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.
37 crate use self::context::*;
38 crate use self::span_map::{collect_spans_and_sources, LinkFromSrc};
40 use std::collections::VecDeque;
41 use std::default::Default;
44 use std::iter::Peekable;
45 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};
53 use rustc_hir::def::CtorKind;
54 use rustc_hir::def_id::DefId;
55 use rustc_hir::Mutability;
56 use rustc_middle::middle::stability;
58 use rustc_middle::ty::TyCtxt;
60 symbol::{kw, sym, Symbol},
61 BytePos, FileName, RealFileName,
63 use serde::ser::SerializeSeq;
64 use serde::{Serialize, Serializer};
66 use crate::clean::{self, ItemId, RenderedLink, SelfTy};
67 use crate::docfs::PathError;
68 use crate::error::Error;
69 use crate::formats::cache::Cache;
70 use crate::formats::item_type::ItemType;
71 use crate::formats::{AssocItemRender, Impl, RenderMode};
72 use crate::html::escape::Escape;
73 use crate::html::format::{
74 href, print_abi_with_space, print_constness_with_space, print_default_space,
75 print_generic_bounds, print_where_clause, Buffer, HrefError, PrintWithSpace,
77 use crate::html::highlight;
78 use crate::html::markdown::{HeadingOffset, Markdown, MarkdownHtml, MarkdownSummaryLine};
79 use crate::html::sources;
80 use crate::scrape_examples::{CallData, CallLocation};
83 /// A pair of name and its optional document.
84 crate type NameDoc = (String, Option<String>);
86 crate fn ensure_trailing_slash(v: &str) -> impl fmt::Display + '_ {
87 crate::html::format::display_fn(move |f| {
88 if !v.ends_with('/') && !v.is_empty() { write!(f, "{}/", v) } else { f.write_str(v) }
92 // Helper structs for rendering items/sidebars and carrying along contextual
95 /// Struct representing one entry in the JS search index. These are all emitted
96 /// by hand to a large JS file at the end of cache-creation.
98 crate struct IndexItem {
103 crate parent: Option<DefId>,
104 crate parent_idx: Option<usize>,
105 crate search_type: Option<IndexItemFunctionType>,
106 crate aliases: Box<[String]>,
109 /// A type used for the search index.
111 crate struct RenderType {
112 name: Option<String>,
113 generics: Option<Vec<TypeWithKind>>,
116 /// Full type of functions/methods in the search index.
118 crate struct IndexItemFunctionType {
119 inputs: Vec<TypeWithKind>,
120 output: Vec<TypeWithKind>,
123 impl Serialize for IndexItemFunctionType {
124 fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
128 // If we couldn't figure out a type, just write `null`.
129 let has_missing = self.inputs.iter().chain(self.output.iter()).any(|i| i.ty.name.is_none());
131 serializer.serialize_none()
133 let mut seq = serializer.serialize_seq(None)?;
134 seq.serialize_element(&self.inputs)?;
135 match self.output.as_slice() {
137 [one] => seq.serialize_element(one)?,
138 all => seq.serialize_element(all)?,
146 crate struct TypeWithKind {
151 impl From<(RenderType, ItemType)> for TypeWithKind {
152 fn from(x: (RenderType, ItemType)) -> TypeWithKind {
153 TypeWithKind { ty: x.0, kind: x.1 }
157 impl Serialize for TypeWithKind {
158 fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
162 let mut seq = serializer.serialize_seq(None)?;
163 seq.serialize_element(&self.ty.name)?;
164 seq.serialize_element(&self.kind)?;
165 if let Some(generics) = &self.ty.generics {
166 seq.serialize_element(generics)?;
172 #[derive(Debug, Clone)]
173 crate struct StylePath {
174 /// The path to the theme
176 /// What the `disabled` attribute should be set to in the HTML tag
177 crate disabled: bool,
180 fn write_srclink(cx: &Context<'_>, item: &clean::Item, buf: &mut Buffer) {
181 if let Some(l) = cx.src_href(item) {
182 write!(buf, "<a class=\"srclink\" href=\"{}\" title=\"goto source code\">[src]</a>", l)
186 #[derive(Debug, Eq, PartialEq, Hash)]
193 fn new(mut url: String, name: String) -> ItemEntry {
194 while url.starts_with('/') {
197 ItemEntry { url, name }
202 crate fn print(&self) -> impl fmt::Display + '_ {
203 crate::html::format::display_fn(move |f| {
204 write!(f, "<a href=\"{}\">{}</a>", self.url, Escape(&self.name))
209 impl PartialOrd for ItemEntry {
210 fn partial_cmp(&self, other: &ItemEntry) -> Option<::std::cmp::Ordering> {
211 Some(self.cmp(other))
215 impl Ord for ItemEntry {
216 fn cmp(&self, other: &ItemEntry) -> ::std::cmp::Ordering {
217 self.name.cmp(&other.name)
223 structs: FxHashSet<ItemEntry>,
224 enums: FxHashSet<ItemEntry>,
225 unions: FxHashSet<ItemEntry>,
226 primitives: FxHashSet<ItemEntry>,
227 traits: FxHashSet<ItemEntry>,
228 macros: FxHashSet<ItemEntry>,
229 functions: FxHashSet<ItemEntry>,
230 typedefs: FxHashSet<ItemEntry>,
231 opaque_tys: FxHashSet<ItemEntry>,
232 statics: FxHashSet<ItemEntry>,
233 constants: FxHashSet<ItemEntry>,
234 attributes: FxHashSet<ItemEntry>,
235 derives: FxHashSet<ItemEntry>,
236 trait_aliases: FxHashSet<ItemEntry>,
240 fn new() -> AllTypes {
241 let new_set = |cap| FxHashSet::with_capacity_and_hasher(cap, Default::default());
243 structs: new_set(100),
245 unions: new_set(100),
246 primitives: new_set(26),
247 traits: new_set(100),
248 macros: new_set(100),
249 functions: new_set(100),
250 typedefs: new_set(100),
251 opaque_tys: new_set(100),
252 statics: new_set(100),
253 constants: new_set(100),
254 attributes: new_set(100),
255 derives: new_set(100),
256 trait_aliases: new_set(100),
260 fn append(&mut self, item_name: String, item_type: &ItemType) {
261 let mut url: Vec<_> = item_name.split("::").skip(1).collect();
262 if let Some(name) = url.pop() {
263 let new_url = format!("{}/{}.{}.html", url.join("/"), item_type, name);
265 let name = url.join("::");
267 ItemType::Struct => self.structs.insert(ItemEntry::new(new_url, name)),
268 ItemType::Enum => self.enums.insert(ItemEntry::new(new_url, name)),
269 ItemType::Union => self.unions.insert(ItemEntry::new(new_url, name)),
270 ItemType::Primitive => self.primitives.insert(ItemEntry::new(new_url, name)),
271 ItemType::Trait => self.traits.insert(ItemEntry::new(new_url, name)),
272 ItemType::Macro => self.macros.insert(ItemEntry::new(new_url, name)),
273 ItemType::Function => self.functions.insert(ItemEntry::new(new_url, name)),
274 ItemType::Typedef => self.typedefs.insert(ItemEntry::new(new_url, name)),
275 ItemType::OpaqueTy => self.opaque_tys.insert(ItemEntry::new(new_url, name)),
276 ItemType::Static => self.statics.insert(ItemEntry::new(new_url, name)),
277 ItemType::Constant => self.constants.insert(ItemEntry::new(new_url, name)),
278 ItemType::ProcAttribute => self.attributes.insert(ItemEntry::new(new_url, name)),
279 ItemType::ProcDerive => self.derives.insert(ItemEntry::new(new_url, name)),
280 ItemType::TraitAlias => self.trait_aliases.insert(ItemEntry::new(new_url, name)),
288 fn print(self, f: &mut Buffer) {
289 fn print_entries(f: &mut Buffer, e: &FxHashSet<ItemEntry>, title: &str, class: &str) {
291 let mut e: Vec<&ItemEntry> = e.iter().collect();
295 "<h3 id=\"{}\">{}</h3><ul class=\"{} docblock\">",
296 title.replace(' ', "-"), // IDs cannot contain whitespaces.
302 write!(f, "<li>{}</li>", s.print());
305 f.write_str("</ul>");
311 <span class=\"in-band\">List of all items</span>\
312 <span class=\"out-of-band\">\
313 <span id=\"render-detail\">\
314 <a id=\"toggle-all-docs\" href=\"javascript:void(0)\" \
315 title=\"collapse all docs\">\
316 [<span class=\"inner\">−</span>]\
322 // Note: print_entries does not escape the title, because we know the current set of titles
323 // doesn't require escaping.
