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::error::Error;
68 use crate::formats::cache::Cache;
69 use crate::formats::item_type::ItemType;
70 use crate::formats::{AssocItemRender, Impl, RenderMode};
71 use crate::html::escape::Escape;
72 use crate::html::format::{
73 href, print_abi_with_space, print_constness_with_space, print_default_space,
74 print_generic_bounds, print_where_clause, Buffer, HrefError, PrintWithSpace,
76 use crate::html::highlight;
77 use crate::html::markdown::{HeadingOffset, Markdown, MarkdownHtml, MarkdownSummaryLine};
78 use crate::html::sources;
79 use crate::scrape_examples::{CallData, CallLocation};
82 /// A pair of name and its optional document.
83 crate type NameDoc = (String, Option<String>);
85 crate fn ensure_trailing_slash(v: &str) -> impl fmt::Display + '_ {
86 crate::html::format::display_fn(move |f| {
87 if !v.ends_with('/') && !v.is_empty() { write!(f, "{}/", v) } else { f.write_str(v) }
91 // Helper structs for rendering items/sidebars and carrying along contextual
94 /// Struct representing one entry in the JS search index. These are all emitted
95 /// by hand to a large JS file at the end of cache-creation.
97 crate struct IndexItem {
102 crate parent: Option<DefId>,
103 crate parent_idx: Option<usize>,
104 crate search_type: Option<IndexItemFunctionType>,
105 crate aliases: Box<[Symbol]>,
108 /// A type used for the search index.
110 crate struct RenderType {
111 name: Option<String>,
112 generics: Option<Vec<TypeWithKind>>,
115 /// Full type of functions/methods in the search index.
117 crate struct IndexItemFunctionType {
118 inputs: Vec<TypeWithKind>,
119 output: Vec<TypeWithKind>,
122 impl Serialize for IndexItemFunctionType {
123 fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
127 // If we couldn't figure out a type, just write `null`.
128 let has_missing = self.inputs.iter().chain(self.output.iter()).any(|i| i.ty.name.is_none());
130 serializer.serialize_none()
132 let mut seq = serializer.serialize_seq(None)?;
133 seq.serialize_element(&self.inputs)?;
134 match self.output.as_slice() {
136 [one] => seq.serialize_element(one)?,
137 all => seq.serialize_element(all)?,
145 crate struct TypeWithKind {
150 impl From<(RenderType, ItemType)> for TypeWithKind {
151 fn from(x: (RenderType, ItemType)) -> TypeWithKind {
152 TypeWithKind { ty: x.0, kind: x.1 }
156 impl Serialize for TypeWithKind {
157 fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
161 let mut seq = serializer.serialize_seq(None)?;
162 seq.serialize_element(&self.ty.name)?;
163 seq.serialize_element(&self.kind)?;
164 if let Some(generics) = &self.ty.generics {
165 seq.serialize_element(generics)?;
171 #[derive(Debug, Clone)]
172 crate struct StylePath {
173 /// The path to the theme
178 pub fn basename(&self) -> Result<String, Error> {
179 Ok(try_none!(try_none!(self.path.file_stem(), &self.path).to_str(), &self.path).to_string())
183 fn write_srclink(cx: &Context<'_>, item: &clean::Item, buf: &mut Buffer) {
184 if let Some(l) = cx.src_href(item) {
185 write!(buf, "<a class=\"srclink\" href=\"{}\" title=\"goto source code\">[src]</a>", l)
189 #[derive(Debug, Eq, PartialEq, Hash)]
196 fn new(mut url: String, name: String) -> ItemEntry {
197 while url.starts_with('/') {
200 ItemEntry { url, name }
205 crate fn print(&self) -> impl fmt::Display + '_ {
206 crate::html::format::display_fn(move |f| {
207 write!(f, "<a href=\"{}\">{}</a>", self.url, Escape(&self.name))
212 impl PartialOrd for ItemEntry {
213 fn partial_cmp(&self, other: &ItemEntry) -> Option<::std::cmp::Ordering> {
214 Some(self.cmp(other))
218 impl Ord for ItemEntry {
219 fn cmp(&self, other: &ItemEntry) -> ::std::cmp::Ordering {
220 self.name.cmp(&other.name)
226 structs: FxHashSet<ItemEntry>,
227 enums: FxHashSet<ItemEntry>,
228 unions: FxHashSet<ItemEntry>,
229 primitives: FxHashSet<ItemEntry>,
230 traits: FxHashSet<ItemEntry>,
231 macros: FxHashSet<ItemEntry>,
232 functions: FxHashSet<ItemEntry>,
233 typedefs: FxHashSet<ItemEntry>,
234 opaque_tys: FxHashSet<ItemEntry>,
235 statics: FxHashSet<ItemEntry>,
236 constants: FxHashSet<ItemEntry>,
237 attributes: FxHashSet<ItemEntry>,
238 derives: FxHashSet<ItemEntry>,
239 trait_aliases: FxHashSet<ItemEntry>,
243 fn new() -> AllTypes {
244 let new_set = |cap| FxHashSet::with_capacity_and_hasher(cap, Default::default());
246 structs: new_set(100),
248 unions: new_set(100),
249 primitives: new_set(26),
250 traits: new_set(100),
251 macros: new_set(100),
252 functions: new_set(100),
253 typedefs: new_set(100),
254 opaque_tys: new_set(100),
255 statics: new_set(100),
256 constants: new_set(100),
257 attributes: new_set(100),
258 derives: new_set(100),
259 trait_aliases: new_set(100),
263 fn append(&mut self, item_name: String, item_type: &ItemType) {
264 let mut url: Vec<_> = item_name.split("::").skip(1).collect();
265 if let Some(name) = url.pop() {
266 let new_url = format!("{}/{}.{}.html", url.join("/"), item_type, name);
268 let name = url.join("::");
270 ItemType::Struct => self.structs.insert(ItemEntry::new(new_url, name)),
271 ItemType::Enum => self.enums.insert(ItemEntry::new(new_url, name)),
272 ItemType::Union => self.unions.insert(ItemEntry::new(new_url, name)),
273 ItemType::Primitive => self.primitives.insert(ItemEntry::new(new_url, name)),
274 ItemType::Trait => self.traits.insert(ItemEntry::new(new_url, name)),
275 ItemType::Macro => self.macros.insert(ItemEntry::new(new_url, name)),
276 ItemType::Function => self.functions.insert(ItemEntry::new(new_url, name)),
277 ItemType::Typedef => self.typedefs.insert(ItemEntry::new(new_url, name)),
278 ItemType::OpaqueTy => self.opaque_tys.insert(ItemEntry::new(new_url, name)),
279 ItemType::Static => self.statics.insert(ItemEntry::new(new_url, name)),
280 ItemType::Constant => self.constants.insert(ItemEntry::new(new_url, name)),
281 ItemType::ProcAttribute => self.attributes.insert(ItemEntry::new(new_url, name)),
282 ItemType::ProcDerive => self.derives.insert(ItemEntry::new(new_url, name)),
283 ItemType::TraitAlias => self.trait_aliases.insert(ItemEntry::new(new_url, name)),
291 fn print(self, f: &mut Buffer) {
292 fn print_entries(f: &mut Buffer, e: &FxHashSet<ItemEntry>, title: &str, class: &str) {
294 let mut e: Vec<&ItemEntry> = e.iter().collect();
298 "<h3 id=\"{}\">{}</h3><ul class=\"{} docblock\">",
299 title.replace(' ', "-"), // IDs cannot contain whitespaces.
305 write!(f, "<li>{}</li>", s.print());
308 f.write_str("</ul>");
314 <span class=\"in-band\">List of all items</span>\
315 <span class=\"out-of-band\">\
316 <span id=\"render-detail\">\
317 <a id=\"toggle-all-docs\" href=\"javascript:void(0)\" \
318 title=\"collapse all docs\">\
319 [<span class=\"inner\">−</span>]\
325 // Note: print_entries does not escape the title, because we know the current set of titles
326 // doesn't require escaping.
