType::Static => ItemSection::Statics,
2512 ItemType::Constant => ItemSection::Constants,
2513 ItemType::Trait => ItemSection::Traits,
2514 ItemType::Impl => ItemSection::Implementations,
2515 ItemType::TyMethod => ItemSection::TypeMethods,
2516 ItemType::Method => ItemSection::Methods,
2517 ItemType::StructField => ItemSection::StructFields,
2518 ItemType::Variant => ItemSection::Variants,
2519 ItemType::Macro => ItemSection::Macros,
2520 ItemType::Primitive => ItemSection::PrimitiveTypes,
2521 ItemType::AssocType => ItemSection::AssociatedTypes,
2522 ItemType::AssocConst => ItemSection::AssociatedConstants,
2523 ItemType::ForeignType => ItemSection::ForeignTypes,
2524 ItemType::Keyword => ItemSection::Keywords,
2525 ItemType::OpaqueTy => ItemSection::OpaqueTypes,
2526 ItemType::ProcAttribute => ItemSection::AttributeMacros,
2527 ItemType::ProcDerive => ItemSection::DeriveMacros,
2528 ItemType::TraitAlias => ItemSection::TraitAliases,
2532 fn sidebar_module(buf: &mut Buffer, items: &[clean::Item]) {
2533 use std::fmt::Write as _;
2535 let mut sidebar = String::new();
2537 let item_sections_in_use: FxHashSet<_> = items
2544 if let clean::ImportItem(ref i) = *it.kind &&
2545 let clean::ImportKind::Simple(s) = i.kind { Some(s) } else { None }
2549 .map(|it| item_ty_to_section(it.type_()))
2551 for &sec in ItemSection::ALL.iter().filter(|sec| item_sections_in_use.contains(sec)) {
2552 let _ = write!(sidebar, "<li><a href=\"#{}\">{}</a></li>", sec.id(), sec.name());
2555 if !sidebar.is_empty() {
2559 <div class=\"block\">\
2568 fn sidebar_foreign_type(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item) {
2569 let mut sidebar = Buffer::new();
2570 sidebar_assoc_items(cx, &mut sidebar, it);
2572 if !sidebar.is_empty() {
2573 write!(buf, "<section>{}</section>", sidebar.into_inner());
2577 pub(crate) const BASIC_KEYWORDS: &str = "rust, rustlang, rust-lang";
2579 /// Returns a list of all paths used in the type.
2580 /// This is used to help deduplicate imported impls
2581 /// for reexported types. If any of the contained
2582 /// types are re-exported, we don't use the corresponding
2583 /// entry from the js file, as inlining will have already
2584 /// picked up the impl
2585 fn collect_paths_for_type(first_ty: clean::Type, cache: &Cache) -> Vec<String> {
2586 let mut out = Vec::new();
2587 let mut visited = FxHashSet::default();
2588 let mut work = VecDeque::new();
2590 let mut process_path = |did: DefId| {
2591 let get_extern = || cache.external_paths.get(&did).map(|s| s.0.clone());
2592 let fqp = cache.exact_paths.get(&did).cloned().or_else(get_extern);
2594 if let Some(path) = fqp {
2595 out.push(join_with_double_colon(&path));
2599 work.push_back(first_ty);
2601 while let Some(ty) = work.pop_front() {
2602 if !visited.insert(ty.clone()) {
2607 clean::Type::Path { path } => process_path(path.def_id()),
2608 clean::Type::Tuple(tys) => {
2609 work.extend(tys.into_iter());
2611 clean::Type::Slice(ty) => {
2612 work.push_back(*ty);
2614 clean::Type::Array(ty, _) => {
2615 work.push_back(*ty);
2617 clean::Type::RawPointer(_, ty) => {
2618 work.push_back(*ty);
2620 clean::Type::BorrowedRef { type_, .. } => {
2621 work.push_back(*type_);
2623 clean::Type::QPath { self_type, trait_, .. } => {
2624 work.push_back(*self_type);
2625 process_path(trait_.def_id());
2633 const MAX_FULL_EXAMPLES: usize = 5;
2634 const NUM_VISIBLE_LINES: usize = 10;
2636 /// Generates the HTML for example call locations generated via the --scrape-examples flag.