324 print_entries(f, &self.structs, "Structs", "structs");
325 print_entries(f, &self.enums, "Enums", "enums");
326 print_entries(f, &self.unions, "Unions", "unions");
327 print_entries(f, &self.primitives, "Primitives", "primitives");
328 print_entries(f, &self.traits, "Traits", "traits");
329 print_entries(f, &self.macros, "Macros", "macros");
330 print_entries(f, &self.attributes, "Attribute Macros", "attributes");
331 print_entries(f, &self.derives, "Derive Macros", "derives");
332 print_entries(f, &self.functions, "Functions", "functions");
333 print_entries(f, &self.typedefs, "Typedefs", "typedefs");
334 print_entries(f, &self.trait_aliases, "Trait Aliases", "trait-aliases");
335 print_entries(f, &self.opaque_tys, "Opaque Types", "opaque-types");
336 print_entries(f, &self.statics, "Statics", "statics");
337 print_entries(f, &self.constants, "Constants", "constants")
344 description: &'static str,
345 sub_settings: Vec<Setting>,
348 js_data_name: &'static str,
349 description: &'static str,
353 js_data_name: &'static str,
354 description: &'static str,
355 default_value: &'static str,
356 options: Vec<(String, String)>,
361 fn display(&self, root_path: &str, suffix: &str) -> String {
363 Setting::Section { description, ref sub_settings } => format!(
364 "<div class=\"setting-line\">\
365 <div class=\"title\">{}</div>\
366 <div class=\"sub-settings\">{}</div>
369 sub_settings.iter().map(|s| s.display(root_path, suffix)).collect::<String>()
371 Setting::Toggle { js_data_name, description, default_value } => format!(
372 "<div class=\"setting-line\">\
373 <label class=\"toggle\">\
374 <input type=\"checkbox\" id=\"{}\" {}>\
375 <span class=\"slider\"></span>\
380 if default_value { " checked" } else { "" },
383 Setting::Select { js_data_name, description, default_value, ref options } => format!(
384 "<div class=\"setting-line\">\
386 <label class=\"select-wrapper\">\
387 <select id=\"{}\" autocomplete=\"off\">{}</select>\
388 <img src=\"{}down-arrow{}.svg\" alt=\"Select item\">\
396 "<option value=\"{}\" {}>{}</option>",
398 if opt.0 == default_value { "selected" } else { "" },
401 .collect::<String>(),
409 impl From<(&'static str, &'static str, bool)> for Setting {
410 fn from(values: (&'static str, &'static str, bool)) -> Setting {
411 Setting::Toggle { js_data_name: values.0, description: values.1, default_value: values.2 }
415 impl<T: Into<Setting>> From<(&'static str, Vec<T>)> for Setting {
416 fn from(values: (&'static str, Vec<T>)) -> Setting {
418 description: values.0,
419 sub_settings: values.1.into_iter().map(|v| v.into()).collect::<Vec<_>>(),
424 fn settings(root_path: &str, suffix: &str, themes: &[StylePath]) -> Result<String, Error> {
425 let theme_names: Vec<(String, String)> = themes
429 try_none!(try_none!(entry.path.file_stem(), &entry.path).to_str(), &entry.path)
432 Ok((theme.clone(), theme))
434 .collect::<Result<_, Error>>()?;
436 // (id, explanation, default value)
437 let settings: &[Setting] = &[
441 Setting::from(("use-system-theme", "Use system theme", true)),
443 js_data_name: "preferred-dark-theme",
444 description: "Preferred dark theme",
445 default_value: "dark",
446 options: theme_names.clone(),
449 js_data_name: "preferred-light-theme",
450 description: "Preferred light theme",
451 default_value: "light",
452 options: theme_names,
457 ("auto-hide-large-items", "Auto-hide item contents for large items.", true).into(),
458 ("auto-hide-method-docs", "Auto-hide item methods' documentation", false).into(),
459 ("auto-hide-trait-implementations", "Auto-hide trait implementation documentation", false)
461 ("go-to-only-result", "Directly go to item in search if there is only one result", false)
463 ("line-numbers", "Show line numbers on code examples", false).into(),
464 ("disable-shortcuts", "Disable keyboard shortcuts", false).into(),
469 <span class=\"in-band\">Rustdoc settings</span>\
471 <div class=\"settings\">{}</div>\
472 <script src=\"{}settings{}.js\"></script>",
473 settings.iter().map(|s| s.display(root_path, suffix)).collect::<String>(),
483 parent: Option<&clean::Item>,
484 heading_offset: HeadingOffset,
486 if let Some(ref name) = item.name {
487 info!("Documenting {}", name);
489 document_item_info(w, cx, item, parent);
490 if parent.is_none() {
491 document_full_collapsible(w, item, cx, heading_offset);
493 document_full(w, item, cx, heading_offset);
497 /// Render md_text as markdown.
502 links: Vec<RenderedLink>,
503 heading_offset: HeadingOffset,
505 let mut ids = cx.id_map.borrow_mut();
508 "<div class=\"docblock\">{}</div>",
513 error_codes: cx.shared.codes,
514 edition: cx.shared.edition(),
515 playground: &cx.shared.playground,
522 /// Writes a documentation block containing only the first paragraph of the documentation. If the
523 /// docs are longer, a "Read more" link is appended to the end.
528 link: AssocItemLink<'_>,
529 parent: &clean::Item,
532 document_item_info(w, cx, item, Some(parent));
536 if let Some(s) = item.doc_value() {
537 let mut summary_html = MarkdownSummaryLine(&s, &item.links(cx)).into_string();
539 if s.contains('\n') {
540 let link = format!(r#" <a href="{}">Read more</a>"#, naive_assoc_href(item, link, cx));
542 if let Some(idx) = summary_html.rfind("</p>") {
543 summary_html.insert_str(idx, &link);
545 summary_html.push_str(&link);
549 write!(w, "<div class='docblock'>{}</div>", summary_html,);
553 fn document_full_collapsible(
557 heading_offset: HeadingOffset,
559 document_full_inner(w, item, cx, true, heading_offset);
566 heading_offset: HeadingOffset,
568 document_full_inner(w, item, cx, false, heading_offset);
571 fn document_full_inner(
575 is_collapsible: bool,
576 heading_offset: HeadingOffset,
578 if let Some(s) = cx.shared.maybe_collapsed_doc_value(item) {
579 debug!("Doc block: =====\n{}\n=====", s);
582 "<details class=\"rustdoc-toggle top-doc\" open>\
583 <summary class=\"hideme\">\
584 <span>Expand description</span>\
587 render_markdown(w, cx, &s, item.links(cx), heading_offset);
588 w.write_str("</details>");
590 render_markdown(w, cx, &s, item.links(cx), heading_offset);
594 let kind = match &*item.kind {
595 clean::ItemKind::StrippedItem(box kind) | kind => kind,
598 if let clean::ItemKind::FunctionItem(..) | clean::ItemKind::MethodItem(..) = kind {
599 render_call_locations(w, cx, item);
603 /// Add extra information about an item such as:
607 /// * Required features (through the `doc_cfg` feature)
608 fn document_item_info(
612 parent: Option<&clean::Item>,
614 let item_infos = short_item_info(item, cx, parent);
615 if !item_infos.is_empty() {
616 w.write_str("<div class=\"item-info\">");
617 for info in item_infos {
620 w.write_str("</div>");
624 fn portability(item: &clean::Item, parent: Option<&clean::Item>) -> Option<String> {
625 let cfg = match (&item.cfg, parent.and_then(|p| p.cfg.as_ref())) {
626 (Some(cfg), Some(parent_cfg)) => cfg.simplify_with(parent_cfg),
627 (cfg, _) => cfg.as_deref().cloned(),
630 debug!("Portability {:?} - {:?} = {:?}", item.cfg, parent.and_then(|p| p.cfg.as_ref()), cfg);
632 Some(format!("<div class=\"stab portability\">{}</div>", cfg?.render_long_html()))
635 /// Render the stability, deprecation and portability information that is displayed at the top of
636 /// the item's documentation.
640 parent: Option<&clean::Item>,
642 let mut extra_info = vec![];
643 let error_codes = cx.shared.codes;
645 if let Some(depr @ Deprecation { note, since, is_since_rustc_version: _, suggestion: _ }) =
646 item.deprecation(cx.tcx())
648 // We display deprecation messages for #[deprecated] and #[rustc_deprecated]
649 // but only display the future-deprecation messages for #[rustc_deprecated].
650 let mut message = if let Some(since) = since {
651 let since = &since.as_str();
652 if !stability::deprecation_in_effect(&depr) {
654 String::from("Deprecating in a future Rust version")
656 format!("Deprecating in {}", Escape(since))
659 format!("Deprecated since {}", Escape(since))
662 String::from("Deprecated")
665 if let Some(note) = note {
666 let note = note.as_str();
667 let mut ids = cx.id_map.borrow_mut();
668 let html = MarkdownHtml(
673 &cx.shared.playground,
675 message.push_str(&format!(": {}", html.into_string()));
677 extra_info.push(format!(
678 "<div class=\"stab deprecated\"><span class=\"emoji\">👎</span> {}</div>",
683 // Render unstable items. But don't render "rustc_private" crates (internal compiler crates).
684 // Those crates are permanently unstable so it makes no sense to render "unstable" everywhere.
685 if let Some((StabilityLevel::Unstable { reason, issue, .. }, feature)) = item
688 .filter(|stab| stab.feature != sym::rustc_private)
689 .map(|stab| (stab.level, stab.feature))
692 "<span class=\"emoji\">🔬</span> This is a nightly-only experimental API.".to_owned();
694 let mut feature = format!("<code>{}</code>", Escape(&feature.as_str()));
695 if let (Some(url), Some(issue)) = (&cx.shared.issue_tracker_base_url, issue) {
696 feature.push_str(&format!(
697 " <a href=\"{url}{issue}\">#{issue}</a>",
703 message.push_str(&format!(" ({})", feature));
705 if let Some(unstable_reason) = reason {
706 let mut ids = cx.id_map.borrow_mut();
708 "<details><summary>{}</summary>{}</details>",
711 &unstable_reason.as_str(),
715 &cx.shared.playground,
721 extra_info.push(format!("<div class=\"stab unstable\">{}</div>", message));
724 if let Some(portability) = portability(item, parent) {
725 extra_info.push(portability);
731 // Render the list of items inside one of the sections "Trait Implementations",
732 // "Auto Trait Implementations," "Blanket Trait Implementations" (on struct/enum pages).