327 print_entries(f, &self.structs, "Structs", "structs");
328 print_entries(f, &self.enums, "Enums", "enums");
329 print_entries(f, &self.unions, "Unions", "unions");
330 print_entries(f, &self.primitives, "Primitives", "primitives");
331 print_entries(f, &self.traits, "Traits", "traits");
332 print_entries(f, &self.macros, "Macros", "macros");
333 print_entries(f, &self.attributes, "Attribute Macros", "attributes");
334 print_entries(f, &self.derives, "Derive Macros", "derives");
335 print_entries(f, &self.functions, "Functions", "functions");
336 print_entries(f, &self.typedefs, "Typedefs", "typedefs");
337 print_entries(f, &self.trait_aliases, "Trait Aliases", "trait-aliases");
338 print_entries(f, &self.opaque_tys, "Opaque Types", "opaque-types");
339 print_entries(f, &self.statics, "Statics", "statics");
340 print_entries(f, &self.constants, "Constants", "constants")
347 description: &'static str,
348 sub_settings: Vec<Setting>,
351 js_data_name: &'static str,
352 description: &'static str,
356 js_data_name: &'static str,
357 description: &'static str,
358 default_value: &'static str,
359 options: Vec<String>,
364 fn display(&self, root_path: &str, suffix: &str) -> String {
366 Setting::Section { description, ref sub_settings } => format!(
367 "<div class=\"setting-line\">\
368 <div class=\"title\">{}</div>\
369 <div class=\"sub-settings\">{}</div>
372 sub_settings.iter().map(|s| s.display(root_path, suffix)).collect::<String>()
374 Setting::Toggle { js_data_name, description, default_value } => format!(
375 "<div class=\"setting-line\">\
376 <label class=\"toggle\">\
377 <input type=\"checkbox\" id=\"{}\" {}>\
378 <span class=\"slider\"></span>\
383 if default_value { " checked" } else { "" },
386 Setting::Select { js_data_name, description, default_value, ref options } => format!(
387 "<div class=\"setting-line\">\
389 <label class=\"select-wrapper\">\
390 <select id=\"{}\" autocomplete=\"off\">{}</select>\
391 <img src=\"{}down-arrow{}.svg\" alt=\"Select item\">\
399 "<option value=\"{name}\" {}>{name}</option>",
400 if opt == default_value { "selected" } else { "" },
403 .collect::<String>(),
411 impl From<(&'static str, &'static str, bool)> for Setting {
412 fn from(values: (&'static str, &'static str, bool)) -> Setting {
413 Setting::Toggle { js_data_name: values.0, description: values.1, default_value: values.2 }
417 impl<T: Into<Setting>> From<(&'static str, Vec<T>)> for Setting {
418 fn from(values: (&'static str, Vec<T>)) -> Setting {
420 description: values.0,
421 sub_settings: values.1.into_iter().map(|v| v.into()).collect::<Vec<_>>(),
426 fn settings(root_path: &str, suffix: &str, theme_names: Vec<String>) -> Result<String, Error> {
427 // (id, explanation, default value)
428 let settings: &[Setting] = &[
432 Setting::from(("use-system-theme", "Use system theme", true)),
434 js_data_name: "preferred-dark-theme",
435 description: "Preferred dark theme",
436 default_value: "dark",
437 options: theme_names.clone(),
440 js_data_name: "preferred-light-theme",
441 description: "Preferred light theme",
442 default_value: "light",
443 options: theme_names,
448 ("auto-hide-large-items", "Auto-hide item contents for large items.", true).into(),
449 ("auto-hide-method-docs", "Auto-hide item methods' documentation", false).into(),
450 ("auto-hide-trait-implementations", "Auto-hide trait implementation documentation", false)
452 ("go-to-only-result", "Directly go to item in search if there is only one result", false)
454 ("line-numbers", "Show line numbers on code examples", false).into(),
455 ("disable-shortcuts", "Disable keyboard shortcuts", false).into(),
460 <span class=\"in-band\">Rustdoc settings</span>\
462 <div class=\"settings\">{}</div>\
463 <link rel=\"stylesheet\" href=\"{root_path}settings{suffix}.css\">\
464 <script src=\"{root_path}settings{suffix}.js\"></script>",
465 settings.iter().map(|s| s.display(root_path, suffix)).collect::<String>(),
466 root_path = root_path,
475 parent: Option<&clean::Item>,
476 heading_offset: HeadingOffset,
478 if let Some(ref name) = item.name {
479 info!("Documenting {}", name);
481 document_item_info(w, cx, item, parent);
482 if parent.is_none() {
483 document_full_collapsible(w, item, cx, heading_offset);
485 document_full(w, item, cx, heading_offset);
489 /// Render md_text as markdown.
494 links: Vec<RenderedLink>,
495 heading_offset: HeadingOffset,
497 let mut ids = cx.id_map.borrow_mut();
500 "<div class=\"docblock\">{}</div>",
505 error_codes: cx.shared.codes,
506 edition: cx.shared.edition(),
507 playground: &cx.shared.playground,
514 /// Writes a documentation block containing only the first paragraph of the documentation. If the
515 /// docs are longer, a "Read more" link is appended to the end.
520 link: AssocItemLink<'_>,
521 parent: &clean::Item,
524 document_item_info(w, cx, item, Some(parent));
528 if let Some(s) = item.doc_value() {
529 let mut summary_html = MarkdownSummaryLine(&s, &item.links(cx)).into_string();
531 if s.contains('\n') {
532 let link = format!(r#" <a href="{}">Read more</a>"#, naive_assoc_href(item, link, cx));
534 if let Some(idx) = summary_html.rfind("</p>") {
535 summary_html.insert_str(idx, &link);
537 summary_html.push_str(&link);
541 write!(w, "<div class='docblock'>{}</div>", summary_html,);
545 fn document_full_collapsible(
549 heading_offset: HeadingOffset,
551 document_full_inner(w, item, cx, true, heading_offset);
558 heading_offset: HeadingOffset,
560 document_full_inner(w, item, cx, false, heading_offset);
563 fn document_full_inner(
567 is_collapsible: bool,
568 heading_offset: HeadingOffset,
570 if let Some(s) = item.collapsed_doc_value() {
571 debug!("Doc block: =====\n{}\n=====", s);
574 "<details class=\"rustdoc-toggle top-doc\" open>\
575 <summary class=\"hideme\">\
576 <span>Expand description</span>\
579 render_markdown(w, cx, &s, item.links(cx), heading_offset);
580 w.write_str("</details>");
582 render_markdown(w, cx, &s, item.links(cx), heading_offset);
586 let kind = match &*item.kind {
587 clean::ItemKind::StrippedItem(box kind) | kind => kind,
590 if let clean::ItemKind::FunctionItem(..) | clean::ItemKind::MethodItem(..) = kind {
591 render_call_locations(w, cx, item);
595 /// Add extra information about an item such as:
599 /// * Required features (through the `doc_cfg` feature)
600 fn document_item_info(
604 parent: Option<&clean::Item>,
606 let item_infos = short_item_info(item, cx, parent);
607 if !item_infos.is_empty() {
608 w.write_str("<div class=\"item-info\">");
609 for info in item_infos {
612 w.write_str("</div>");
616 fn portability(item: &clean::Item, parent: Option<&clean::Item>) -> Option<String> {
617 let cfg = match (&item.cfg, parent.and_then(|p| p.cfg.as_ref())) {
618 (Some(cfg), Some(parent_cfg)) => cfg.simplify_with(parent_cfg),
619 (cfg, _) => cfg.as_deref().cloned(),
622 debug!("Portability {:?} - {:?} = {:?}", item.cfg, parent.and_then(|p| p.cfg.as_ref()), cfg);
624 Some(format!("<div class=\"stab portability\">{}</div>", cfg?.render_long_html()))
627 /// Render the stability, deprecation and portability information that is displayed at the top of
628 /// the item's documentation.
632 parent: Option<&clean::Item>,
634 let mut extra_info = vec![];
635 let error_codes = cx.shared.codes;
637 if let Some(depr @ Deprecation { note, since, is_since_rustc_version: _, suggestion: _ }) =
638 item.deprecation(cx.tcx())
640 // We display deprecation messages for #[deprecated] and #[rustc_deprecated]
641 // but only display the future-deprecation messages for #[rustc_deprecated].
642 let mut message = if let Some(since) = since {
643 let since = since.as_str();
644 if !stability::deprecation_in_effect(&depr) {
646 String::from("Deprecating in a future Rust version")
648 format!("Deprecating in {}", Escape(since))
651 format!("Deprecated since {}", Escape(since))
654 String::from("Deprecated")
657 if let Some(note) = note {
658 let note = note.as_str();
659 let mut ids = cx.id_map.borrow_mut();
660 let html = MarkdownHtml(
665 &cx.shared.playground,
667 message.push_str(&format!(": {}", html.into_string()));
669 extra_info.push(format!(
670 "<div class=\"stab deprecated\"><span class=\"emoji\">👎</span> {}</div>",
675 // Render unstable items. But don't render "rustc_private" crates (internal compiler crates).
676 // Those crates are permanently unstable so it makes no sense to render "unstable" everywhere.
677 if let Some((StabilityLevel::Unstable { reason: _, issue, .. }, feature)) = item
680 .filter(|stab| stab.feature != sym::rustc_private)
681 .map(|stab| (stab.level, stab.feature))
684 "<span class=\"emoji\">🔬</span> This is a nightly-only experimental API.".to_owned();
686 let mut feature = format!("<code>{}</code>", Escape(feature.as_str()));
687 if let (Some(url), Some(issue)) = (&cx.shared.issue_tracker_base_url, issue) {
688 feature.push_str(&format!(
689 " <a href=\"{url}{issue}\">#{issue}</a>",
695 message.push_str(&format!(" ({})", feature));
697 extra_info.push(format!("<div class=\"stab unstable\">{}</div>", message));
700 if let Some(portability) = portability(item, parent) {
701 extra_info.push(portability);
707 // Render the list of items inside one of the sections "Trait Implementations",
708 // "Auto Trait Implementations," "Blanket Trait Implementations" (on struct/enum pages).