2637 fn render_call_locations(w: &mut Buffer, cx: &mut Context<'_>, item: &clean::Item) {
2639 let def_id = item.item_id.expect_def_id();
2640 let key = tcx.def_path_hash(def_id);
2641 let Some(call_locations) = cx.shared.call_locations.get(&key) else { return };
2643 // Generate a unique ID so users can link to this section for a given method
2644 let id = cx.id_map.derive("scraped-examples");
2647 "<div class=\"docblock scraped-example-list\">\
2650 <a href=\"#{id}\">Examples found in repository</a>\
2651 <a class=\"scrape-help\" href=\"{root_path}scrape-examples-help.html\">?</a>\
2653 root_path = cx.root_path(),
2657 // Create a URL to a particular location in a reverse-dependency's source file
2658 let link_to_loc = |call_data: &CallData, loc: &CallLocation| -> (String, String) {
2659 let (line_lo, line_hi) = loc.call_expr.line_span;
2660 let (anchor, title) = if line_lo == line_hi {
2661 ((line_lo + 1).to_string(), format!("line {}", line_lo + 1))
2664 format!("{}-{}", line_lo + 1, line_hi + 1),
2665 format!("lines {}-{}", line_lo + 1, line_hi + 1),
2668 let url = format!("{}{}#{}", cx.root_path(), call_data.url, anchor);
2672 // Generate the HTML for a single example, being the title and code block
2673 let write_example = |w: &mut Buffer, (path, call_data): (&PathBuf, &CallData)| -> bool {
2674 let contents = match fs::read_to_string(&path) {
2675 Ok(contents) => contents,
2677 let span = item.span(tcx).inner();
2679 .span_err(span, &format!("failed to read file {}: {}", path.display(), err));
2684 // To reduce file sizes, we only want to embed the source code needed to understand the example, not
2685 // the entire file. So we find the smallest byte range that covers all items enclosing examples.
2686 assert!(!call_data.locations.is_empty());
2688 call_data.locations.iter().min_by_key(|loc| loc.enclosing_item.byte_span.0).unwrap();
2689 let byte_min = min_loc.enclosing_item.byte_span.0;
2690 let line_min = min_loc.enclosing_item.line_span.0;
2692 call_data.locations.iter().max_by_key(|loc| loc.enclosing_item.byte_span.1).unwrap();
2693 let byte_max = max_loc.enclosing_item.byte_span.1;
2694 let line_max = max_loc.enclosing_item.line_span.1;
2696 // The output code is limited to that byte range.
2697 let contents_subset = &contents[(byte_min as usize)..(byte_max as usize)];
2699 // The call locations need to be updated to reflect that the size of the program has changed.
2700 // Specifically, the ranges are all subtracted by `byte_min` since that's the new zero point.
2701 let (mut byte_ranges, line_ranges): (Vec<_>, Vec<_>) = call_data
2705 let (byte_lo, byte_hi) = loc.call_ident.byte_span;
2706 let (line_lo, line_hi) = loc.call_expr.line_span;
2707 let byte_range = (byte_lo - byte_min, byte_hi - byte_min);
2709 let line_range = (line_lo - line_min, line_hi - line_min);
2710 let (line_url, line_title) = link_to_loc(call_data, loc);
2712 (byte_range, (line_range, line_url, line_title))
2716 let (_, init_url, init_title) = &line_ranges[0];
2717 let needs_expansion = line_max - line_min > NUM_VISIBLE_LINES;
2718 let locations_encoded = serde_json::to_string(&line_ranges).unwrap();
2722 "<div class=\"scraped-example {expanded_cls}\" data-locs=\"{locations}\">\
2723 <div class=\"scraped-example-title\">\
2724 {name} (<a href=\"{url}\">{title}</a>)\
2726 <div class=\"code-wrapper\">",
2727 expanded_cls = if needs_expansion { "" } else { "expanded" },
2728 name = call_data.display_name,
2731 // The locations are encoded as a data attribute, so they can be read
2732 // later by the JS for interactions.