733 fn render_impls(cx: &Context<'_>, w: &mut Buffer, impls: &[&&Impl], containing_item: &clean::Item) {
735 let mut rendered_impls = impls
738 let did = i.trait_did().unwrap();
739 let provided_trait_methods = i.inner_impl().provided_trait_methods(tcx);
740 let assoc_link = AssocItemLink::GotoSource(did.into(), &provided_trait_methods);
741 let mut buffer = if w.is_for_html() { Buffer::html() } else { Buffer::new() };
751 ImplRenderingParameters {
753 is_on_foreign_type: false,
754 show_default_items: true,
755 show_non_assoc_items: true,
756 toggle_open_by_default: true,
761 .collect::<Vec<_>>();
762 rendered_impls.sort();
763 w.write_str(&rendered_impls.join(""));
766 fn naive_assoc_href(it: &clean::Item, link: AssocItemLink<'_>, cx: &Context<'_>) -> String {
767 use crate::formats::item_type::ItemType::*;
769 let name = it.name.as_ref().unwrap();
770 let ty = match it.type_() {
771 Typedef | AssocType => AssocType,
775 let anchor = format!("#{}.{}", ty, name);
777 AssocItemLink::Anchor(Some(ref id)) => format!("#{}", id),
778 AssocItemLink::Anchor(None) => anchor,
779 AssocItemLink::GotoSource(did, _) => {
780 href(did.expect_def_id(), cx).map(|p| format!("{}{}", p.0, anchor)).unwrap_or(anchor)
789 _default: Option<&String>,
790 link: AssocItemLink<'_>,
796 "{}{}const <a href=\"{}\" class=\"constant\">{}</a>: {}",
798 it.visibility.print_with_space(it.def_id, cx),
799 naive_assoc_href(it, link, cx),
800 it.name.as_ref().unwrap(),
808 bounds: &[clean::GenericBound],
809 default: Option<&clean::Type>,
810 link: AssocItemLink<'_>,
816 "{}type <a href=\"{}\" class=\"type\">{}</a>",
818 naive_assoc_href(it, link, cx),
819 it.name.as_ref().unwrap()
821 if !bounds.is_empty() {
822 write!(w, ": {}", print_generic_bounds(bounds, cx))
824 if let Some(default) = default {
825 write!(w, " = {}", default.print(cx))
829 fn render_stability_since_raw(
832 const_stability: Option<&ConstStability>,
833 containing_ver: Option<&str>,
834 containing_const_ver: Option<&str>,
836 let ver = ver.filter(|inner| !inner.is_empty());
838 match (ver, const_stability) {
839 // stable and const stable
840 (Some(v), Some(ConstStability { level: StabilityLevel::Stable { since }, .. }))
841 if Some(since.as_str()).as_deref() != containing_const_ver =>
845 "<span class=\"since\" title=\"Stable since Rust version {0}, const since {1}\">{0} (const: {1})</span>",
849 // stable and const unstable
852 Some(ConstStability { level: StabilityLevel::Unstable { issue, .. }, feature, .. }),
856 "<span class=\"since\" title=\"Stable since Rust version {0}, const unstable\">{0} (const: ",
859 if let Some(n) = issue {
862 "<a href=\"https://github.com/rust-lang/rust/issues/{}\" title=\"Tracking issue for {}\">unstable</a>",
866 write!(w, "unstable");
868 write!(w, ")</span>");
871 (Some(v), _) if ver != containing_ver => {
874 "<span class=\"since\" title=\"Stable since Rust version {0}\">{0}</span>",
882 fn render_assoc_item(
885 link: AssocItemLink<'_>,
892 header: hir::FnHeader,
895 link: AssocItemLink<'_>,
899 let name = meth.name.as_ref().unwrap();
900 let href = match link {
901 AssocItemLink::Anchor(Some(ref id)) => Some(format!("#{}", id)),
902 AssocItemLink::Anchor(None) => Some(format!("#{}.{}", meth.type_(), name)),
903 AssocItemLink::GotoSource(did, provided_methods) => {
904 // We're creating a link from an impl-item to the corresponding
905 // trait-item and need to map the anchored type accordingly.
906 let ty = if provided_methods.contains(name) {
912 match (href(did.expect_def_id(), cx), ty) {
913 (Ok(p), ty) => Some(format!("{}#{}.{}", p.0, ty, name)),
914 (Err(HrefError::DocumentationNotBuilt), ItemType::TyMethod) => None,
915 (Err(_), ty) => Some(format!("#{}.{}", ty, name)),
919 let vis = meth.visibility.print_with_space(meth.def_id, cx).to_string();
921 print_constness_with_space(&header.constness, meth.const_stability(cx.tcx()));
922 let asyncness = header.asyncness.print_with_space();
923 let unsafety = header.unsafety.print_with_space();
924 let defaultness = print_default_space(meth.is_default());
925 let abi = print_abi_with_space(header.abi).to_string();
927 // NOTE: `{:#}` does not print HTML formatting, `{}` does. So `g.print` can't be reused between the length calculation and `write!`.
928 let generics_len = format!("{:#}", g.print(cx)).len();
929 let mut header_len = "fn ".len()
936 + name.as_str().len()
939 let (indent, indent_str, end_newline) = if parent == ItemType::Trait {
941 let indent_str = " ";
942 render_attributes_in_pre(w, meth, indent_str);
943 (4, indent_str, false)
945 render_attributes_in_code(w, meth);
948 w.reserve(header_len + "<a href=\"\" class=\"fnname\">{".len() + "</a>".len());
951 "{indent}{vis}{constness}{asyncness}{unsafety}{defaultness}{abi}fn <a {href} class=\"fnname\">{name}</a>\
952 {generics}{decl}{notable_traits}{where_clause}",
955 constness = constness,
956 asyncness = asyncness,
958 defaultness = defaultness,
960 // links without a href are valid - https://www.w3schools.com/tags/att_a_href.asp
961 href = href.map(|href| format!("href=\"{}\"", href)).unwrap_or_else(|| "".to_string()),
963 generics = g.print(cx),
964 decl = d.full_print(header_len, indent, header.asyncness, cx),
965 notable_traits = notable_traits_decl(d, cx),
966 where_clause = print_where_clause(g, cx, indent, end_newline),
970 clean::StrippedItem(..) => {}
971 clean::TyMethodItem(ref m) => {
972 method(w, item, m.header, &m.generics, &m.decl, link, parent, cx)
974 clean::MethodItem(ref m, _) => {
975 method(w, item, m.header, &m.generics, &m.decl, link, parent, cx)
977 clean::AssocConstItem(ref ty, ref default) => assoc_const(
983 if parent == ItemType::Trait { " " } else { "" },
986 clean::AssocTypeItem(ref bounds, ref default) => assoc_type(
992 if parent == ItemType::Trait { " " } else { "" },
995 _ => panic!("render_assoc_item called on non-associated-item"),
999 const ALLOWED_ATTRIBUTES: &[Symbol] =
1000 &[sym::export_name, sym::link_section, sym::no_mangle, sym::repr, sym::non_exhaustive];
1002 fn attributes(it: &clean::Item) -> Vec<String> {
1006 .filter_map(|attr| {
1007 if ALLOWED_ATTRIBUTES.contains(&attr.name_or_empty()) {
1008 Some(pprust::attribute_to_string(attr).replace("\n", "").replace(" ", " "))
1016 // When an attribute is rendered inside a `<pre>` tag, it is formatted using
1017 // a whitespace prefix and newline.
1018 fn render_attributes_in_pre(w: &mut Buffer, it: &clean::Item, prefix: &str) {
1019 for a in attributes(it) {
1020 writeln!(w, "{}{}", prefix, a);
1024 // When an attribute is rendered inside a <code> tag, it is formatted using
1025 // a div to produce a newline after it.
1026 fn render_attributes_in_code(w: &mut Buffer, it: &clean::Item) {
1027 for a in attributes(it) {
1028 write!(w, "<div class=\"code-attribute\">{}</div>", a);
1032 #[derive(Copy, Clone)]
1033 enum AssocItemLink<'a> {
1034 Anchor(Option<&'a str>),
1035 GotoSource(ItemId, &'a FxHashSet<Symbol>),
1038 impl<'a> AssocItemLink<'a> {
1039 fn anchor(&self, id: &'a str) -> Self {
1041 AssocItemLink::Anchor(_) => AssocItemLink::Anchor(Some(id)),
1042 ref other => *other,
1047 fn render_assoc_items(
1050 containing_item: &clean::Item,
1052 what: AssocItemRender<'_>,
1054 let mut derefs = FxHashSet::default();
1056 render_assoc_items_inner(w, cx, containing_item, it, what, &mut derefs)
1059 fn render_assoc_items_inner(
1062 containing_item: &clean::Item,
1064 what: AssocItemRender<'_>,
1065 derefs: &mut FxHashSet<DefId>,
1067 info!("Documenting associated items of {:?}", containing_item.name);
1068 let cache = cx.cache();
1069 let v = match cache.impls.get(&it) {
1073 let (non_trait, traits): (Vec<_>, _) = v.iter().partition(|i| i.inner_impl().trait_.is_none());
1074 if !non_trait.is_empty() {
1075 let mut tmp_buf = Buffer::empty_from(w);
1076 let render_mode = match what {
1077 AssocItemRender::All => {
1079 "<h2 id=\"implementations\" class=\"small-section-header\">\
1080 Implementations<a href=\"#implementations\" class=\"anchor\"></a>\
1085 AssocItemRender::DerefFor { trait_, type_, deref_mut_ } => {
1087 cx.derive_id(small_url_encode(format!("deref-methods-{:#}", type_.print(cx))));
1088 if let Some(def_id) = type_.def_id(cx.cache()) {
1089 cx.deref_id_map.borrow_mut().insert(def_id, id.clone());
1093 "<h2 id=\"{id}\" class=\"small-section-header\">\
1094 <span>Methods from {trait_}<Target = {type_}></span>\
1095 <a href=\"#{id}\" class=\"anchor\"></a>\
1098 trait_ = trait_.print(cx),
1099 type_ = type_.print(cx),
1101 RenderMode::ForDeref { mut_: deref_mut_ }
1104 let mut impls_buf = Buffer::empty_from(w);
1105 for i in &non_trait {
1111 AssocItemLink::Anchor(None),
1115 ImplRenderingParameters {
1116 show_def_docs: true,
1117 is_on_foreign_type: false,
1118 show_default_items: true,
1119 show_non_assoc_items: true,
1120 toggle_open_by_default: true,
1124 if !impls_buf.is_empty() {
1125 w.push_buffer(tmp_buf);
1126 w.push_buffer(impls_buf);
1130 if !traits.is_empty() {
1132 traits.iter().find(|t| t.trait_did() == cx.tcx().lang_items().deref_trait());
1133 if let Some(impl_) = deref_impl {
1135 traits.iter().any(|t| t.trait_did() == cx.tcx().lang_items().deref_mut_trait());
1136 render_deref_methods(w, cx, impl_, containing_item, has_deref_mut, derefs);
1139 // If we were already one level into rendering deref methods, we don't want to render
1140 // anything after recursing into any further deref methods above.