709 fn render_impls(cx: &Context<'_>, w: &mut Buffer, impls: &[&&Impl], containing_item: &clean::Item) {
711 let mut rendered_impls = impls
714 let did = i.trait_did().unwrap();
715 let provided_trait_methods = i.inner_impl().provided_trait_methods(tcx);
716 let assoc_link = AssocItemLink::GotoSource(did.into(), &provided_trait_methods);
717 let mut buffer = if w.is_for_html() { Buffer::html() } else { Buffer::new() };
727 ImplRenderingParameters {
729 is_on_foreign_type: false,
730 show_default_items: true,
731 show_non_assoc_items: true,
732 toggle_open_by_default: true,
737 .collect::<Vec<_>>();
738 rendered_impls.sort();
739 w.write_str(&rendered_impls.join(""));
742 fn naive_assoc_href(it: &clean::Item, link: AssocItemLink<'_>, cx: &Context<'_>) -> String {
743 use crate::formats::item_type::ItemType::*;
745 let name = it.name.as_ref().unwrap();
746 let ty = match it.type_() {
747 Typedef | AssocType => AssocType,
751 let anchor = format!("#{}.{}", ty, name);
753 AssocItemLink::Anchor(Some(ref id)) => format!("#{}", id),
754 AssocItemLink::Anchor(None) => anchor,
755 AssocItemLink::GotoSource(did, _) => {
756 href(did.expect_def_id(), cx).map(|p| format!("{}{}", p.0, anchor)).unwrap_or(anchor)
765 link: AssocItemLink<'_>,
771 "{}{}const <a href=\"{}\" class=\"constant\">{}</a>: {}",
773 it.visibility.print_with_space(it.def_id, cx),
774 naive_assoc_href(it, link, cx),
775 it.name.as_ref().unwrap(),
783 bounds: &[clean::GenericBound],
784 default: Option<&clean::Type>,
785 link: AssocItemLink<'_>,
791 "{}type <a href=\"{}\" class=\"type\">{}</a>",
793 naive_assoc_href(it, link, cx),
794 it.name.as_ref().unwrap()
796 if !bounds.is_empty() {
797 write!(w, ": {}", print_generic_bounds(bounds, cx))
799 if let Some(default) = default {
800 write!(w, " = {}", default.print(cx))
804 fn render_stability_since_raw(
807 const_stability: Option<ConstStability>,
808 containing_ver: Option<Symbol>,
809 containing_const_ver: Option<Symbol>,
811 let ver = ver.filter(|inner| !inner.is_empty());
813 match (ver, const_stability) {
814 // stable and const stable
815 (Some(v), Some(ConstStability { level: StabilityLevel::Stable { since }, .. }))
816 if Some(since) != containing_const_ver =>
820 "<span class=\"since\" title=\"Stable since Rust version {0}, const since {1}\">{0} (const: {1})</span>",
824 // stable and const unstable
827 Some(ConstStability { level: StabilityLevel::Unstable { issue, .. }, feature, .. }),
831 "<span class=\"since\" title=\"Stable since Rust version {0}, const unstable\">{0} (const: ",
834 if let Some(n) = issue {
837 "<a href=\"https://github.com/rust-lang/rust/issues/{}\" title=\"Tracking issue for {}\">unstable</a>",
841 write!(w, "unstable");
843 write!(w, ")</span>");
846 (Some(v), _) if ver != containing_ver => {
849 "<span class=\"since\" title=\"Stable since Rust version {0}\">{0}</span>",
857 fn render_assoc_item(
860 link: AssocItemLink<'_>,
863 render_mode: RenderMode,
868 header: hir::FnHeader,
871 link: AssocItemLink<'_>,
874 render_mode: RenderMode,
876 let name = meth.name.as_ref().unwrap();
877 let href = match link {
878 AssocItemLink::Anchor(Some(ref id)) => Some(format!("#{}", id)),
879 AssocItemLink::Anchor(None) => Some(format!("#{}.{}", meth.type_(), name)),
880 AssocItemLink::GotoSource(did, provided_methods) => {
881 // We're creating a link from an impl-item to the corresponding
882 // trait-item and need to map the anchored type accordingly.
883 let ty = if provided_methods.contains(name) {
889 match (href(did.expect_def_id(), cx), ty) {
890 (Ok(p), ty) => Some(format!("{}#{}.{}", p.0, ty, name)),
891 (Err(HrefError::DocumentationNotBuilt), ItemType::TyMethod) => None,
892 (Err(_), ty) => Some(format!("#{}.{}", ty, name)),
896 let vis = meth.visibility.print_with_space(meth.def_id, cx).to_string();
897 // FIXME: Once https://github.com/rust-lang/rust/issues/67792 is implemented, we can remove
899 let constness = match render_mode {
900 RenderMode::Normal => {
901 print_constness_with_space(&header.constness, meth.const_stability(cx.tcx()))
903 RenderMode::ForDeref { .. } => "",
905 let asyncness = header.asyncness.print_with_space();
906 let unsafety = header.unsafety.print_with_space();
907 let defaultness = print_default_space(meth.is_default());
908 let abi = print_abi_with_space(header.abi).to_string();
910 // NOTE: `{:#}` does not print HTML formatting, `{}` does. So `g.print` can't be reused between the length calculation and `write!`.
911 let generics_len = format!("{:#}", g.print(cx)).len();
912 let mut header_len = "fn ".len()
919 + name.as_str().len()
922 let (indent, indent_str, end_newline) = if parent == ItemType::Trait {
924 let indent_str = " ";
925 render_attributes_in_pre(w, meth, indent_str);
926 (4, indent_str, false)
928 render_attributes_in_code(w, meth);
931 w.reserve(header_len + "<a href=\"\" class=\"fnname\">{".len() + "</a>".len());
934 "{indent}{vis}{constness}{asyncness}{unsafety}{defaultness}{abi}fn <a {href} class=\"fnname\">{name}</a>\
935 {generics}{decl}{notable_traits}{where_clause}",
938 constness = constness,
939 asyncness = asyncness,
941 defaultness = defaultness,
943 // links without a href are valid - https://www.w3schools.com/tags/att_a_href.asp
944 href = href.map(|href| format!("href=\"{}\"", href)).unwrap_or_else(|| "".to_string()),
946 generics = g.print(cx),
947 decl = d.full_print(header_len, indent, header.asyncness, cx),
948 notable_traits = notable_traits_decl(d, cx),
949 where_clause = print_where_clause(g, cx, indent, end_newline),
953 clean::StrippedItem(..) => {}
954 clean::TyMethodItem(ref m) => {
955 method(w, item, m.header, &m.generics, &m.decl, link, parent, cx, render_mode)
957 clean::MethodItem(ref m, _) => {
958 method(w, item, m.header, &m.generics, &m.decl, link, parent, cx, render_mode)
960 clean::AssocConstItem(ref ty, _) => {
961 assoc_const(w, item, ty, link, if parent == ItemType::Trait { " " } else { "" }, cx)
963 clean::AssocTypeItem(ref bounds, ref default) => assoc_type(
969 if parent == ItemType::Trait { " " } else { "" },
972 _ => panic!("render_assoc_item called on non-associated-item"),
976 const ALLOWED_ATTRIBUTES: &[Symbol] =
977 &[sym::export_name, sym::link_section, sym::no_mangle, sym::repr, sym::non_exhaustive];
979 fn attributes(it: &clean::Item) -> Vec<String> {
984 if ALLOWED_ATTRIBUTES.contains(&attr.name_or_empty()) {
985 Some(pprust::attribute_to_string(attr).replace('\n', "").replace(" ", " "))
993 // When an attribute is rendered inside a `<pre>` tag, it is formatted using
994 // a whitespace prefix and newline.
995 fn render_attributes_in_pre(w: &mut Buffer, it: &clean::Item, prefix: &str) {
996 for a in attributes(it) {
997 writeln!(w, "{}{}", prefix, a);
1001 // When an attribute is rendered inside a <code> tag, it is formatted using
1002 // a div to produce a newline after it.
1003 fn render_attributes_in_code(w: &mut Buffer, it: &clean::Item) {
1004 for a in attributes(it) {
1005 write!(w, "<div class=\"code-attribute\">{}</div>", a);
1009 #[derive(Copy, Clone)]
1010 enum AssocItemLink<'a> {
1011 Anchor(Option<&'a str>),
1012 GotoSource(ItemId, &'a FxHashSet<Symbol>),
1015 impl<'a> AssocItemLink<'a> {
1016 fn anchor(&self, id: &'a str) -> Self {
1018 AssocItemLink::Anchor(_) => AssocItemLink::Anchor(Some(id)),
1019 ref other => *other,
1024 fn render_assoc_items(
1027 containing_item: &clean::Item,
1029 what: AssocItemRender<'_>,
1031 let mut derefs = FxHashSet::default();
1033 render_assoc_items_inner(w, cx, containing_item, it, what, &mut derefs)
1036 fn render_assoc_items_inner(
1039 containing_item: &clean::Item,
1041 what: AssocItemRender<'_>,
1042 derefs: &mut FxHashSet<DefId>,
1044 info!("Documenting associated items of {:?}", containing_item.name);
1045 let cache = cx.cache();
1046 let v = match cache.impls.get(&it) {
1050 let (non_trait, traits): (Vec<_>, _) = v.iter().partition(|i| i.inner_impl().trait_.is_none());
1051 if !non_trait.is_empty() {
1052 let mut tmp_buf = Buffer::empty_from(w);
1053 let render_mode = match what {
1054 AssocItemRender::All => {
1056 "<h2 id=\"implementations\" class=\"small-section-header\">\
1057 Implementations<a href=\"#implementations\" class=\"anchor\"></a>\
1062 AssocItemRender::DerefFor { trait_, type_, deref_mut_ } => {
1064 cx.derive_id(small_url_encode(format!("deref-methods-{:#}", type_.print(cx))));
1065 if let Some(def_id) = type_.def_id(cx.cache()) {
1066 cx.deref_id_map.borrow_mut().insert(def_id, id.clone());
1070 "<h2 id=\"{id}\" class=\"small-section-header\">\
1071 <span>Methods from {trait_}<Target = {type_}></span>\
1072 <a href=\"#{id}\" class=\"anchor\"></a>\
1075 trait_ = trait_.print(cx),
1076 type_ = type_.print(cx),
1078 RenderMode::ForDeref { mut_: deref_mut_ }
1081 let mut impls_buf = Buffer::empty_from(w);
1082 for i in &non_trait {
1088 AssocItemLink::Anchor(None),
1092 ImplRenderingParameters {
1093 show_def_docs: true,
1094 is_on_foreign_type: false,
1095 show_default_items: true,
1096 show_non_assoc_items: true,
1097 toggle_open_by_default: true,
1101 if !impls_buf.is_empty() {
1102 w.push_buffer(tmp_buf);
1103 w.push_buffer(impls_buf);
1107 if !traits.is_empty() {
1109 traits.iter().find(|t| t.trait_did() == cx.tcx().lang_items().deref_trait());
1110 if let Some(impl_) = deref_impl {
1112 traits.iter().any(|t| t.trait_did() == cx.tcx().lang_items().deref_mut_trait());
1113 render_deref_methods(w, cx, impl_, containing_item, has_deref_mut, derefs);
1116 // If we were already one level into rendering deref methods, we don't want to render
1117 // anything after recursing into any further deref methods above.
