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Diffstat (limited to 'src/librustdoc/html/render/mod.rs')
| -rw-r--r-- | src/librustdoc/html/render/mod.rs | 2849 |
1 files changed, 2849 insertions, 0 deletions
diff --git a/src/librustdoc/html/render/mod.rs b/src/librustdoc/html/render/mod.rs new file mode 100644 index 000000000..a262c8f7d --- /dev/null +++ b/src/librustdoc/html/render/mod.rs @@ -0,0 +1,2849 @@ +//! Rustdoc's HTML rendering module. +//! +//! This modules contains the bulk of the logic necessary for rendering a +//! rustdoc `clean::Crate` instance to a set of static HTML pages. This +//! rendering process is largely driven by the `format!` syntax extension to +//! perform all I/O into files and streams. +//! +//! The rendering process is largely driven by the `Context` and `Cache` +//! structures. The cache is pre-populated by crawling the crate in question, +//! and then it is shared among the various rendering threads. The cache is meant +//! to be a fairly large structure not implementing `Clone` (because it's shared +//! among threads). The context, however, should be a lightweight structure. This +//! is cloned per-thread and contains information about what is currently being +//! rendered. +//! +//! In order to speed up rendering (mostly because of markdown rendering), the +//! rendering process has been parallelized. This parallelization is only +//! exposed through the `crate` method on the context, and then also from the +//! fact that the shared cache is stored in TLS (and must be accessed as such). +//! +//! In addition to rendering the crate itself, this module is also responsible +//! for creating the corresponding search index and source file renderings. +//! These threads are not parallelized (they haven't been a bottleneck yet), and +//! both occur before the crate is rendered. + +pub(crate) mod search_index; + +#[cfg(test)] +mod tests; + +mod context; +mod print_item; +mod span_map; +mod write_shared; + +pub(crate) use self::context::*; +pub(crate) use self::span_map::{collect_spans_and_sources, LinkFromSrc}; + +use std::collections::VecDeque; +use std::default::Default; +use std::fmt; +use std::fs; +use std::iter::Peekable; +use std::path::PathBuf; +use std::rc::Rc; +use std::str; +use std::string::ToString; + +use rustc_ast_pretty::pprust; +use rustc_attr::{ConstStability, Deprecation, StabilityLevel}; +use rustc_data_structures::fx::{FxHashMap, FxHashSet}; +use rustc_hir::def::CtorKind; +use rustc_hir::def_id::DefId; +use rustc_hir::Mutability; +use rustc_middle::middle::stability; +use rustc_middle::ty; +use rustc_middle::ty::TyCtxt; +use rustc_span::{ + symbol::{sym, Symbol}, + BytePos, FileName, RealFileName, +}; +use serde::ser::SerializeSeq; +use serde::{Serialize, Serializer}; + +use crate::clean::{self, ItemId, RenderedLink, SelfTy}; +use crate::error::Error; +use crate::formats::cache::Cache; +use crate::formats::item_type::ItemType; +use crate::formats::{AssocItemRender, Impl, RenderMode}; +use crate::html::escape::Escape; +use crate::html::format::{ + href, join_with_double_colon, print_abi_with_space, print_constness_with_space, + print_default_space, print_generic_bounds, print_where_clause, Buffer, Ending, HrefError, + PrintWithSpace, +}; +use crate::html::highlight; +use crate::html::markdown::{HeadingOffset, IdMap, Markdown, MarkdownHtml, MarkdownSummaryLine}; +use crate::html::sources; +use crate::html::static_files::SCRAPE_EXAMPLES_HELP_MD; +use crate::scrape_examples::{CallData, CallLocation}; +use crate::try_none; +use crate::DOC_RUST_LANG_ORG_CHANNEL; + +/// A pair of name and its optional document. +pub(crate) type NameDoc = (String, Option<String>); + +pub(crate) fn ensure_trailing_slash(v: &str) -> impl fmt::Display + '_ { + crate::html::format::display_fn(move |f| { + if !v.ends_with('/') && !v.is_empty() { write!