1141 if let AssocItemRender::DerefFor { .. } = what {
1145 let (synthetic, concrete): (Vec<&&Impl>, Vec<&&Impl>) =
1146 traits.iter().partition(|t| t.inner_impl().kind.is_auto());
1147 let (blanket_impl, concrete): (Vec<&&Impl>, _) =
1148 concrete.into_iter().partition(|t| t.inner_impl().kind.is_blanket());
1150 let mut impls = Buffer::empty_from(w);
1151 render_impls(cx, &mut impls, &concrete, containing_item);
1152 let impls = impls.into_inner();
1153 if !impls.is_empty() {
1156 "<h2 id=\"trait-implementations\" class=\"small-section-header\">\
1157 Trait Implementations<a href=\"#trait-implementations\" class=\"anchor\"></a>\
1159 <div id=\"trait-implementations-list\">{}</div>",
1164 if !synthetic.is_empty() {
1166 "<h2 id=\"synthetic-implementations\" class=\"small-section-header\">\
1167 Auto Trait Implementations\
1168 <a href=\"#synthetic-implementations\" class=\"anchor\"></a>\
1170 <div id=\"synthetic-implementations-list\">",
1172 render_impls(cx, w, &synthetic, containing_item);
1173 w.write_str("</div>");
1176 if !blanket_impl.is_empty() {
1178 "<h2 id=\"blanket-implementations\" class=\"small-section-header\">\
1179 Blanket Implementations\
1180 <a href=\"#blanket-implementations\" class=\"anchor\"></a>\
1182 <div id=\"blanket-implementations-list\">",
1184 render_impls(cx, w, &blanket_impl, containing_item);
1185 w.write_str("</div>");
1190 fn render_deref_methods(
1194 container_item: &clean::Item,
1196 derefs: &mut FxHashSet<DefId>,
1198 let cache = cx.cache();
1199 let deref_type = impl_.inner_impl().trait_.as_ref().unwrap();
1200 let (target, real_target) = impl_
1204 .find_map(|item| match *item.kind {
1205 clean::TypedefItem(ref t, true) => Some(match *t {
1206 clean::Typedef { item_type: Some(ref type_), .. } => (type_, &t.type_),
1207 _ => (&t.type_, &t.type_),
1211 .expect("Expected associated type binding");
1212 debug!("Render deref methods for {:#?}, target {:#?}", impl_.inner_impl().for_, target);
1214 AssocItemRender::DerefFor { trait_: deref_type, type_: real_target, deref_mut_: deref_mut };
1215 if let Some(did) = target.def_id(cache) {
1216 if let Some(type_did) = impl_.inner_impl().for_.def_id(cache) {
1217 // `impl Deref<Target = S> for S`
1218 if did == type_did || !derefs.insert(did) {
1219 // Avoid infinite cycles
1223 render_assoc_items_inner(w, cx, container_item, did, what, derefs);
1225 if let Some(prim) = target.primitive_type() {
1226 if let Some(&did) = cache.primitive_locations.get(&prim) {
1227 render_assoc_items_inner(w, cx, container_item, did, what, derefs);
1233 fn should_render_item(item: &clean::Item, deref_mut_: bool, tcx: TyCtxt<'_>) -> bool {
1234 let self_type_opt = match *item.kind {
1235 clean::MethodItem(ref method, _) => method.decl.self_type(),
1236 clean::TyMethodItem(ref method) => method.decl.self_type(),
1240 if let Some(self_ty) = self_type_opt {
1241 let (by_mut_ref, by_box, by_value) = match self_ty {
1242 SelfTy::SelfBorrowed(_, mutability)
1243 | SelfTy::SelfExplicit(clean::BorrowedRef { mutability, .. }) => {
1244 (mutability == Mutability::Mut, false, false)
1246 SelfTy::SelfExplicit(clean::ResolvedPath { did, .. }) => {
1247 (false, Some(did) == tcx.lang_items().owned_box(), false)
1249 SelfTy::SelfValue => (false, false, true),
1250 _ => (false, false, false),
1253 (deref_mut_ || !by_mut_ref) && !by_box && !by_value
1259 fn notable_traits_decl(decl: &clean::FnDecl, cx: &Context<'_>) -> String {
1260 let mut out = Buffer::html();
1262 if let Some(did) = decl.output.as_return().and_then(|t| t.def_id(cx.cache())) {
1263 if let Some(impls) = cx.cache().impls.get(&did) {
1265 let impl_ = i.inner_impl();
1266 if let Some(trait_) = &impl_.trait_ {
1267 let trait_did = trait_.def_id();
1269 if cx.cache().traits.get(&trait_did).map_or(false, |t| t.is_notable) {
1273 "<div class=\"notable\">Notable traits for {}</div>\
1274 <code class=\"content\">",
1275 impl_.for_.print(cx)
1279 //use the "where" class here to make it small
1282 "<span class=\"where fmt-newline\">{}</span>",
1283 impl_.print(false, cx)
1285 for it in &impl_.items {
1286 if let clean::TypedefItem(ref tydef, _) = *it.kind {
1287 out.push_str("<span class=\"where fmt-newline\"> ");
1288 let empty_set = FxHashSet::default();
1290 AssocItemLink::GotoSource(trait_did.into(), &empty_set);
1291 assoc_type(&mut out, it, &[], Some(&tydef.type_), src_link, "", cx);
1292 out.push_str(";</span>");
1301 if !out.is_empty() {
1304 "<span class=\"notable-traits\"><span class=\"notable-traits-tooltip\">ⓘ\
1305 <div class=\"notable-traits-tooltiptext\"><span class=\"docblock\">",
1307 out.push_str("</code></span></div></span></span>");
1313 #[derive(Clone, Copy, Debug)]
1314 struct ImplRenderingParameters {
1315 show_def_docs: bool,
1316 is_on_foreign_type: bool,
1317 show_default_items: bool,
1318 /// Whether or not to show methods.
1319 show_non_assoc_items: bool,
1320 toggle_open_by_default: bool,
1327 parent: &clean::Item,
1328 link: AssocItemLink<'_>,
1329 render_mode: RenderMode,
1330 use_absolute: Option<bool>,
1332 rendering_params: ImplRenderingParameters,
1334 let cache = cx.cache();
1335 let traits = &cache.traits;
1336 let trait_ = i.trait_did().map(|did| &traits[&did]);
1337 let mut close_tags = String::new();
1339 // For trait implementations, the `interesting` output contains all methods that have doc
1340 // comments, and the `boring` output contains all methods that do not. The distinction is
1341 // used to allow hiding the boring methods.
1342 // `containing_item` is used for rendering stability info. If the parent is a trait impl,
1343 // `containing_item` will the grandparent, since trait impls can't have stability attached.
1345 boring: &mut Buffer,
1346 interesting: &mut Buffer,
1349 parent: &clean::Item,
1350 containing_item: &clean::Item,
1351 link: AssocItemLink<'_>,
1352 render_mode: RenderMode,
1353 is_default_item: bool,
1354 trait_: Option<&clean::Trait>,
1355 rendering_params: ImplRenderingParameters,
1357 let item_type = item.type_();
1358 let name = item.name.as_ref().unwrap();
1360 let render_method_item = rendering_params.show_non_assoc_items
1361 && match render_mode {
1362 RenderMode::Normal => true,
1363 RenderMode::ForDeref { mut_: deref_mut_ } => {
1364 should_render_item(item, deref_mut_, cx.tcx())
1368 let in_trait_class = if trait_.is_some() { " trait-impl" } else { "" };
1370 let mut doc_buffer = Buffer::empty_from(boring);
1371 let mut info_buffer = Buffer::empty_from(boring);
1372 let mut short_documented = true;
1374 if render_method_item {
1375 if !is_default_item {
1376 if let Some(t) = trait_ {
1377 // The trait item may have been stripped so we might not
1378 // find any documentation or stability for it.
1379 if let Some(it) = t.items.iter().find(|i| i.name == item.name) {
1380 // We need the stability of the item from the trait
1381 // because impls can't have a stability.
1382 if item.doc_value().is_some() {
1383 document_item_info(&mut info_buffer, cx, it, Some(parent));
1384 document_full(&mut doc_buffer, item, cx, HeadingOffset::H5);
1385 short_documented = false;
1387 // In case the item isn't documented,
1388 // provide short documentation from the trait.