1118 if let AssocItemRender::DerefFor { .. } = what {
1122 let (synthetic, concrete): (Vec<&&Impl>, Vec<&&Impl>) =
1123 traits.iter().partition(|t| t.inner_impl().kind.is_auto());
1124 let (blanket_impl, concrete): (Vec<&&Impl>, _) =
1125 concrete.into_iter().partition(|t| t.inner_impl().kind.is_blanket());
1127 let mut impls = Buffer::empty_from(w);
1128 render_impls(cx, &mut impls, &concrete, containing_item);
1129 let impls = impls.into_inner();
1130 if !impls.is_empty() {
1133 "<h2 id=\"trait-implementations\" class=\"small-section-header\">\
1134 Trait Implementations<a href=\"#trait-implementations\" class=\"anchor\"></a>\
1136 <div id=\"trait-implementations-list\">{}</div>",
1141 if !synthetic.is_empty() {
1143 "<h2 id=\"synthetic-implementations\" class=\"small-section-header\">\
1144 Auto Trait Implementations\
1145 <a href=\"#synthetic-implementations\" class=\"anchor\"></a>\
1147 <div id=\"synthetic-implementations-list\">",
1149 render_impls(cx, w, &synthetic, containing_item);
1150 w.write_str("</div>");
1153 if !blanket_impl.is_empty() {
1155 "<h2 id=\"blanket-implementations\" class=\"small-section-header\">\
1156 Blanket Implementations\
1157 <a href=\"#blanket-implementations\" class=\"anchor\"></a>\
1159 <div id=\"blanket-implementations-list\">",
1161 render_impls(cx, w, &blanket_impl, containing_item);
1162 w.write_str("</div>");
1167 fn render_deref_methods(
1171 container_item: &clean::Item,
1173 derefs: &mut FxHashSet<DefId>,
1175 let cache = cx.cache();
1176 let deref_type = impl_.inner_impl().trait_.as_ref().unwrap();
1177 let (target, real_target) = impl_
1181 .find_map(|item| match *item.kind {
1182 clean::TypedefItem(ref t, true) => Some(match *t {
1183 clean::Typedef { item_type: Some(ref type_), .. } => (type_, &t.type_),
1184 _ => (&t.type_, &t.type_),
1188 .expect("Expected associated type binding");
1189 debug!("Render deref methods for {:#?}, target {:#?}", impl_.inner_impl().for_, target);
1191 AssocItemRender::DerefFor { trait_: deref_type, type_: real_target, deref_mut_: deref_mut };
1192 if let Some(did) = target.def_id(cache) {
1193 if let Some(type_did) = impl_.inner_impl().for_.def_id(cache) {
1194 // `impl Deref<Target = S> for S`
1195 if did == type_did || !derefs.insert(did) {
1196 // Avoid infinite cycles
1200 render_assoc_items_inner(w, cx, container_item, did, what, derefs);
1202 if let Some(prim) = target.primitive_type() {
1203 if let Some(&did) = cache.primitive_locations.get(&prim) {
1204 render_assoc_items_inner(w, cx, container_item, did, what, derefs);
1210 fn should_render_item(item: &clean::Item, deref_mut_: bool, tcx: TyCtxt<'_>) -> bool {
1211 let self_type_opt = match *item.kind {
1212 clean::MethodItem(ref method, _) => method.decl.self_type(),
1213 clean::TyMethodItem(ref method) => method.decl.self_type(),
1217 if let Some(self_ty) = self_type_opt {
1218 let (by_mut_ref, by_box, by_value) = match self_ty {
1219 SelfTy::SelfBorrowed(_, mutability)
1220 | SelfTy::SelfExplicit(clean::BorrowedRef { mutability, .. }) => {
1221 (mutability == Mutability::Mut, false, false)
1223 SelfTy::SelfExplicit(clean::Type::Path { path }) => {
1224 (false, Some(path.def_id()) == tcx.lang_items().owned_box(), false)
1226 SelfTy::SelfValue => (false, false, true),
1227 _ => (false, false, false),
1230 (deref_mut_ || !by_mut_ref) && !by_box && !by_value
1236 fn notable_traits_decl(decl: &clean::FnDecl, cx: &Context<'_>) -> String {
1237 let mut out = Buffer::html();
1239 if let Some((did, ty)) = decl.output.as_return().and_then(|t| Some((t.def_id(cx.cache())?, t)))
1241 if let Some(impls) = cx.cache().impls.get(&did) {
1243 let impl_ = i.inner_impl();
1244 if !impl_.for_.without_borrowed_ref().is_same(ty.without_borrowed_ref(), cx.cache())
1246 // Two different types might have the same did,
1247 // without actually being the same.
1250 if let Some(trait_) = &impl_.trait_ {
1251 let trait_did = trait_.def_id();
1253 if cx.cache().traits.get(&trait_did).map_or(false, |t| t.is_notable) {
1257 "<div class=\"notable\">Notable traits for {}</div>\
1258 <code class=\"content\">",
1259 impl_.for_.print(cx)
1263 //use the "where" class here to make it small
1266 "<span class=\"where fmt-newline\">{}</span>",
1267 impl_.print(false, cx)
1269 for it in &impl_.items {
1270 if let clean::TypedefItem(ref tydef, _) = *it.kind {
1271 out.push_str("<span class=\"where fmt-newline\"> ");
1272 let empty_set = FxHashSet::default();
1274 AssocItemLink::GotoSource(trait_did.into(), &empty_set);
1275 assoc_type(&mut out, it, &[], Some(&tydef.type_), src_link, "", cx);
1276 out.push_str(";</span>");
1285 if !out.is_empty() {
1288 "<span class=\"notable-traits\"><span class=\"notable-traits-tooltip\">ⓘ\
1289 <div class=\"notable-traits-tooltiptext\"><span class=\"docblock\">",
1291 out.push_str("</code></span></div></span></span>");
1297 #[derive(Clone, Copy, Debug)]
1298 struct ImplRenderingParameters {
1299 show_def_docs: bool,
1300 is_on_foreign_type: bool,
1301 show_default_items: bool,
1302 /// Whether or not to show methods.
1303 show_non_assoc_items: bool,
1304 toggle_open_by_default: bool,
1311 parent: &clean::Item,
1312 link: AssocItemLink<'_>,
1313 render_mode: RenderMode,
1314 use_absolute: Option<bool>,
1316 rendering_params: ImplRenderingParameters,
1318 let cache = cx.cache();
1319 let traits = &cache.traits;
1320 let trait_ = i.trait_did().map(|did| &traits[&did]);
1321 let mut close_tags = String::new();
1323 // For trait implementations, the `interesting` output contains all methods that have doc
1324 // comments, and the `boring` output contains all methods that do not. The distinction is
1325 // used to allow hiding the boring methods.
1326 // `containing_item` is used for rendering stability info. If the parent is a trait impl,
1327 // `containing_item` will the grandparent, since trait impls can't have stability attached.
1329 boring: &mut Buffer,
1330 interesting: &mut Buffer,
1333 parent: &clean::Item,
1334 containing_item: &clean::Item,
1335 link: AssocItemLink<'_>,
1336 render_mode: RenderMode,
1337 is_default_item: bool,
1338 trait_: Option<&clean::Trait>,
1339 rendering_params: ImplRenderingParameters,
1341 let item_type = item.type_();
1342 let name = item.name.as_ref().unwrap();
1344 let render_method_item = rendering_params.show_non_assoc_items
1345 && match render_mode {
1346 RenderMode::Normal => true,
1347 RenderMode::ForDeref { mut_: deref_mut_ } => {
1348 should_render_item(item, deref_mut_, cx.tcx())
1352 let in_trait_class = if trait_.is_some() { " trait-impl" } else { "" };
1354 let mut doc_buffer = Buffer::empty_from(boring);
1355 let mut info_buffer = Buffer::empty_from(boring);
1356 let mut short_documented = true;
1358 if render_method_item {
1359 if !is_default_item {
1360 if let Some(t) = trait_ {
1361 // The trait item may have been stripped so we might not
1362 // find any documentation or stability for it.
1363 if let Some(it) = t.items.iter().find(|i| i.name == item.name) {
1364 // We need the stability of the item from the trait
1365 // because impls can't have a stability.
1366 if item.doc_value().is_some() {
1367 document_item_info(&mut info_buffer, cx, it, Some(parent));
1368 document_full(&mut doc_buffer, item, cx, HeadingOffset::H5);
1369 short_documented = false;
1371 // In case the item isn't documented,
1372 // provide short documentation from the trait.