(f, "{}/", v) } else { f.write_str(v) } + }) +} + +// Helper structs for rendering items/sidebars and carrying along contextual +// information + +/// Struct representing one entry in the JS search index. These are all emitted +/// by hand to a large JS file at the end of cache-creation. +#[derive(Debug)] +pub(crate) struct IndexItem { + pub(crate) ty: ItemType, + pub(crate) name: String, + pub(crate) path: String, + pub(crate) desc: String, + pub(crate) parent: Option<DefId>, + pub(crate) parent_idx: Option<usize>, + pub(crate) search_type: Option<IndexItemFunctionType>, + pub(crate) aliases: Box<[Symbol]>, +} + +/// A type used for the search index. +#[derive(Debug)] +pub(crate) struct RenderType { + id: Option<RenderTypeId>, + generics: Option<Vec<RenderType>>, +} + +impl Serialize for RenderType { + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + let id = match &self.id { + // 0 is a sentinel, everything else is one-indexed + None => 0, + Some(RenderTypeId::Index(idx)) => idx + 1, + _ => panic!("must convert render types to indexes before serializing"), + }; + if let Some(generics) = &self.generics { + let mut seq = serializer.serialize_seq(None)?; + seq.serialize_element(&id)?; + seq.serialize_element(generics)?; + seq.end() + } else { + id.serialize(serializer) + } + } +} + +#[derive(Clone, Debug)] +pub(crate) enum RenderTypeId { + DefId(DefId), + Primitive(clean::PrimitiveType), + Index(usize), +} + +/// Full type of functions/methods in the search index. +#[derive(Debug)] +pub(crate) struct IndexItemFunctionType { + inputs: Vec<RenderType>, + output: Vec<RenderType>, +} + +impl Serialize for IndexItemFunctionType { + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + // If we couldn't figure out a type, just write `0`. + let has_missing = self + .inputs + .iter() + .chain(self.output.iter()) + .any(|i| i.id.is_none() && i.generics.is_none()); + if has_missing { + 0.serialize(serializer) + } else { + let mut seq = serializer.serialize_seq(None)?; + match &self.inputs[..] { + [one] if one.generics.is_none() => seq.serialize_element(one)?, + _ => seq.serialize_element(&self.inputs)?, + } + match &self.output[..] { + [] => {} + [one] if one.generics.is_none() => seq.serialize_element(one)?, + _ => seq.serialize_element(&self.output)?, + } + seq.end() + } + } +} + +#[derive(Debug, Clone)] +pub(crate) struct StylePath { + /// The path to the theme + pub(crate) path: PathBuf, +} + +impl StylePath { + pub(crate) fn basename(&self) -> Result<String, Error> { + Ok(try_none!(try_none!(self.path.file_stem(), &self.path).to_str(), &self.path).to_string()) + } +} + +fn write_srclink(cx: &Context<'_>, item: &clean::Item, buf: &mut Buffer) { + if let Some(l) = cx.src_href(item) { + write!(buf, "<a class=\"srclink\" href=\"{}\">source</a>", l) + } +} + +#[derive(Debug, Eq, PartialEq, Hash)] +struct ItemEntry { + url: String, + name: String, +} + +impl ItemEntry { + fn new(mut url: String, name: String) -> ItemEntry { + while url.starts_with('/') { + url.remove(0); + } + ItemEntry { url, name } + } +} + +impl ItemEntry { + pub(crate) fn print(&self) -> impl fmt::Display + '_ { + crate::html::format::display_fn(move |f| { + write!(f, "<a href=\"{}\">{}</a>", self.url, Escape(&self.name)) + }) + } +} + +impl PartialOrd for ItemEntry { + fn partial_cmp(&self, other: &ItemEntry) -> Option<::std::cmp::Ordering> { + Some(self.cmp(other)) + } +} + +impl Ord for ItemEntry { + fn cmp(&self, other: &ItemEntry) -> ::std::cmp::Ordering { + self.name.cmp(&other.name) + } +} + +#[derive(Debug)] +struct AllTypes { + structs: FxHashSet<ItemEntry>, + enums: FxHashSet<ItemEntry>, + unions: FxHashSet<ItemEntry>, + primitives: FxHashSet<ItemEntry>, + traits: FxHashSet<ItemEntry>, + macros: FxHashSet<ItemEntry>, + functions: FxHashSet<ItemEntry>, + typedefs: FxHashSet<ItemEntry>, + opaque_tys: FxHashSet<ItemEntry>, + statics: FxHashSet<ItemEntry>, + constants: FxHashSet<ItemEntry>, + attributes: FxHashSet<ItemEntry>, + derives: FxHashSet<ItemEntry>, + trait_aliases: FxHashSet<ItemEntry>, +} + +impl AllTypes { + fn new() -> AllTypes { + let new_set = |cap| FxHashSet::with_capacity_and_hasher(cap, Default::default()); + AllTypes { + structs: new_set(100), + enums: new_set(100), + unions: new_set(100), + primitives: new_set(26), + traits: new_set(100), + macros: new_set(100), + functions: new_set(100), + typedefs: new_set(100), + opaque_tys: new_set(100), + statics: new_set(100), + constants: new_set(100), + attributes: new_set(100), + derives: new_set(100), + trait_aliases: new_set(100), + } + } + + fn append(&mut self, item_name: String, item_type: &ItemType) { + let mut url: Vec<_> = item_name.split("::").skip(1).collect(); + if let Some(name) = url.pop() { + let new_url = format!("{}/{}.{}.html", url.join("/"), item_type, name); + url.push(name); + let name = url.join("::"); + match *item_type { + ItemType::Struct => self.structs.insert(ItemEntry::new(new_url, name)), + ItemType::Enum => self.enums.insert(ItemEntry::new(new_url, name)), + ItemType::Union => self.unions.insert(ItemEntry::new(new_url, name)), + ItemType::Primitive => self.primitives.insert(ItemEntry::new(new_url, name)), + ItemType::Trait => self.traits.insert(ItemEntry::new(new_url, name)), + ItemType::Macro => self.macros.insert(ItemEntry::new(new_url, name)), + ItemType::Function => self.functions.insert(ItemEntry::new(new_url, name)), + ItemType::Typedef => self.typedefs.insert(ItemEntry::new(new_url, name)), + ItemType::OpaqueTy => self.opaque_tys.insert(ItemEntry::new(new_url, name)), + ItemType::Static => self.statics.insert(ItemEntry::new(new_url, name)), + ItemType::Constant => self.constants.insert(ItemEntry::new(new_url, name)), + ItemType::ProcAttribute => self.attributes.insert(ItemEntry::new(new_url, name)), + ItemType::ProcDerive => self.derives.insert(ItemEntry::new(new_url, name)), + ItemType::TraitAlias => self.trait_aliases.insert(ItemEntry::new(new_url, name)), + _ => true, + }; + } + } +} + +impl AllTypes { + fn print(self, f: &mut Buffer) { + fn print_entries(f: &mut Buffer, e: &FxHashSet<ItemEntry>, title: &str, class: &str) { + if !e.is_empty() { + let mut e: Vec<&ItemEntry> = e.iter().collect(); + e.sort(); + write!( + f, + "<h3 id=\"{}\">{}</h3><ul class=\"{} docblock\">", + title.replace(' ', "-"), // IDs cannot contain whitespaces. + title, + class + ); + + for s in e.iter() { + write!(f, "<li>{}</li>", s.print()); + } + + f.write_str("</ul>"); + } + } + + f.write_str( + "<h1 class=\"fqn\">\ + <span class=\"in-band\">List of all items</span>\ + </h1>", + ); + // Note: print_entries does not escape the title, because we know the current set of titles + // doesn't require escaping. + print_entries(f, &self.structs, "Structs", "structs"); + print_entries(f, &self.enums, "Enums", "enums"); + print_entries(f, &self.unions, "Unions", "unions"); + print_entries(f, &self.primitives, "Primitives", "primitives"); + print_entries(f, &self.traits, "Traits", "traits"); + print_entries(f, &self.macros, "Macros", "macros"); + print_entries(f, &self.attributes, "Attribute Macros", "attributes"); + print_entries(f, &self.derives, "Derive Macros", "derives"); + print_entries(f, &self.functions, "Functions", "functions"); + print_entries(f, &self.typedefs, "Typedefs", "typedefs"); + print_entries(f, &self.trait_aliases, "Trait Aliases", "trait-aliases"); + print_entries(f, &self.opaque_tys, "Opaque Types", "opaque-types"); + print_entries(f, &self.statics, "Statics", "statics"); + print_entries(f, &self.constants, "Constants", "constants") + } +} + +fn scrape_examples_help(shared: &SharedContext<'_>) -> String { + let mut content = SCRAPE_EXAMPLES_HELP_MD.to_owned(); + content.push_str(&format!