1395 rendering_params.show_def_docs,
1400 document_item_info(&mut info_buffer, cx, item, Some(parent));
1401 if rendering_params.show_def_docs {
1402 document_full(&mut doc_buffer, item, cx, HeadingOffset::H5);
1403 short_documented = false;
1413 rendering_params.show_def_docs,
1417 let w = if short_documented && trait_.is_some() { interesting } else { boring };
1419 let toggled = !doc_buffer.is_empty();
1421 let method_toggle_class =
1422 if item_type == ItemType::Method { " method-toggle" } else { "" };
1423 write!(w, "<details class=\"rustdoc-toggle{}\" open><summary>", method_toggle_class);
1426 clean::MethodItem(..) | clean::TyMethodItem(_) => {
1427 // Only render when the method is not static or we allow static methods
1428 if render_method_item {
1429 let id = cx.derive_id(format!("{}.{}", item_type, name));
1430 let source_id = trait_
1431 .and_then(|trait_| {
1432 trait_.items.iter().find(|item| {
1433 item.name.map(|n| n.as_str().eq(&name.as_str())).unwrap_or(false)
1436 .map(|item| format!("{}.{}", item.type_(), name));
1439 "<div id=\"{}\" class=\"{}{} has-srclink\">",
1440 id, item_type, in_trait_class,
1442 render_rightside(w, cx, item, containing_item);
1443 write!(w, "<a href=\"#{}\" class=\"anchor\"></a>", id);
1444 w.write_str("<h4 class=\"code-header\">");
1448 link.anchor(source_id.as_ref().unwrap_or(&id)),
1452 w.write_str("</h4>");
1453 w.write_str("</div>");
1456 clean::TypedefItem(ref tydef, _) => {
1457 let source_id = format!("{}.{}", ItemType::AssocType, name);
1458 let id = cx.derive_id(source_id.clone());
1461 "<div id=\"{}\" class=\"{}{} has-srclink\">",
1462 id, item_type, in_trait_class
1464 write!(w, "<a href=\"#{}\" class=\"anchor\"></a>", id);
1465 w.write_str("<h4 class=\"code-header\">");
1471 link.anchor(if trait_.is_some() { &source_id } else { &id }),
1475 w.write_str("</h4>");
1476 w.write_str("</div>");
1478 clean::AssocConstItem(ref ty, ref default) => {
1479 let source_id = format!("{}.{}", item_type, name);
1480 let id = cx.derive_id(source_id.clone());
1483 "<div id=\"{}\" class=\"{}{} has-srclink\">",
1484 id, item_type, in_trait_class
1486 render_rightside(w, cx, item, containing_item);
1487 write!(w, "<a href=\"#{}\" class=\"anchor\"></a>", id);
1488 w.write_str("<h4 class=\"code-header\">");
1494 link.anchor(if trait_.is_some() { &source_id } else { &id }),
1498 w.write_str("</h4>");
1499 w.write_str("</div>");
1501 clean::AssocTypeItem(ref bounds, ref default) => {
1502 let source_id = format!("{}.{}", item_type, name);
1503 let id = cx.derive_id(source_id.clone());
1504 write!(w, "<div id=\"{}\" class=\"{}{}\">", id, item_type, in_trait_class,);
1505 write!(w, "<a href=\"#{}\" class=\"anchor\"></a>", id);
1506 w.write_str("<h4 class=\"code-header\">");
1512 link.anchor(if trait_.is_some() { &source_id } else { &id }),
1516 w.write_str("</h4>");
1517 w.write_str("</div>");
1519 clean::StrippedItem(..) => return,
1520 _ => panic!("can't make docs for trait item with name {:?}", item.name),
1523 w.push_buffer(info_buffer);
1525 w.write_str("</summary>");
1526 w.push_buffer(doc_buffer);
1527 w.push_str("</details>");
1531 let mut impl_items = Buffer::empty_from(w);
1532 let mut default_impl_items = Buffer::empty_from(w);
1534 for trait_item in &i.inner_impl().items {
1536 &mut default_impl_items,
1540 if trait_.is_some() { &i.impl_item } else { parent },
1545 trait_.map(|t| &t.trait_),
1550 fn render_default_items(
1551 boring: &mut Buffer,
1552 interesting: &mut Buffer,
1556 parent: &clean::Item,
1557 containing_item: &clean::Item,
1558 render_mode: RenderMode,
1559 rendering_params: ImplRenderingParameters,
1561 for trait_item in &t.items {
1562 let n = trait_item.name;
1563 if i.items.iter().any(|m| m.name == n) {
1566 let did = i.trait_.as_ref().unwrap().def_id();
1567 let provided_methods = i.provided_trait_methods(cx.tcx());
1568 let assoc_link = AssocItemLink::GotoSource(did.into(), &provided_methods);
1586 // If we've implemented a trait, then also emit documentation for all
1587 // default items which weren't overridden in the implementation block.
1588 // We don't emit documentation for default items if they appear in the
1589 // Implementations on Foreign Types or Implementors sections.
1590 if rendering_params.show_default_items {
1591 if let Some(t) = trait_ {
1592 render_default_items(
1593 &mut default_impl_items,
1605 if render_mode == RenderMode::Normal {
1606 let toggled = !(impl_items.is_empty() && default_impl_items.is_empty());
1608 close_tags.insert_str(0, "</details>");
1611 "<details class=\"rustdoc-toggle implementors-toggle\"{}>",
1612 if rendering_params.toggle_open_by_default { " open" } else { "" }
1614 write!(w, "<summary>")
1616 render_impl_summary(
1622 rendering_params.show_def_docs,
1624 rendering_params.is_on_foreign_type,
1628 write!(w, "</summary>")
1631 if let Some(ref dox) = cx.shared.maybe_collapsed_doc_value(&i.impl_item) {
1632 let mut ids = cx.id_map.borrow_mut();
1635 "<div class=\"docblock\">{}</div>",
1638 links: &i.impl_item.links(cx),
1640 error_codes: cx.shared.codes,
1641 edition: cx.shared.edition(),
1642 playground: &cx.shared.playground,
1643 heading_offset: HeadingOffset::H4
1649 if !default_impl_items.is_empty() || !impl_items.is_empty() {
1650 w.write_str("<div class=\"impl-items\">");
1651 w.push_buffer(default_impl_items);
1652 w.push_buffer(impl_items);
1653 close_tags.insert_str(0, "</div>");
1655 w.write_str(&close_tags);
1658 // Render the items that appear on the right side of methods, impls, and
1659 // associated types. For example "1.0.0 (const: 1.39.0) [src]".
1660 fn render_rightside(
1664 containing_item: &clean::Item,
1668 write!(w, "<div class=\"rightside\">");
1669 render_stability_since_raw(
1671 item.stable_since(tcx).as_deref(),
1672 item.const_stability(tcx),
1673 containing_item.stable_since(tcx).as_deref(),
1674 containing_item.const_stable_since(tcx).as_deref(),
1677 write_srclink(cx, item, w);
1678 w.write_str("</div>");
1681 pub(crate) fn render_impl_summary(
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, "<div id=\"{}\" class=\"impl has-srclink\"{}>", id, aliases);
1710 render_rightside(w, cx, &i.impl_item, containing_item);
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::TypedefItem(ref tydef, _) = *it.kind {
1719 w.write_str("<span class=\"where fmt-newline\"> ");
1720 assoc_type(w, it, &[], Some(&tydef.type_), AssocItemLink::Anchor(None), "", cx);
1721 w.write_str(";</span>");
1726 write!(w, "{}", i.inner_impl().print(false, cx));
1730 let is_trait = i.inner_impl().trait_.is_some();
1732 if let Some(portability) = portability(&i.impl_item, Some(parent)) {
1733 write!(w, "<div class=\"item-info\">{}</div>", portability);
1737 w.write_str("</div>");
1740 fn print_sidebar(cx: &Context<'_>, it: &clean::Item, buffer: &mut Buffer) {
1741 let parentlen = cx.current.len() - if it.is_mod() { 1 } else { 0 };
1745 || it.is_primitive()
1753 "<h2 class=\"location\">{}{}</h2>",
1755 clean::StructItem(..) => "Struct ",
1756 clean::TraitItem(..) => "Trait ",
1757 clean::PrimitiveItem(..) => "Primitive Type ",
1758 clean::UnionItem(..) => "Union ",
1759 clean::EnumItem(..) => "Enum ",
1760 clean::TypedefItem(..) => "Type Definition ",
1761 clean::ForeignTypeItem => "Foreign Type ",
1762 clean::ModuleItem(..) =>
1770 it.name.as_ref().unwrap()
1775 if let Some(ref version) = cx.cache().crate_version {
1778 "<div class=\"block version\">\
1779 <div class=\"narrow-helper\"></div>\
1787 buffer.write_str("<div class=\"sidebar-elems\">");
1791 "<a id=\"all-types\" href=\"all.html\"><p>See all {}'s items</p></a>",
1792 it.name.as_ref().expect("crates always have a name"),
1797 clean::StructItem(ref s) => sidebar_struct(cx, buffer, it, s),
1798 clean::TraitItem(ref t) => sidebar_trait(cx, buffer, it, t),
1799 clean::PrimitiveItem(_) => sidebar_primitive(cx, buffer, it),
1800 clean::UnionItem(ref u) => sidebar_union(cx, buffer, it, u),
1801 clean::EnumItem(ref e) => sidebar_enum(cx, buffer, it, e),
1802 clean::TypedefItem(_, _) => sidebar_typedef(cx, buffer, it),
1803 clean::ModuleItem(ref m) => sidebar_module(buffer, &m.items),
1804 clean::ForeignTypeItem => sidebar_foreign_type(cx, buffer, it),
1808 // The sidebar is designed to display sibling functions, modules and
1809 // other miscellaneous information. since there are lots of sibling
1810 // items (and that causes quadratic growth in large modules),
1811 // we refactor common parts into a shared JavaScript file per module.
1812 // still, we don't move everything into JS because we want to preserve
1813 // as much HTML as possible in order to allow non-JS-enabled browsers
1814 // to navigate the documentation (though slightly inefficiently).
1817 buffer.write_str("<h2 class=\"location\">Other items in<br>");
1818 for (i, name) in cx.current.iter().take(parentlen).enumerate() {
1820 buffer.write_str("::<wbr>");
1824 "<a href=\"{}index.html\">{}</a>",
1825 &cx.root_path()[..(cx.current.len() - i - 1) * 3],
1829 buffer.write_str("</h2>");
1832 // Sidebar refers to the enclosing module, not this module.