1379 rendering_params.show_def_docs,
1384 document_item_info(&mut info_buffer, cx, item, Some(parent));
1385 if rendering_params.show_def_docs {
1386 document_full(&mut doc_buffer, item, cx, HeadingOffset::H5);
1387 short_documented = false;
1397 rendering_params.show_def_docs,
1401 let w = if short_documented && trait_.is_some() { interesting } else { boring };
1403 let toggled = !doc_buffer.is_empty();
1405 let method_toggle_class =
1406 if item_type == ItemType::Method { " method-toggle" } else { "" };
1407 write!(w, "<details class=\"rustdoc-toggle{}\" open><summary>", method_toggle_class);
1410 clean::MethodItem(..) | clean::TyMethodItem(_) => {
1411 // Only render when the method is not static or we allow static methods
1412 if render_method_item {
1413 let id = cx.derive_id(format!("{}.{}", item_type, name));
1414 let source_id = trait_
1415 .and_then(|trait_| {
1416 trait_.items.iter().find(|item| {
1417 item.name.map(|n| n.as_str().eq(name.as_str())).unwrap_or(false)
1420 .map(|item| format!("{}.{}", item.type_(), name));
1423 "<div id=\"{}\" class=\"{}{} has-srclink\">",
1424 id, item_type, in_trait_class,
1426 render_rightside(w, cx, item, containing_item, render_mode);
1427 write!(w, "<a href=\"#{}\" class=\"anchor\"></a>", id);
1428 w.write_str("<h4 class=\"code-header\">");
1432 link.anchor(source_id.as_ref().unwrap_or(&id)),
1437 w.write_str("</h4>");
1438 w.write_str("</div>");
1441 clean::TypedefItem(ref tydef, _) => {
1442 let source_id = format!("{}.{}", ItemType::AssocType, name);
1443 let id = cx.derive_id(source_id.clone());
1446 "<div id=\"{}\" class=\"{}{} has-srclink\">",
1447 id, item_type, in_trait_class
1449 write!(w, "<a href=\"#{}\" class=\"anchor\"></a>", id);
1450 w.write_str("<h4 class=\"code-header\">");
1456 link.anchor(if trait_.is_some() { &source_id } else { &id }),
1460 w.write_str("</h4>");
1461 w.write_str("</div>");
1463 clean::AssocConstItem(ref ty, _) => {
1464 let source_id = format!("{}.{}", item_type, name);
1465 let id = cx.derive_id(source_id.clone());
1468 "<div id=\"{}\" class=\"{}{} has-srclink\">",
1469 id, item_type, in_trait_class
1471 render_rightside(w, cx, item, containing_item, render_mode);
1472 write!(w, "<a href=\"#{}\" class=\"anchor\"></a>", id);
1473 w.write_str("<h4 class=\"code-header\">");
1478 link.anchor(if trait_.is_some() { &source_id } else { &id }),
1482 w.write_str("</h4>");
1483 w.write_str("</div>");
1485 clean::AssocTypeItem(ref bounds, ref default) => {
1486 let source_id = format!("{}.{}", item_type, name);
1487 let id = cx.derive_id(source_id.clone());
1488 write!(w, "<div id=\"{}\" class=\"{}{}\">", id, item_type, in_trait_class,);
1489 write!(w, "<a href=\"#{}\" class=\"anchor\"></a>", id);
1490 w.write_str("<h4 class=\"code-header\">");
1496 link.anchor(if trait_.is_some() { &source_id } else { &id }),
1500 w.write_str("</h4>");
1501 w.write_str("</div>");
1503 clean::StrippedItem(..) => return,
1504 _ => panic!("can't make docs for trait item with name {:?}", item.name),
1507 w.push_buffer(info_buffer);
1509 w.write_str("</summary>");
1510 w.push_buffer(doc_buffer);
1511 w.push_str("</details>");
1515 let mut impl_items = Buffer::empty_from(w);
1516 let mut default_impl_items = Buffer::empty_from(w);
1518 for trait_item in &i.inner_impl().items {
1520 &mut default_impl_items,
1524 if trait_.is_some() { &i.impl_item } else { parent },
1529 trait_.map(|t| &t.trait_),
1534 fn render_default_items(
1535 boring: &mut Buffer,
1536 interesting: &mut Buffer,
1540 parent: &clean::Item,
1541 containing_item: &clean::Item,
1542 render_mode: RenderMode,
1543 rendering_params: ImplRenderingParameters,
1545 for trait_item in &t.items {
1546 let n = trait_item.name;
1547 if i.items.iter().any(|m| m.name == n) {
1550 let did = i.trait_.as_ref().unwrap().def_id();
1551 let provided_methods = i.provided_trait_methods(cx.tcx());
1552 let assoc_link = AssocItemLink::GotoSource(did.into(), &provided_methods);
1570 // If we've implemented a trait, then also emit documentation for all
1571 // default items which weren't overridden in the implementation block.
1572 // We don't emit documentation for default items if they appear in the
1573 // Implementations on Foreign Types or Implementors sections.
1574 if rendering_params.show_default_items {
1575 if let Some(t) = trait_ {
1576 render_default_items(
1577 &mut default_impl_items,
1589 if render_mode == RenderMode::Normal {
1590 let toggled = !(impl_items.is_empty() && default_impl_items.is_empty());
1592 close_tags.insert_str(0, "</details>");
1595 "<details class=\"rustdoc-toggle implementors-toggle\"{}>",
1596 if rendering_params.toggle_open_by_default { " open" } else { "" }
1598 write!(w, "<summary>")
1600 render_impl_summary(
1606 rendering_params.show_def_docs,
1608 rendering_params.is_on_foreign_type,
1612 write!(w, "</summary>")
1615 if let Some(ref dox) = i.impl_item.collapsed_doc_value() {
1616 let mut ids = cx.id_map.borrow_mut();
1619 "<div class=\"docblock\">{}</div>",
1622 links: &i.impl_item.links(cx),
1624 error_codes: cx.shared.codes,
1625 edition: cx.shared.edition(),
1626 playground: &cx.shared.playground,
1627 heading_offset: HeadingOffset::H4
1633 if !default_impl_items.is_empty() || !impl_items.is_empty() {
1634 w.write_str("<div class=\"impl-items\">");
1635 w.push_buffer(default_impl_items);
1636 w.push_buffer(impl_items);
1637 close_tags.insert_str(0, "</div>");
1639 w.write_str(&close_tags);
1642 // Render the items that appear on the right side of methods, impls, and
1643 // associated types. For example "1.0.0 (const: 1.39.0) [src]".
1644 fn render_rightside(
1648 containing_item: &clean::Item,
1649 render_mode: RenderMode,
1653 // FIXME: Once https://github.com/rust-lang/rust/issues/67792 is implemented, we can remove
1655 let (const_stability, const_stable_since) = match render_mode {
1656 RenderMode::Normal => (item.const_stability(tcx), containing_item.const_stable_since(tcx)),
1657 RenderMode::ForDeref { .. } => (None, None),
1660 write!(w, "<div class=\"rightside\">");
1661 render_stability_since_raw(
1663 item.stable_since(tcx),
1665 containing_item.stable_since(tcx),
1669 write_srclink(cx, item, w);
1670 w.write_str("</div>");
1673 pub(crate) fn render_impl_summary(
1677 parent: &clean::Item,
1678 containing_item: &clean::Item,
1679 show_def_docs: bool,
1680 use_absolute: Option<bool>,
1681 is_on_foreign_type: bool,
1682 // This argument is used to reference same type with different paths to avoid duplication
1683 // in documentation pages for trait with automatic implementations like "Send" and "Sync".
1686 let id = cx.derive_id(match i.inner_impl().trait_ {
1688 if is_on_foreign_type {
1689 get_id_for_impl_on_foreign_type(&i.inner_impl().for_, t, cx)
1691 format!("impl-{}", small_url_encode(format!("{:#}", t.print(cx))))
1694 None => "impl".to_string(),
1696 let aliases = if aliases.is_empty() {
1699 format!(" data-aliases=\"{}\"", aliases.join(","))
1701 write!(w, "<div id=\"{}\" class=\"impl has-srclink\"{}>", id, aliases);
1702 render_rightside(w, cx, &i.impl_item, containing_item, RenderMode::Normal);
1703 write!(w, "<a href=\"#{}\" class=\"anchor\"></a>", id);
1704 write!(w, "<h3 class=\"code-header in-band\">");
1706 if let Some(use_absolute) = use_absolute {
1707 write!(w, "{}", i.inner_impl().print(use_absolute, cx));
1709 for it in &i.inner_impl().items {
1710 if let clean::TypedefItem(ref tydef, _) = *it.kind {
1711 w.write_str("<span class=\"where fmt-newline\"> ");
1712 assoc_type(w, it, &[], Some(&tydef.type_), AssocItemLink::Anchor(None), "", cx);
1713 w.write_str(";</span>");
1718 write!(w, "{}", i.inner_impl().print(false, cx));
1722 let is_trait = i.inner_impl().trait_.is_some();
1724 if let Some(portability) = portability(&i.impl_item, Some(parent)) {
1725 write!(w, "<div class=\"item-info\">{}</div>", portability);
1729 w.write_str("</div>");
1732 fn print_sidebar(cx: &Context<'_>, it: &clean::Item, buffer: &mut Buffer) {
1733 let parentlen = cx.current.len() - if it.is_mod() { 1 } else { 0 };
1737 || it.is_primitive()
1745 "<h2 class=\"location\">{}{}</h2>",
1747 clean::StructItem(..) => "Struct ",
1748 clean::TraitItem(..) => "Trait ",
1749 clean::PrimitiveItem(..) => "Primitive Type ",
1750 clean::UnionItem(..) => "Union ",
1751 clean::EnumItem(..) => "Enum ",
1752 clean::TypedefItem(..) => "Type Definition ",
1753 clean::ForeignTypeItem => "Foreign Type ",
1754 clean::ModuleItem(..) =>
1762 it.name.as_ref().unwrap()
1767 if let Some(ref version) = cx.cache().crate_version {
1770 "<div class=\"block version\">\
1771 <div class=\"narrow-helper\"></div>\
1779 buffer.write_str("<div class=\"sidebar-elems\">");
1783 "<a id=\"all-types\" href=\"all.html\"><p>See all {}'s items</p></a>",
1784 it.name.as_ref().expect("crates always have a name"),
1789 clean::StructItem(ref s) => sidebar_struct(cx, buffer, it, s),
1790 clean::TraitItem(ref t) => sidebar_trait(cx, buffer, it, t),
1791 clean::PrimitiveItem(_) => sidebar_primitive(cx, buffer, it),
1792 clean::UnionItem(ref u) => sidebar_union(cx, buffer, it, u),
1793 clean::EnumItem(ref e) => sidebar_enum(cx, buffer, it, e),
1794 clean::TypedefItem(_, _) => sidebar_typedef(cx, buffer, it),
1795 clean::ModuleItem(ref m) => sidebar_module(buffer, &m.items),
1796 clean::ForeignTypeItem => sidebar_foreign_type(cx, buffer, it),
1800 // The sidebar is designed to display sibling functions, modules and
1801 // other miscellaneous information. since there are lots of sibling
1802 // items (and that causes quadratic growth in large modules),
1803 // we refactor common parts into a shared JavaScript file per module.
1804 // still, we don't move everything into JS because we want to preserve
1805 // as much HTML as possible in order to allow non-JS-enabled browsers
1806 // to navigate the documentation (though slightly inefficiently).
1809 buffer.write_str("<h2 class=\"location\">Other items in<br>");
1810 for (i, name) in cx.current.iter().take(parentlen).enumerate() {
1812 buffer.write_str("::<wbr>");
1816 "<a href=\"{}index.html\">{}</a>",
1817 &cx.root_path()[..(cx.current.len() - i - 1) * 3],
1821 buffer.write_str("</h2>");
1824 // Sidebar refers to the enclosing module, not this module.