2733 locations = Escape(&locations_encoded)
2736 if line_ranges.len() > 1 {
2737 write!(w, r#"<span class="prev">≺</span> <span class="next">≻</span>"#);
2740 if needs_expansion {
2741 write!(w, r#"<span class="expand">↕</span>"#);
2744 // Look for the example file in the source map if it exists, otherwise return a dummy span
2745 let file_span = (|| {
2746 let source_map = tcx.sess.source_map();
2747 let crate_src = tcx.sess.local_crate_source_file.as_ref()?;
2748 let abs_crate_src = crate_src.canonicalize().ok()?;
2749 let crate_root = abs_crate_src.parent()?.parent()?;
2750 let rel_path = path.strip_prefix(crate_root).ok()?;
2751 let files = source_map.files();
2752 let file = files.iter().find(|file| match &file.name {
2753 FileName::Real(RealFileName::LocalPath(other_path)) => rel_path == other_path,
2756 Some(rustc_span::Span::with_root_ctxt(
2757 file.start_pos + BytePos(byte_min),
2758 file.start_pos + BytePos(byte_max),
2761 .unwrap_or(rustc_span::DUMMY_SP);
2763 // The root path is the inverse of Context::current
2764 let root_path = vec!["../"; cx.current.len() - 1].join("");
2766 let mut decoration_info = FxHashMap::default();
2767 decoration_info.insert("highlight focus", vec![byte_ranges.remove(0)]);
2768 decoration_info.insert("highlight", byte_ranges);
2777 Some(highlight::DecorationInfo(decoration_info)),
2778 sources::SourceContext::Embedded { offset: line_min },
2780 write!(w, "</div></div>");
2785 // The call locations are output in sequence, so that sequence needs to be determined.
2786 // Ideally the most "relevant" examples would be shown first, but there's no general algorithm
2787 // for determining relevance. Instead, we prefer the smallest examples being likely the easiest to
2788 // understand at a glance.
2789 let ordered_locations = {
2790 let sort_criterion = |(_, call_data): &(_, &CallData)| {
2791 // Use the first location because that's what the user will see initially
2792 let (lo, hi) = call_data.locations[0].enclosing_item.byte_span;
2796 let mut locs = call_locations.iter().collect::<Vec<_>>();
2797 locs.sort_by_key(sort_criterion);
2801 let mut it = ordered_locations.into_iter().peekable();
2803 // An example may fail to write if its source can't be read for some reason, so this method
2804 // continues iterating until a write succeeds
2805 let write_and_skip_failure = |w: &mut Buffer, it: &mut Peekable<_>| {
2806 while let Some(example) = it.next() {
2807 if write_example(&mut *w, example) {
2813 // Write just one example that's visible by default in the method's description.
2814 write_and_skip_failure(w, &mut it);
2816 // Then add the remaining examples in a hidden section.
2817 if it.peek().is_some() {
2820 "<details class=\"rustdoc-toggle more-examples-toggle\">\
2821 <summary class=\"hideme\">\
2822 <span>More examples</span>\
2824 <div class=\"hide-more\">Hide additional examples</div>\
2825 <div class=\"more-scraped-examples\">\
2826 <div class=\"toggle-line\"><div class=\"toggle-line-inner\"></div></div>\
2827 <div class=\"more-scraped-examples-inner\">"
2830 // Only generate inline code for MAX_FULL_EXAMPLES number of examples. Otherwise we could
2831 // make the page arbitrarily huge!
2832 for _ in 0..MAX_FULL_EXAMPLES {
2833 write_and_skip_failure(w, &mut it);
2836 // For the remaining examples, generate a <ul> containing links to the source files.
2837 if it.peek().is_some() {
2838 write!(w, r#"<div class="example-links">Additional examples can be found in:<br><ul>"#);
2839 it.for_each(|(_, call_data)| {
2840 let (url, _) = link_to_loc(call_data, &call_data.locations[0]);
2843 r#"<li><a href="{url}">{name}</a></li>"#,
2845 name = call_data.display_name
2848 write!(w, "</ul></div>");
2851 write!(w, "</div></div></details>");
2854 write!(w, "</div>");