1833 let relpath = if it.is_mod() && parentlen != 0 { "./" } else { "" };
1836 "<div id=\"sidebar-vars\" data-name=\"{name}\" data-ty=\"{ty}\" data-relpath=\"{path}\">\
1838 name = it.name.unwrap_or(kw::Empty),
1842 write!(buffer, "<script defer src=\"{}sidebar-items.js\"></script>", relpath);
1843 // Closes sidebar-elems div.
1844 buffer.write_str("</div>");
1847 fn get_next_url(used_links: &mut FxHashSet<String>, url: String) -> String {
1848 if used_links.insert(url.clone()) {
1852 while !used_links.insert(format!("{}-{}", url, add)) {
1855 format!("{}-{}", url, add)
1858 struct SidebarLink {
1863 impl fmt::Display for SidebarLink {
1864 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1865 write!(f, "<a href=\"#{}\">{}</a>", self.url, self.name)
1869 impl PartialEq for SidebarLink {
1870 fn eq(&self, other: &Self) -> bool {
1871 self.url == other.url
1875 impl Eq for SidebarLink {}
1877 impl PartialOrd for SidebarLink {
1878 fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
1879 Some(self.cmp(other))
1883 impl Ord for SidebarLink {
1884 fn cmp(&self, other: &Self) -> std::cmp::Ordering {
1885 self.url.cmp(&other.url)
1892 used_links: &mut FxHashSet<String>,
1895 ) -> Vec<SidebarLink> {
1898 .filter_map(|item| match item.name {
1899 Some(name) if !name.is_empty() && item.is_method() => {
1900 if !for_deref || should_render_item(item, deref_mut, tcx) {
1903 url: get_next_url(used_links, format!("method.{}", name)),
1911 .collect::<Vec<_>>()
1914 fn get_associated_constants(
1916 used_links: &mut FxHashSet<String>,
1917 ) -> Vec<SidebarLink> {
1920 .filter_map(|item| match item.name {
1921 Some(name) if !name.is_empty() && item.is_associated_const() => Some(SidebarLink {
1923 url: get_next_url(used_links, format!("associatedconstant.{}", name)),
1927 .collect::<Vec<_>>()
1930 // The point is to url encode any potential character from a type with genericity.
1931 fn small_url_encode(s: String) -> String {
1932 let mut st = String::new();
1933 let mut last_match = 0;
1934 for (idx, c) in s.char_indices() {
1935 let escaped = match c {
1951 st += &s[last_match..idx];
1953 // NOTE: we only expect single byte characters here - which is fine as long as we
1954 // only match single byte characters
1955 last_match = idx + 1;
1958 if last_match != 0 {
1959 st += &s[last_match..];
1966 fn sidebar_assoc_items(cx: &Context<'_>, out: &mut Buffer, it: &clean::Item) {
1967 let did = it.def_id.expect_def_id();
1968 let cache = cx.cache();
1969 if let Some(v) = cache.impls.get(&did) {
1970 let mut used_links = FxHashSet::default();
1973 let used_links_bor = &mut used_links;
1974 let mut assoc_consts = v
1976 .flat_map(|i| get_associated_constants(i.inner_impl(), used_links_bor))
1977 .collect::<Vec<_>>();
1978 if !assoc_consts.is_empty() {
1979 // We want links' order to be reproducible so we don't use unstable sort.
1980 assoc_consts.sort();
1983 "<h3 class=\"sidebar-title\">\
1984 <a href=\"#implementations\">Associated Constants</a>\
1986 <div class=\"sidebar-links\">",
1988 for line in assoc_consts {
1989 write!(out, "{}", line);
1991 out.push_str("</div>");
1995 .filter(|i| i.inner_impl().trait_.is_none())
1996 .flat_map(|i| get_methods(i.inner_impl(), false, used_links_bor, false, cx.tcx()))
1997 .collect::<Vec<_>>();
1998 if !methods.is_empty() {
1999 // We want links' order to be reproducible so we don't use unstable sort.
2003 "<h3 class=\"sidebar-title\"><a href=\"#implementations\">Methods</a></h3>\
2004 <div class=\"sidebar-links\">",
2006 for line in methods {
2007 write!(out, "{}", line);
2009 out.push_str("</div>");
2013 if v.iter().any(|i| i.inner_impl().trait_.is_some()) {
2014 if let Some(impl_) =
2015 v.iter().find(|i| i.trait_did() == cx.tcx().lang_items().deref_trait())
2017 let mut derefs = FxHashSet::default();
2019 sidebar_deref_methods(cx, out, impl_, v, &mut derefs);
2022 let format_impls = |impls: Vec<&Impl>| {
2023 let mut links = FxHashSet::default();
2028 if let Some(ref i) = it.inner_impl().trait_ {
2029 let i_display = format!("{:#}", i.print(cx));
2030 let out = Escape(&i_display);
2031 let encoded = small_url_encode(format!("{:#}", i.print(cx)));
2032 let prefix = match it.inner_impl().polarity {
2033 ty::ImplPolarity::Positive | ty::ImplPolarity::Reservation => "",
2034 ty::ImplPolarity::Negative => "!",
2037 format!("<a href=\"#impl-{}\">{}{}</a>", encoded, prefix, out);
2038 if links.insert(generated.clone()) { Some(generated) } else { None }
2043 .collect::<Vec<String>>();
2048 let write_sidebar_links = |out: &mut Buffer, links: Vec<String>| {
2049 out.push_str("<div class=\"sidebar-links\">");
2051 out.push_str(&link);
2053 out.push_str("</div>");
2056 let (synthetic, concrete): (Vec<&Impl>, Vec<&Impl>) =
2057 v.iter().partition::<Vec<_>, _>(|i| i.inner_impl().kind.is_auto());
2058 let (blanket_impl, concrete): (Vec<&Impl>, Vec<&Impl>) =
2059 concrete.into_iter().partition::<Vec<_>, _>(|i| i.inner_impl().kind.is_blanket());
2061 let concrete_format = format_impls(concrete);
2062 let synthetic_format = format_impls(synthetic);
2063 let blanket_format = format_impls(blanket_impl);
2065 if !concrete_format.is_empty() {
2067 "<h3 class=\"sidebar-title\"><a href=\"#trait-implementations\">\
2068 Trait Implementations</a></h3>",
2070 write_sidebar_links(out, concrete_format);
2073 if !synthetic_format.is_empty() {
2075 "<h3 class=\"sidebar-title\"><a href=\"#synthetic-implementations\">\
2076 Auto Trait Implementations</a></h3>",
2078 write_sidebar_links(out, synthetic_format);
2081 if !blanket_format.is_empty() {
2083 "<h3 class=\"sidebar-title\"><a href=\"#blanket-implementations\">\
2084 Blanket Implementations</a></h3>",
2086 write_sidebar_links(out, blanket_format);
2092 fn sidebar_deref_methods(
2097 derefs: &mut FxHashSet<DefId>,
2101 debug!("found Deref: {:?}", impl_);
2102 if let Some((target, real_target)) =
2103 impl_.inner_impl().items.iter().find_map(|item| match *item.kind {
2104 clean::TypedefItem(ref t, true) => Some(match *t {
2105 clean::Typedef { item_type: Some(ref type_), .. } => (type_, &t.type_),
2106 _ => (&t.type_, &t.type_),
2111 debug!("found target, real_target: {:?} {:?}", target, real_target);
2112 if let Some(did) = target.def_id(c) {
2113 if let Some(type_did) = impl_.inner_impl().for_.def_id(c) {
2114 // `impl Deref<Target = S> for S`
2115 if did == type_did || !derefs.insert(did) {
2116 // Avoid infinite cycles
2121 let deref_mut = v.iter().any(|i| i.trait_did() == cx.tcx().lang_items().deref_mut_trait());
2122 let inner_impl = target
2125 target.primitive_type().and_then(|prim| c.primitive_locations.get(&prim).cloned())
2127 .and_then(|did| c.impls.get(&did));
2128 if let Some(impls) = inner_impl {
2129 debug!("found inner_impl: {:?}", impls);
2130 let mut used_links = FxHashSet::default();
2133 .filter(|i| i.inner_impl().trait_.is_none())
2135 get_methods(i.inner_impl(), true, &mut used_links, deref_mut, cx.tcx())
2137 .collect::<Vec<_>>();
2138 if !ret.is_empty() {
2140 let id = if let Some(target_def_id) = real_target.def_id(c) {
2141 map = cx.deref_id_map.borrow();
2142 map.get(&target_def_id).expect("Deref section without derived id")
2148 "<h3 class=\"sidebar-title\"><a href=\"#{}\">Methods from {}<Target={}></a></h3>",
2150 Escape(&format!("{:#}", impl_.inner_impl().trait_.as_ref().unwrap().print(cx))),
2151 Escape(&format!("{:#}", real_target.print(cx))),
2153 // We want links' order to be reproducible so we don't use unstable sort.
2155 out.push_str("<div class=\"sidebar-links\">");
2157 write!(out, "{}", link);
2159 out.push_str("</div>");
2163 // Recurse into any further impls that might exist for `target`
2164 if let Some(target_did) = target.def_id_no_primitives() {
2165 if let Some(target_impls) = c.impls.get(&target_did) {
2166 if let Some(target_deref_impl) = target_impls.iter().find(|i| {
2170 .map(|t| Some(t.def_id()) == cx.tcx().lang_items().deref_trait())
2173 sidebar_deref_methods(cx, out, target_deref_impl, target_impls, derefs);
2180 fn sidebar_struct(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, s: &clean::Struct) {
2181 let mut sidebar = Buffer::new();
2182 let fields = get_struct_fields_name(&s.fields);
2184 if !fields.is_empty() {
2185 if let CtorKind::Fictive = s.struct_type {
2187 "<h3 class=\"sidebar-title\"><a href=\"#fields\">Fields</a></h3>\
2188 <div class=\"sidebar-links\">",
2191 for field in fields {
2192 sidebar.push_str(&field);
2195 sidebar.push_str("</div>");
2196 } else if let CtorKind::Fn = s.struct_type {
2198 .push_str("<h3 class=\"sidebar-title\"><a href=\"#fields\">Tuple Fields</a></h3>");
2202 sidebar_assoc_items(cx, &mut sidebar, it);
2204 if !sidebar.is_empty() {
2205 write!(buf, "<div class=\"block items\">{}</div>", sidebar.into_inner());
2209 fn get_id_for_impl_on_foreign_type(
2211 trait_: &clean::Path,
2214 small_url_encode(format!("impl-{:#}-for-{:#}", trait_.print(cx), for_.print(cx)))
2217 fn extract_for_impl_name(item: &clean::Item, cx: &Context<'_>) -> Option<(String, String)> {
2219 clean::ItemKind::ImplItem(ref i) => {
2220 i.trait_.as_ref().map(|trait_| {
2221 // Alternative format produces no URLs,
2222 // so this parameter does nothing.