1825 let relpath = if it.is_mod() && parentlen != 0 { "./" } else { "" };
1828 "<div id=\"sidebar-vars\" data-name=\"{name}\" data-ty=\"{ty}\" data-relpath=\"{path}\">\
1830 name = it.name.unwrap_or(kw::Empty),
1834 write!(buffer, "<script defer src=\"{}sidebar-items.js\"></script>", relpath);
1835 // Closes sidebar-elems div.
1836 buffer.write_str("</div>");
1839 fn get_next_url(used_links: &mut FxHashSet<String>, url: String) -> String {
1840 if used_links.insert(url.clone()) {
1844 while !used_links.insert(format!("{}-{}", url, add)) {
1847 format!("{}-{}", url, add)
1850 struct SidebarLink {
1855 impl fmt::Display for SidebarLink {
1856 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1857 write!(f, "<a href=\"#{}\">{}</a>", self.url, self.name)
1861 impl PartialEq for SidebarLink {
1862 fn eq(&self, other: &Self) -> bool {
1863 self.url == other.url
1867 impl Eq for SidebarLink {}
1869 impl PartialOrd for SidebarLink {
1870 fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
1871 Some(self.cmp(other))
1875 impl Ord for SidebarLink {
1876 fn cmp(&self, other: &Self) -> std::cmp::Ordering {
1877 self.url.cmp(&other.url)
1884 used_links: &mut FxHashSet<String>,
1887 ) -> Vec<SidebarLink> {
1890 .filter_map(|item| match item.name {
1891 Some(name) if !name.is_empty() && item.is_method() => {
1892 if !for_deref || should_render_item(item, deref_mut, tcx) {
1895 url: get_next_url(used_links, format!("method.{}", name)),
1903 .collect::<Vec<_>>()
1906 fn get_associated_constants(
1908 used_links: &mut FxHashSet<String>,
1909 ) -> Vec<SidebarLink> {
1912 .filter_map(|item| match item.name {
1913 Some(name) if !name.is_empty() && item.is_associated_const() => Some(SidebarLink {
1915 url: get_next_url(used_links, format!("associatedconstant.{}", name)),
1919 .collect::<Vec<_>>()
1922 // The point is to url encode any potential character from a type with genericity.
1923 fn small_url_encode(s: String) -> String {
1924 let mut st = String::new();
1925 let mut last_match = 0;
1926 for (idx, c) in s.char_indices() {
1927 let escaped = match c {
1943 st += &s[last_match..idx];
1945 // NOTE: we only expect single byte characters here - which is fine as long as we
1946 // only match single byte characters
1947 last_match = idx + 1;
1950 if last_match != 0 {
1951 st += &s[last_match..];
1958 fn sidebar_assoc_items(cx: &Context<'_>, out: &mut Buffer, it: &clean::Item) {
1959 let did = it.def_id.expect_def_id();
1960 let cache = cx.cache();
1961 if let Some(v) = cache.impls.get(&did) {
1962 let mut used_links = FxHashSet::default();
1965 let used_links_bor = &mut used_links;
1966 let mut assoc_consts = v
1968 .flat_map(|i| get_associated_constants(i.inner_impl(), used_links_bor))
1969 .collect::<Vec<_>>();
1970 if !assoc_consts.is_empty() {
1971 // We want links' order to be reproducible so we don't use unstable sort.
1972 assoc_consts.sort();
1975 "<h3 class=\"sidebar-title\">\
1976 <a href=\"#implementations\">Associated Constants</a>\
1978 <div class=\"sidebar-links\">",
1980 for line in assoc_consts {
1981 write!(out, "{}", line);
1983 out.push_str("</div>");
1987 .filter(|i| i.inner_impl().trait_.is_none())
1988 .flat_map(|i| get_methods(i.inner_impl(), false, used_links_bor, false, cx.tcx()))
1989 .collect::<Vec<_>>();
1990 if !methods.is_empty() {
1991 // We want links' order to be reproducible so we don't use unstable sort.
1995 "<h3 class=\"sidebar-title\"><a href=\"#implementations\">Methods</a></h3>\
1996 <div class=\"sidebar-links\">",
1998 for line in methods {
1999 write!(out, "{}", line);
2001 out.push_str("</div>");
2005 if v.iter().any(|i| i.inner_impl().trait_.is_some()) {
2006 if let Some(impl_) =
2007 v.iter().find(|i| i.trait_did() == cx.tcx().lang_items().deref_trait())
2009 let mut derefs = FxHashSet::default();
2011 sidebar_deref_methods(cx, out, impl_, v, &mut derefs);
2014 let format_impls = |impls: Vec<&Impl>| {
2015 let mut links = FxHashSet::default();
2020 if let Some(ref i) = it.inner_impl().trait_ {
2021 let i_display = format!("{:#}", i.print(cx));
2022 let out = Escape(&i_display);
2023 let encoded = small_url_encode(format!("{:#}", i.print(cx)));
2024 let prefix = match it.inner_impl().polarity {
2025 ty::ImplPolarity::Positive | ty::ImplPolarity::Reservation => "",
2026 ty::ImplPolarity::Negative => "!",
2029 format!("<a href=\"#impl-{}\">{}{}</a>", encoded, prefix, out);
2030 if links.insert(generated.clone()) { Some(generated) } else { None }
2035 .collect::<Vec<String>>();
2040 let write_sidebar_links = |out: &mut Buffer, links: Vec<String>| {
2041 out.push_str("<div class=\"sidebar-links\">");
2043 out.push_str(&link);
2045 out.push_str("</div>");
2048 let (synthetic, concrete): (Vec<&Impl>, Vec<&Impl>) =
2049 v.iter().partition::<Vec<_>, _>(|i| i.inner_impl().kind.is_auto());
2050 let (blanket_impl, concrete): (Vec<&Impl>, Vec<&Impl>) =
2051 concrete.into_iter().partition::<Vec<_>, _>(|i| i.inner_impl().kind.is_blanket());
2053 let concrete_format = format_impls(concrete);
2054 let synthetic_format = format_impls(synthetic);
2055 let blanket_format = format_impls(blanket_impl);
2057 if !concrete_format.is_empty() {
2059 "<h3 class=\"sidebar-title\"><a href=\"#trait-implementations\">\
2060 Trait Implementations</a></h3>",
2062 write_sidebar_links(out, concrete_format);
2065 if !synthetic_format.is_empty() {
2067 "<h3 class=\"sidebar-title\"><a href=\"#synthetic-implementations\">\
2068 Auto Trait Implementations</a></h3>",
2070 write_sidebar_links(out, synthetic_format);
2073 if !blanket_format.is_empty() {
2075 "<h3 class=\"sidebar-title\"><a href=\"#blanket-implementations\">\
2076 Blanket Implementations</a></h3>",
2078 write_sidebar_links(out, blanket_format);
2084 fn sidebar_deref_methods(
2089 derefs: &mut FxHashSet<DefId>,
2093 debug!("found Deref: {:?}", impl_);
2094 if let Some((target, real_target)) =
2095 impl_.inner_impl().items.iter().find_map(|item| match *item.kind {
2096 clean::TypedefItem(ref t, true) => Some(match *t {
2097 clean::Typedef { item_type: Some(ref type_), .. } => (type_, &t.type_),
2098 _ => (&t.type_, &t.type_),
2103 debug!("found target, real_target: {:?} {:?}", target, real_target);
2104 if let Some(did) = target.def_id(c) {
2105 if let Some(type_did) = impl_.inner_impl().for_.def_id(c) {
2106 // `impl Deref<Target = S> for S`
2107 if did == type_did || !derefs.insert(did) {
2108 // Avoid infinite cycles
2113 let deref_mut = v.iter().any(|i| i.trait_did() == cx.tcx().lang_items().deref_mut_trait());
2114 let inner_impl = target
2117 target.primitive_type().and_then(|prim| c.primitive_locations.get(&prim).cloned())
2119 .and_then(|did| c.impls.get(&did));
2120 if let Some(impls) = inner_impl {
2121 debug!("found inner_impl: {:?}", impls);
2122 let mut used_links = FxHashSet::default();
2125 .filter(|i| i.inner_impl().trait_.is_none())
2127 get_methods(i.inner_impl(), true, &mut used_links, deref_mut, cx.tcx())
2129 .collect::<Vec<_>>();
2130 if !ret.is_empty() {
2132 let id = if let Some(target_def_id) = real_target.def_id(c) {
2133 map = cx.deref_id_map.borrow();
2134 map.get(&target_def_id).expect("Deref section without derived id")
2140 "<h3 class=\"sidebar-title\"><a href=\"#{}\">Methods from {}<Target={}></a></h3>",
2142 Escape(&format!("{:#}", impl_.inner_impl().trait_.as_ref().unwrap().print(cx))),
2143 Escape(&format!("{:#}", real_target.print(cx))),
2145 // We want links' order to be reproducible so we don't use unstable sort.