2224 format!("{:#}", i.for_.print(cx)),
2225 get_id_for_impl_on_foreign_type(&i.for_, trait_, cx),
2233 fn sidebar_trait(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, t: &clean::Trait) {
2234 buf.write_str("<div class=\"block items\">");
2236 fn print_sidebar_section(
2238 items: &[clean::Item],
2240 filter: impl Fn(&clean::Item) -> bool,
2241 write: impl Fn(&mut Buffer, &str),
2244 let mut items = items
2246 .filter_map(|m| match m.name {
2247 Some(ref name) if filter(m) => Some(name.as_str()),
2250 .collect::<Vec<_>>();
2252 if !items.is_empty() {
2253 items.sort_unstable();
2254 out.push_str(before);
2255 for item in items.into_iter() {
2258 out.push_str(after);
2262 print_sidebar_section(
2265 "<h3 class=\"sidebar-title\"><a href=\"#associated-types\">\
2266 Associated Types</a></h3><div class=\"sidebar-links\">",
2267 |m| m.is_associated_type(),
2268 |out, sym| write!(out, "<a href=\"#associatedtype.{0}\">{0}</a>", sym),
2272 print_sidebar_section(
2275 "<h3 class=\"sidebar-title\"><a href=\"#associated-const\">\
2276 Associated Constants</a></h3><div class=\"sidebar-links\">",
2277 |m| m.is_associated_const(),
2278 |out, sym| write!(out, "<a href=\"#associatedconstant.{0}\">{0}</a>", sym),
2282 print_sidebar_section(
2285 "<h3 class=\"sidebar-title\"><a href=\"#required-methods\">\
2286 Required Methods</a></h3><div class=\"sidebar-links\">",
2287 |m| m.is_ty_method(),
2288 |out, sym| write!(out, "<a href=\"#tymethod.{0}\">{0}</a>", sym),
2292 print_sidebar_section(
2295 "<h3 class=\"sidebar-title\"><a href=\"#provided-methods\">\
2296 Provided Methods</a></h3><div class=\"sidebar-links\">",
2298 |out, sym| write!(out, "<a href=\"#method.{0}\">{0}</a>", sym),
2302 let cache = cx.cache();
2303 if let Some(implementors) = cache.implementors.get(&it.def_id.expect_def_id()) {
2304 let mut res = implementors
2307 i.inner_impl().for_.def_id(cache).map_or(false, |d| !cache.paths.contains_key(&d))
2309 .filter_map(|i| extract_for_impl_name(&i.impl_item, cx))
2310 .collect::<Vec<_>>();
2312 if !res.is_empty() {
2315 "<h3 class=\"sidebar-title\"><a href=\"#foreign-impls\">\
2316 Implementations on Foreign Types</a></h3>\
2317 <div class=\"sidebar-links\">",
2319 for (name, id) in res.into_iter() {
2320 write!(buf, "<a href=\"#{}\">{}</a>", id, Escape(&name));
2322 buf.push_str("</div>");
2326 sidebar_assoc_items(cx, buf, it);
2328 buf.push_str("<h3 class=\"sidebar-title\"><a href=\"#implementors\">Implementors</a></h3>");
2331 "<h3 class=\"sidebar-title\"><a \
2332 href=\"#synthetic-implementors\">Auto Implementors</a></h3>",
2336 buf.push_str("</div>")
2339 fn sidebar_primitive(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item) {
2340 let mut sidebar = Buffer::new();
2341 sidebar_assoc_items(cx, &mut sidebar, it);
2343 if !sidebar.is_empty() {
2344 write!(buf, "<div class=\"block items\">{}</div>", sidebar.into_inner());
2348 fn sidebar_typedef(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item) {
2349 let mut sidebar = Buffer::new();
2350 sidebar_assoc_items(cx, &mut sidebar, it);
2352 if !sidebar.is_empty() {
2353 write!(buf, "<div class=\"block items\">{}</div>", sidebar.into_inner());
2357 fn get_struct_fields_name(fields: &[clean::Item]) -> Vec<String> {
2358 let mut fields = fields
2360 .filter(|f| matches!(*f.kind, clean::StructFieldItem(..)))
2362 f.name.map(|name| format!("<a href=\"#structfield.{name}\">{name}</a>", name = name))
2364 .collect::<Vec<_>>();
2369 fn sidebar_union(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, u: &clean::Union) {
2370 let mut sidebar = Buffer::new();
2371 let fields = get_struct_fields_name(&u.fields);
2373 if !fields.is_empty() {
2375 "<h3 class=\"sidebar-title\"><a href=\"#fields\">Fields</a></h3>\
2376 <div class=\"sidebar-links\">",
2379 for field in fields {
2380 sidebar.push_str(&field);
2383 sidebar.push_str("</div>");
2386 sidebar_assoc_items(cx, &mut sidebar, it);
2388 if !sidebar.is_empty() {
2389 write!(buf, "<div class=\"block items\">{}</div>", sidebar.into_inner());
2393 fn sidebar_enum(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, e: &clean::Enum) {
2394 let mut sidebar = Buffer::new();
2396 let mut variants = e
2402 .map(|name| format!("<a href=\"#variant.{name}\">{name}</a>", name = name))
2404 .collect::<Vec<_>>();
2405 if !variants.is_empty() {
2406 variants.sort_unstable();
2407 sidebar.push_str(&format!(
2408 "<h3 class=\"sidebar-title\"><a href=\"#variants\">Variants</a></h3>\
2409 <div class=\"sidebar-links\">{}</div>",
2414 sidebar_assoc_items(cx, &mut sidebar, it);
2416 if !sidebar.is_empty() {
2417 write!(buf, "<div class=\"block items\">{}</div>", sidebar.into_inner());
2421 fn item_ty_to_strs(ty: ItemType) -> (&'static str, &'static str) {
2423 ItemType::ExternCrate | ItemType::Import => ("reexports", "Re-exports"),
2424 ItemType::Module => ("modules", "Modules"),
2425 ItemType::Struct => ("structs", "Structs"),
2426 ItemType::Union => ("unions", "Unions"),
2427 ItemType::Enum => ("enums", "Enums"),
2428 ItemType::Function => ("functions", "Functions"),
2429 ItemType::Typedef => ("types", "Type Definitions"),
2430 ItemType::Static => ("statics", "Statics"),
2431 ItemType::Constant => ("constants", "Constants"),
2432 ItemType::Trait => ("traits", "Traits"),
2433 ItemType::Impl => ("impls", "Implementations"),
2434 ItemType::TyMethod => ("tymethods", "Type Methods"),
2435 ItemType::Method => ("methods", "Methods"),
2436 ItemType::StructField => ("fields", "Struct Fields"),
2437 ItemType::Variant => ("variants", "Variants"),
2438 ItemType::Macro => ("macros", "Macros"),
2439 ItemType::Primitive => ("primitives", "Primitive Types"),
2440 ItemType::AssocType => ("associated-types", "Associated Types"),
2441 ItemType::AssocConst => ("associated-consts", "Associated Constants"),
2442 ItemType::ForeignType => ("foreign-types", "Foreign Types"),
2443 ItemType::Keyword => ("keywords", "Keywords"),
2444 ItemType::OpaqueTy => ("opaque-types", "Opaque Types"),
2445 ItemType::ProcAttribute => ("attributes", "Attribute Macros"),
2446 ItemType::ProcDerive => ("derives", "Derive Macros"),
2447 ItemType::TraitAlias => ("trait-aliases", "Trait aliases"),
2448 ItemType::Generic => unreachable!(),
2452 fn sidebar_module(buf: &mut Buffer, items: &[clean::Item]) {
2453 let mut sidebar = String::new();
2455 // Re-exports are handled a bit differently because they can be extern crates or imports.
2456 if items.iter().any(|it| {
2458 && (it.type_() == ItemType::ExternCrate
2459 || (it.type_() == ItemType::Import && !it.is_stripped()))
2461 let (id, name) = item_ty_to_strs(ItemType::Import);
2462 sidebar.push_str(&format!("<li><a href=\"#{}\">{}</a></li>", id, name));
2465 // ordering taken from item_module, reorder, where it prioritized elements in a certain order
2466 // to print its headings
2468 ItemType::Primitive,
2482 ItemType::StructField,
2484 ItemType::AssocType,
2485 ItemType::AssocConst,
2486 ItemType::ForeignType,
2489 if items.iter().any(|it| !it.is_stripped() && it.type_() == myty && it.name.is_some()) {
2490 let (id, name) = item_ty_to_strs(myty);
2491 sidebar.push_str(&format!("<li><a href=\"#{}\">{}</a></li>", id, name));
2495 if !sidebar.is_empty() {
2496 write!(buf, "<div class=\"block items\"><ul>{}</ul></div>", sidebar);
2500 fn sidebar_foreign_type(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item) {
2501 let mut sidebar = Buffer::new();
2502 sidebar_assoc_items(cx, &mut sidebar, it);
2504 if !sidebar.is_empty() {
2505 write!(buf, "<div class=\"block items\">{}</div>", sidebar.into_inner());
2509 crate const BASIC_KEYWORDS: &str = "rust, rustlang, rust-lang";
2511 /// Returns a list of all paths used in the type.
2512 /// This is used to help deduplicate imported impls
2513 /// for reexported types. If any of the contained
2514 /// types are re-exported, we don't use the corresponding
2515 /// entry from the js file, as inlining will have already
2516 /// picked up the impl
2517 fn collect_paths_for_type(first_ty: clean::Type, cache: &Cache) -> Vec<String> {
2518 let mut out = Vec::new();
2519 let mut visited = FxHashSet::default();
2520 let mut work = VecDeque::new();
2522 let mut process_path = |did: DefId| {
2523 let get_extern = || cache.external_paths.get(&did).map(|s| s.0.clone());
2524 let fqp = cache.exact_paths.get(&did).cloned().or_else(get_extern);
2526 if let Some(path) = fqp {
2527 out.push(path.join("::"));
2531 work.push_back(first_ty);
2533 while let Some(ty) = work.pop_front() {
2534 if !visited.insert(ty.clone()) {
2539 clean::Type::ResolvedPath { did, .. } => process_path(did),
2540 clean::Type::Tuple(tys) => {
2541 work.extend(tys.into_iter());
2543 clean::Type::Slice(ty) => {
2544 work.push_back(*ty);
2546 clean::Type::Array(ty, _) => {
2547 work.push_back(*ty);
2549 clean::Type::RawPointer(_, ty) => {
2550 work.push_back(*ty);
2552 clean::Type::BorrowedRef { type_, .. } => {
2553 work.push_back(*type_);
2555 clean::Type::QPath { self_type, trait_, .. } => {
2556 work.push_back(*self_type);
2557 process_path(trait_.def_id());
2565 const MAX_FULL_EXAMPLES: usize = 5;
2566 const NUM_VISIBLE_LINES: usize = 10;
2568 /// Generates the HTML for example call locations generated via the --scrape-examples flag.
2569 fn render_call_locations(w: &mut Buffer, cx: &Context<'_>, item: &clean::Item) {
2571 let def_id = item.def_id.expect_def_id();
2572 let key = tcx.def_path_hash(def_id);
2573 let call_locations = match cx.shared.call_locations.get(&key) {
2574 Some(call_locations) => call_locations,
2580 // Generate a unique ID so users can link to this section for a given method
2581 let id = cx.id_map.borrow_mut().derive("scraped-examples");
2584 "<div class=\"docblock scraped-example-list\">\
2586 <h5 id=\"{id}\" class=\"section-header\">\
2587 <a href=\"#{id}\">Examples found in repository</a>\
2592 // Create a URL to a particular location in a reverse-dependency's source file
2593 let link_to_loc = |call_data: &CallData, loc: &CallLocation| -> (String, String) {
2594 let (line_lo, line_hi) = loc.call_expr.line_span;
2595 let (anchor, title) = if line_lo == line_hi {
2596 ((line_lo + 1).to_string(), format!("line {}", line_lo + 1))
2599 format!("{}-{}", line_lo + 1, line_hi + 1),
2600 format!("lines {}-{}", line_lo + 1, line_hi + 1),
2603 let url = format!("{}{}#{}", cx.root_path(), call_data.url, anchor);
2607 // Generate the HTML for a single example, being the title and code block
2608 let write_example = |w: &mut Buffer, (path, call_data): (&PathBuf, &CallData)| -> bool {
2609 let contents = match fs::read_to_string(&path) {
2610 Ok(contents) => contents,
2612 let span = item.span(tcx).inner();
2614 .span_err(span, &format!("failed to read file {}: {}", path.display(), err));
2619 // To reduce file sizes, we only want to embed the source code needed to understand the example, not
2620 // the entire file. So we find the smallest byte range that covers all items enclosing examples.
2621 assert!(!call_data.locations.is_empty());
2623 call_data.locations.iter().min_by_key(|loc| loc.enclosing_item.byte_span.0).unwrap();
2624 let byte_min = min_loc.enclosing_item.byte_span.0;
2625 let line_min = min_loc.enclosing_item.line_span.0;
2627 call_data.locations.iter().max_by_key(|loc| loc.enclosing_item.byte_span.1).unwrap();
2628 let byte_max = max_loc.enclosing_item.byte_span.1;
2629 let line_max = max_loc.enclosing_item.line_span.1;
2631 // The output code is limited to that byte range.
2632 let contents_subset = &contents[(byte_min as usize)..(byte_max as usize)];
2634 // The call locations need to be updated to reflect that the size of the program has changed.
2635 // Specifically, the ranges are all subtracted by `byte_min` since that's the new zero point.
2636 let (mut byte_ranges, line_ranges): (Vec<_>, Vec<_>) = call_data
2640 let (byte_lo, byte_hi) = loc.call_expr.byte_span;
2641 let (line_lo, line_hi) = loc.call_expr.line_span;
2642 let byte_range = (byte_lo - byte_min, byte_hi - byte_min);
2643 let line_range = (line_lo - line_min, line_hi - line_min);
2644 let (line_url, line_title) = link_to_loc(call_data, loc);
2646 (byte_range, (line_range, line_url, line_title))
2650 let (_, init_url, init_title) = &line_ranges[0];
2651 let needs_expansion = line_max - line_min > NUM_VISIBLE_LINES;
2652 let locations_encoded = serde_json::to_string(&line_ranges).unwrap();
2656 "<div class=\"scraped-example {expanded_cls}\" data-locs=\"{locations}\">\
2657 <div class=\"scraped-example-title\">\
2658 {name} (<a href=\"{url}\">{title}</a>)\
2660 <div class=\"code-wrapper\">",
2661 expanded_cls = if needs_expansion { "" } else { "expanded" },
2662 name = call_data.display_name,
2665 // The locations are encoded as a data attribute, so they can be read
2666 // later by the JS for interactions.
2667 locations = Escape(&locations_encoded)
2670 if line_ranges.len() > 1 {
2671 write!(w, r#"<span class="prev">≺</span> <span class="next">≻</span>"#);
2674 if needs_expansion {
2675 write!(w, r#"<span class="expand">↕</span>"#);
2678 // Look for the example file in the source map if it exists, otherwise return a dummy span
2679 let file_span = (|| {
2680 let source_map = tcx.sess.source_map();
2681 let crate_src = tcx.sess.local_crate_source_file.as_ref()?;
2682 let abs_crate_src = crate_src.canonicalize().ok()?;
2683 let crate_root = abs_crate_src.parent()?.parent()?;
2684 let rel_path = path.strip_prefix(crate_root).ok()?;
2685 let files = source_map.files();
2686 let file = files.iter().find(|file| match &file.name {
2687 FileName::Real(RealFileName::LocalPath(other_path)) => rel_path == other_path,
2690 Some(rustc_span::Span::with_root_ctxt(
2691 file.start_pos + BytePos(byte_min),
2692 file.start_pos + BytePos(byte_max),
2695 .unwrap_or(rustc_span::DUMMY_SP);
2697 // The root path is the inverse of Context::current
2698 let root_path = vec!["../"; cx.current.len() - 1].join("");
2700 let mut decoration_info = FxHashMap::default();
2701 decoration_info.insert("highlight focus", vec![byte_ranges.remove(0)]);
2702 decoration_info.insert("highlight", byte_ranges);
2711 Some(highlight::DecorationInfo(decoration_info)),
2712 sources::SourceContext::Embedded { offset: line_min },
2714 write!(w, "</div></div>");
2719 // The call locations are output in sequence, so that sequence needs to be determined.
2720 // Ideally the most "relevant" examples would be shown first, but there's no general algorithm
2721 // for determining relevance. Instead, we prefer the smallest examples being likely the easiest to
2722 // understand at a glance.
2723 let ordered_locations = {
2724 let sort_criterion = |(_, call_data): &(_, &CallData)| {
2725 // Use the first location because that's what the user will see initially
2726 let (lo, hi) = call_data.locations[0].enclosing_item.byte_span;
2730 let mut locs = call_locations.into_iter().collect::<Vec<_>>();
2731 locs.sort_by_key(sort_criterion);
2735 let mut it = ordered_locations.into_iter().peekable();
2737 // An example may fail to write if its source can't be read for some reason, so this method
2738 // continues iterating until a write suceeds
2739 let write_and_skip_failure = |w: &mut Buffer, it: &mut Peekable<_>| {
2740 while let Some(example) = it.next() {
2741 if write_example(&mut *w, example) {
2747 // Write just one example that's visible by default in the method's description.
2748 write_and_skip_failure(w, &mut it);
2750 // Then add the remaining examples in a hidden section.
2751 if it.peek().is_some() {
2754 "<details class=\"rustdoc-toggle more-examples-toggle\">\
2755 <summary class=\"hideme\">\
2756 <span>More examples</span>\
2758 <div class=\"more-scraped-examples\">\
2759 <div class=\"toggle-line\"><div class=\"toggle-line-inner\"></div></div>\
2760 <div class=\"more-scraped-examples-inner\">"
2763 // Only generate inline code for MAX_FULL_EXAMPLES number of examples. Otherwise we could
2764 // make the page arbitrarily huge!
2765 for _ in 0..MAX_FULL_EXAMPLES {
2766 write_and_skip_failure(w, &mut it);
2769 // For the remaining examples, generate a <ul> containing links to the source files.
2770 if it.peek().is_some() {
2771 write!(w, r#"<div class="example-links">Additional examples can be found in:<br><ul>"#);
2772 it.for_each(|(_, call_data)| {
2773 let (url, _) = link_to_loc(&call_data, &call_data.locations[0]);
2776 r#"<li><a href="{url}">{name}</a></li>"#,
2778 name = call_data.display_name
2781 write!(w, "</ul></div>");
2784 write!(w, "</div></div></details>");
2787 write!(w, "</div>");