2147 out.push_str("<div class=\"sidebar-links\">");
2149 write!(out, "{}", link);
2151 out.push_str("</div>");
2155 // Recurse into any further impls that might exist for `target`
2156 if let Some(target_did) = target.def_id(c) {
2157 if let Some(target_impls) = c.impls.get(&target_did) {
2158 if let Some(target_deref_impl) = target_impls.iter().find(|i| {
2162 .map(|t| Some(t.def_id()) == cx.tcx().lang_items().deref_trait())
2165 sidebar_deref_methods(cx, out, target_deref_impl, target_impls, derefs);
2172 fn sidebar_struct(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, s: &clean::Struct) {
2173 let mut sidebar = Buffer::new();
2174 let fields = get_struct_fields_name(&s.fields);
2176 if !fields.is_empty() {
2177 if let CtorKind::Fictive = s.struct_type {
2179 "<h3 class=\"sidebar-title\"><a href=\"#fields\">Fields</a></h3>\
2180 <div class=\"sidebar-links\">",
2183 for field in fields {
2184 sidebar.push_str(&field);
2187 sidebar.push_str("</div>");
2188 } else if let CtorKind::Fn = s.struct_type {
2190 .push_str("<h3 class=\"sidebar-title\"><a href=\"#fields\">Tuple Fields</a></h3>");
2194 sidebar_assoc_items(cx, &mut sidebar, it);
2196 if !sidebar.is_empty() {
2197 write!(buf, "<div class=\"block items\">{}</div>", sidebar.into_inner());
2201 fn get_id_for_impl_on_foreign_type(
2203 trait_: &clean::Path,
2206 small_url_encode(format!("impl-{:#}-for-{:#}", trait_.print(cx), for_.print(cx)))
2209 fn extract_for_impl_name(item: &clean::Item, cx: &Context<'_>) -> Option<(String, String)> {
2211 clean::ItemKind::ImplItem(ref i) => {
2212 i.trait_.as_ref().map(|trait_| {
2213 // Alternative format produces no URLs,
2214 // so this parameter does nothing.
2216 format!("{:#}", i.for_.print(cx)),
2217 get_id_for_impl_on_foreign_type(&i.for_, trait_, cx),
2225 fn sidebar_trait(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, t: &clean::Trait) {
2226 buf.write_str("<div class=\"block items\">");
2228 fn print_sidebar_section(
2230 items: &[clean::Item],
2232 filter: impl Fn(&clean::Item) -> bool,
2233 write: impl Fn(&mut Buffer, &str),
2236 let mut items = items
2238 .filter_map(|m| match m.name {
2239 Some(ref name) if filter(m) => Some(name.as_str()),
2242 .collect::<Vec<_>>();
2244 if !items.is_empty() {
2245 items.sort_unstable();
2246 out.push_str(before);
2247 for item in items.into_iter() {
2250 out.push_str(after);
2254 print_sidebar_section(
2257 "<h3 class=\"sidebar-title\"><a href=\"#associated-types\">\
2258 Associated Types</a></h3><div class=\"sidebar-links\">",
2259 |m| m.is_associated_type(),
2260 |out, sym| write!(out, "<a href=\"#associatedtype.{0}\">{0}</a>", sym),
2264 print_sidebar_section(
2267 "<h3 class=\"sidebar-title\"><a href=\"#associated-const\">\
2268 Associated Constants</a></h3><div class=\"sidebar-links\">",
2269 |m| m.is_associated_const(),
2270 |out, sym| write!(out, "<a href=\"#associatedconstant.{0}\">{0}</a>", sym),
2274 print_sidebar_section(
2277 "<h3 class=\"sidebar-title\"><a href=\"#required-methods\">\
2278 Required Methods</a></h3><div class=\"sidebar-links\">",
2279 |m| m.is_ty_method(),
2280 |out, sym| write!(out, "<a href=\"#tymethod.{0}\">{0}</a>", sym),
2284 print_sidebar_section(
2287 "<h3 class=\"sidebar-title\"><a href=\"#provided-methods\">\
2288 Provided Methods</a></h3><div class=\"sidebar-links\">",
2290 |out, sym| write!(out, "<a href=\"#method.{0}\">{0}</a>", sym),
2294 let cache = cx.cache();
2295 if let Some(implementors) = cache.implementors.get(&it.def_id.expect_def_id()) {
2296 let mut res = implementors
2299 i.inner_impl().for_.def_id(cache).map_or(false, |d| !cache.paths.contains_key(&d))
2301 .filter_map(|i| extract_for_impl_name(&i.impl_item, cx))
2302 .collect::<Vec<_>>();
2304 if !res.is_empty() {
2307 "<h3 class=\"sidebar-title\"><a href=\"#foreign-impls\">\
2308 Implementations on Foreign Types</a></h3>\
2309 <div class=\"sidebar-links\">",
2311 for (name, id) in res.into_iter() {
2312 write!(buf, "<a href=\"#{}\">{}</a>", id, Escape(&name));
2314 buf.push_str("</div>");
2318 sidebar_assoc_items(cx, buf, it);
2320 buf.push_str("<h3 class=\"sidebar-title\"><a href=\"#implementors\">Implementors</a></h3>");
2323 "<h3 class=\"sidebar-title\"><a \
2324 href=\"#synthetic-implementors\">Auto Implementors</a></h3>",
2328 buf.push_str("</div>")
2331 fn sidebar_primitive(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item) {
2332 let mut sidebar = Buffer::new();
2333 sidebar_assoc_items(cx, &mut sidebar, it);
2335 if !sidebar.is_empty() {
2336 write!(buf, "<div class=\"block items\">{}</div>", sidebar.into_inner());
2340 fn sidebar_typedef(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item) {
2341 let mut sidebar = Buffer::new();
2342 sidebar_assoc_items(cx, &mut sidebar, it);
2344 if !sidebar.is_empty() {
2345 write!(buf, "<div class=\"block items\">{}</div>", sidebar.into_inner());
2349 fn get_struct_fields_name(fields: &[clean::Item]) -> Vec<String> {
2350 let mut fields = fields
2352 .filter(|f| matches!(*f.kind, clean::StructFieldItem(..)))
2354 f.name.map(|name| format!("<a href=\"#structfield.{name}\">{name}</a>", name = name))
2356 .collect::<Vec<_>>();
2361 fn sidebar_union(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, u: &clean::Union) {
2362 let mut sidebar = Buffer::new();
2363 let fields = get_struct_fields_name(&u.fields);
2365 if !fields.is_empty() {
2367 "<h3 class=\"sidebar-title\"><a href=\"#fields\">Fields</a></h3>\
2368 <div class=\"sidebar-links\">",
2371 for field in fields {
2372 sidebar.push_str(&field);
2375 sidebar.push_str("</div>");
2378 sidebar_assoc_items(cx, &mut sidebar, it);
2380 if !sidebar.is_empty() {
2381 write!(buf, "<div class=\"block items\">{}</div>", sidebar.into_inner());
2385 fn sidebar_enum(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, e: &clean::Enum) {
2386 let mut sidebar = Buffer::new();
2388 let mut variants = e
2394 .map(|name| format!("<a href=\"#variant.{name}\">{name}</a>", name = name))
2396 .collect::<Vec<_>>();
2397 if !variants.is_empty() {
2398 variants.sort_unstable();
2399 sidebar.push_str(&format!(
2400 "<h3 class=\"sidebar-title\"><a href=\"#variants\">Variants</a></h3>\
2401 <div class=\"sidebar-links\">{}</div>",
2406 sidebar_assoc_items(cx, &mut sidebar, it);
2408 if !sidebar.is_empty() {
2409 write!(buf, "<div class=\"block items\">{}</div>", sidebar.into_inner());
2413 fn item_ty_to_strs(ty: ItemType) -> (&'static str, &'static str) {
2415 ItemType::ExternCrate | ItemType::Import => ("reexports", "Re-exports"),
2416 ItemType::Module => ("modules", "Modules"),
2417 ItemType::Struct => ("structs", "Structs"),
2418 ItemType::Union => ("unions", "Unions"),
2419 ItemType::Enum => ("enums", "Enums"),
2420 ItemType::Function => ("functions", "Functions"),
2421 ItemType::Typedef => ("types", "Type Definitions"),
2422 ItemType::Static => ("statics", "Statics"),
2423 ItemType::Constant => ("constants", "Constants"),
2424 ItemType::Trait => ("traits", "Traits"),
2425 ItemType::Impl => ("impls", "Implementations"),
2426 ItemType::TyMethod => ("tymethods", "Type Methods"),
2427 ItemType::Method => ("methods", "Methods"),
2428 ItemType::StructField => ("fields", "Struct Fields"),
2429 ItemType::Variant => ("variants", "Variants"),
2430 ItemType::Macro => ("macros", "Macros"),
2431 ItemType::Primitive => ("primitives", "Primitive Types"),
2432 ItemType::AssocType => ("associated-types", "Associated Types"),
2433 ItemType::AssocConst => ("associated-consts", "Associated Constants"),
2434 ItemType::ForeignType => ("foreign-types", "Foreign Types"),
2435 ItemType::Keyword => ("keywords", "Keywords"),
2436 ItemType::OpaqueTy => ("opaque-types", "Opaque Types"),
2437 ItemType::ProcAttribute => ("attributes", "Attribute Macros"),
2438 ItemType::ProcDerive => ("derives", "Derive Macros"),
2439 ItemType::TraitAlias => ("trait-aliases", "Trait aliases"),
2440 ItemType::Generic => unreachable!(),
2444 fn sidebar_module(buf: &mut Buffer, items: &[clean::Item]) {
2445 let mut sidebar = String::new();
2447 // Re-exports are handled a bit differently because they can be extern crates or imports.
2448 if items.iter().any(|it| {
2450 && (it.type_() == ItemType::ExternCrate
2451 || (it.type_() == ItemType::Import && !it.is_stripped()))
2453 let (id, name) = item_ty_to_strs(ItemType::Import);
2454 sidebar.push_str(&format!("<li><a href=\"#{}\">{}</a></li>", id, name));
2457 // ordering taken from item_module, reorder, where it prioritized elements in a certain order
2458 // to print its headings
2460 ItemType::Primitive,
2474 ItemType::StructField,
2476 ItemType::AssocType,
2477 ItemType::AssocConst,
2478 ItemType::ForeignType,
2481 if items.iter().any(|it| !it.is_stripped() && it.type_() == myty && it.name.is_some()) {
2482 let (id, name) = item_ty_to_strs(myty);
2483 sidebar.push_str(&format!("<li><a href=\"#{}\">{}</a></li>", id, name));
2487 if !sidebar.is_empty() {
2488 write!(buf, "<div class=\"block items\"><ul>{}</ul></div>", sidebar);
2492 fn sidebar_foreign_type(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item) {
2493 let mut sidebar = Buffer::new();
2494 sidebar_assoc_items(cx, &mut sidebar, it);
2496 if !sidebar.is_empty() {
2497 write!(buf, "<div class=\"block items\">{}</div>", sidebar.into_inner());
2501 crate const BASIC_KEYWORDS: &str = "rust, rustlang, rust-lang";
2503 /// Returns a list of all paths used in the type.
2504 /// This is used to help deduplicate imported impls
2505 /// for reexported types. If any of the contained
2506 /// types are re-exported, we don't use the corresponding
2507 /// entry from the js file, as inlining will have already
2508 /// picked up the impl
2509 fn collect_paths_for_type(first_ty: clean::Type, cache: &Cache) -> Vec<String> {
2510 let mut out = Vec::new();
2511 let mut visited = FxHashSet::default();
2512 let mut work = VecDeque::new();
2514 let mut process_path = |did: DefId| {
2515 let get_extern = || cache.external_paths.get(&did).map(|s| s.0.clone());
2516 let fqp = cache.exact_paths.get(&did).cloned().or_else(get_extern);
2518 if let Some(path) = fqp {
2519 out.push(path.join("::"));
2523 work.push_back(first_ty);
2525 while let Some(ty) = work.pop_front() {
2526 if !visited.insert(ty.clone()) {
2531 clean::Type::Path { path } => process_path(path.def_id()),
2532 clean::Type::Tuple(tys) => {
2533 work.extend(tys.into_iter());
2535 clean::Type::Slice(ty) => {
2536 work.push_back(*ty);
2538 clean::Type::Array(ty, _) => {
2539 work.push_back(*ty);
2541 clean::Type::RawPointer(_, ty) => {
2542 work.push_back(*ty);
2544 clean::Type::BorrowedRef { type_, .. } => {
2545 work.push_back(*type_);
2547 clean::Type::QPath { self_type, trait_, .. } => {
2548 work.push_back(*self_type);
2549 process_path(trait_.def_id());
2557 const MAX_FULL_EXAMPLES: usize = 5;
2558 const NUM_VISIBLE_LINES: usize = 10;
2560 /// Generates the HTML for example call locations generated via the --scrape-examples flag.
2561 fn render_call_locations(w: &mut Buffer, cx: &Context<'_>, item: &clean::Item) {
2563 let def_id = item.def_id.expect_def_id();
2564 let key = tcx.def_path_hash(def_id);
2565 let call_locations = match cx.shared.call_locations.get(&key) {
2566 Some(call_locations) => call_locations,
2572 // Generate a unique ID so users can link to this section for a given method
2573 let id = cx.id_map.borrow_mut().derive("scraped-examples");
2576 "<div class=\"docblock scraped-example-list\">\
2578 <h5 id=\"{id}\" class=\"section-header\">\
2579 <a href=\"#{id}\">Examples found in repository</a>\
2584 // Create a URL to a particular location in a reverse-dependency's source file
2585 let link_to_loc = |call_data: &CallData, loc: &CallLocation| -> (String, String) {
2586 let (line_lo, line_hi) = loc.call_expr.line_span;
2587 let (anchor, title) = if line_lo == line_hi {
2588 ((line_lo + 1).to_string(), format!("line {}", line_lo + 1))
2591 format!("{}-{}", line_lo + 1, line_hi + 1),
2592 format!("lines {}-{}", line_lo + 1, line_hi + 1),
2595 let url = format!("{}{}#{}", cx.root_path(), call_data.url, anchor);
2599 // Generate the HTML for a single example, being the title and code block
2600 let write_example = |w: &mut Buffer, (path, call_data): (&PathBuf, &CallData)| -> bool {
2601 let contents = match fs::read_to_string(&path) {
2602 Ok(contents) => contents,
2604 let span = item.span(tcx).inner();
2606 .span_err(span, &format!("failed to read file {}: {}", path.display(), err));
2611 // To reduce file sizes, we only want to embed the source code needed to understand the example, not
2612 // the entire file. So we find the smallest byte range that covers all items enclosing examples.
2613 assert!(!call_data.locations.is_empty());
2615 call_data.locations.iter().min_by_key(|loc| loc.enclosing_item.byte_span.0).unwrap();
2616 let byte_min = min_loc.enclosing_item.byte_span.0;
2617 let line_min = min_loc.enclosing_item.line_span.0;
2619 call_data.locations.iter().max_by_key(|loc| loc.enclosing_item.byte_span.1).unwrap();
2620 let byte_max = max_loc.enclosing_item.byte_span.1;
2621 let line_max = max_loc.enclosing_item.line_span.1;
2623 // The output code is limited to that byte range.
2624 let contents_subset = &contents[(byte_min as usize)..(byte_max as usize)];
2626 // The call locations need to be updated to reflect that the size of the program has changed.
2627 // Specifically, the ranges are all subtracted by `byte_min` since that's the new zero point.
2628 let (mut byte_ranges, line_ranges): (Vec<_>, Vec<_>) = call_data
2632 let (byte_lo, byte_hi) = loc.call_expr.byte_span;
2633 let (line_lo, line_hi) = loc.call_expr.line_span;
2634 let byte_range = (byte_lo - byte_min, byte_hi - byte_min);
2635 let line_range = (line_lo - line_min, line_hi - line_min);
2636 let (line_url, line_title) = link_to_loc(call_data, loc);
2638 (byte_range, (line_range, line_url, line_title))
2642 let (_, init_url, init_title) = &line_ranges[0];
2643 let needs_expansion = line_max - line_min > NUM_VISIBLE_LINES;
2644 let locations_encoded = serde_json::to_string(&line_ranges).unwrap();
2648 "<div class=\"scraped-example {expanded_cls}\" data-locs=\"{locations}\">\
2649 <div class=\"scraped-example-title\">\
2650 {name} (<a href=\"{url}\">{title}</a>)\
2652 <div class=\"code-wrapper\">",
2653 expanded_cls = if needs_expansion { "" } else { "expanded" },
2654 name = call_data.display_name,
2657 // The locations are encoded as a data attribute, so they can be read
2658 // later by the JS for interactions.
2659 locations = Escape(&locations_encoded)
2662 if line_ranges.len() > 1 {
2663 write!(w, r#"<span class="prev">≺</span> <span class="next">≻</span>"#);
2666 if needs_expansion {
2667 write!(w, r#"<span class="expand">↕</span>"#);
2670 // Look for the example file in the source map if it exists, otherwise return a dummy span
2671 let file_span = (|| {
2672 let source_map = tcx.sess.source_map();
2673 let crate_src = tcx.sess.local_crate_source_file.as_ref()?;
2674 let abs_crate_src = crate_src.canonicalize().ok()?;
2675 let crate_root = abs_crate_src.parent()?.parent()?;
2676 let rel_path = path.strip_prefix(crate_root).ok()?;
2677 let files = source_map.files();
2678 let file = files.iter().find(|file| match &file.name {
2679 FileName::Real(RealFileName::LocalPath(other_path)) => rel_path == other_path,
2682 Some(rustc_span::Span::with_root_ctxt(
2683 file.start_pos + BytePos(byte_min),
2684 file.start_pos + BytePos(byte_max),
2687 .unwrap_or(rustc_span::DUMMY_SP);
2689 // The root path is the inverse of Context::current
2690 let root_path = vec!["../"; cx.current.len() - 1].join("");
2692 let mut decoration_info = FxHashMap::default();
2693 decoration_info.insert("highlight focus", vec![byte_ranges.remove(0)]);
2694 decoration_info.insert("highlight", byte_ranges);
2703 Some(highlight::DecorationInfo(decoration_info)),
2704 sources::SourceContext::Embedded { offset: line_min },
2706 write!(w, "</div></div>");
2711 // The call locations are output in sequence, so that sequence needs to be determined.
2712 // Ideally the most "relevant" examples would be shown first, but there's no general algorithm
2713 // for determining relevance. Instead, we prefer the smallest examples being likely the easiest to
2714 // understand at a glance.
2715 let ordered_locations = {
2716 let sort_criterion = |(_, call_data): &(_, &CallData)| {
2717 // Use the first location because that's what the user will see initially
2718 let (lo, hi) = call_data.locations[0].enclosing_item.byte_span;
2722 let mut locs = call_locations.into_iter().collect::<Vec<_>>();
2723 locs.sort_by_key(sort_criterion);
2727 let mut it = ordered_locations.into_iter().peekable();
2729 // An example may fail to write if its source can't be read for some reason, so this method
2730 // continues iterating until a write suceeds
2731 let write_and_skip_failure = |w: &mut Buffer, it: &mut Peekable<_>| {
2732 while let Some(example) = it.next() {
2733 if write_example(&mut *w, example) {
2739 // Write just one example that's visible by default in the method's description.
2740 write_and_skip_failure(w, &mut it);
2742 // Then add the remaining examples in a hidden section.
2743 if it.peek().is_some() {
2746 "<details class=\"rustdoc-toggle more-examples-toggle\">\
2747 <summary class=\"hideme\">\
2748 <span>More examples</span>\
2750 <div class=\"more-scraped-examples\">\
2751 <div class=\"toggle-line\"><div class=\"toggle-line-inner\"></div></div>\
2752 <div class=\"more-scraped-examples-inner\">"
2755 // Only generate inline code for MAX_FULL_EXAMPLES number of examples. Otherwise we could
2756 // make the page arbitrarily huge!
2757 for _ in 0..MAX_FULL_EXAMPLES {
2758 write_and_skip_failure(w, &mut it);
2761 // For the remaining examples, generate a <ul> containing links to the source files.
2762 if it.peek().is_some() {
2763 write!(w, r#"<div class="example-links">Additional examples can be found in:<br><ul>"#);
2764 it.for_each(|(_, call_data)| {
2765 let (url, _) = link_to_loc(&call_data, &call_data.locations[0]);
2768 r#"<li><a href="{url}">{name}</a></li>"#,
2770 name = call_data.display_name
2773 write!(w, "</ul></div>");
2776 write!(w, "</div></div></details>");
2779 write!(w, "</div>");