( + "## More information\n\n\ + If you want more information about this feature, please read the [corresponding chapter in the Rustdoc book]({}/rustdoc/scraped-examples.html).", + DOC_RUST_LANG_ORG_CHANNEL)); + + let mut ids = IdMap::default(); + format!( + "<div class=\"main-heading\">\ + <h1 class=\"fqn\">\ + <span class=\"in-band\">About scraped examples</span>\ + </h1>\ + </div>\ + <div>{}</div>", + Markdown { + content: &content, + links: &[], + ids: &mut ids, + error_codes: shared.codes, + edition: shared.edition(), + playground: &shared.playground, + heading_offset: HeadingOffset::H1 + } + .into_string() + ) +} + +fn document( + w: &mut Buffer, + cx: &mut Context<'_>, + item: &clean::Item, + parent: Option<&clean::Item>, + heading_offset: HeadingOffset, +) { + if let Some(ref name) = item.name { + info!("Documenting {}", name); + } + document_item_info(w, cx, item, parent); + if parent.is_none() { + document_full_collapsible(w, item, cx, heading_offset); + } else { + document_full(w, item, cx, heading_offset); + } +} + +/// Render md_text as markdown. +fn render_markdown( + w: &mut Buffer, + cx: &mut Context<'_>, + md_text: &str, + links: Vec<RenderedLink>, + heading_offset: HeadingOffset, +) { + write!( + w, + "<div class=\"docblock\">{}</div>", + Markdown { + content: md_text, + links: &links, + ids: &mut cx.id_map, + error_codes: cx.shared.codes, + edition: cx.shared.edition(), + playground: &cx.shared.playground, + heading_offset, + } + .into_string() + ) +} + +/// Writes a documentation block containing only the first paragraph of the documentation. If the +/// docs are longer, a "Read more" link is appended to the end. +fn document_short( + w: &mut Buffer, + item: &clean::Item, + cx: &mut Context<'_>, + link: AssocItemLink<'_>, + parent: &clean::Item, + show_def_docs: bool, +) { + document_item_info(w, cx, item, Some(parent)); + if !show_def_docs { + return; + } + if let Some(s) = item.doc_value() { + let mut summary_html = MarkdownSummaryLine(&s, &item.links(cx)).into_string(); + + if s.contains('\n') { + let link = format!(r#" <a{}>Read more</a>"#, assoc_href_attr(item, link, cx)); + + if let Some(idx) = summary_html.rfind("</p>") { + summary_html.insert_str(idx, &link); + } else { + summary_html.push_str(&link); + } + } + + write!(w, "<div class='docblock'>{}</div>", summary_html,); + } +} + +fn document_full_collapsible( + w: &mut Buffer, + item: &clean::Item, + cx: &mut Context<'_>, + heading_offset: HeadingOffset, +) { + document_full_inner(w, item, cx, true, heading_offset); +} + +fn document_full( + w: &mut Buffer, + item: &clean::Item, + cx: &mut Context<'_>, + heading_offset: HeadingOffset, +) { + document_full_inner(w, item, cx, false, heading_offset); +} + +fn document_full_inner( + w: &mut Buffer, + item: &clean::Item, + cx: &mut Context<'_>, + is_collapsible: bool, + heading_offset: HeadingOffset, +) { + if let Some(s) = item.collapsed_doc_value() { + debug!("Doc block: =====\n{}\n=====", s); + if is_collapsible { + w.write_str( + "<details class=\"rustdoc-toggle top-doc\" open>\ + <summary class=\"hideme\">\ + <span>Expand description</span>\ + </summary>", + ); + render_markdown(w, cx, &s, item.links(cx), heading_offset); + w.write_str("</details>"); + } else { + render_markdown(w, cx, &s, item.links(cx), heading_offset); + } + } + + let kind = match &*item.kind { + clean::ItemKind::StrippedItem(box kind) | kind => kind, + }; + + if let clean::ItemKind::FunctionItem(..) | clean::ItemKind::MethodItem(..) = kind { + render_call_locations(w, cx, item); + } +} + +/// Add extra information about an item such as: +/// +/// * Stability +/// * Deprecated +/// * Required features (through the `doc_cfg` feature) +fn document_item_info( + w: &mut Buffer, + cx: &mut Context<'_>, + item: &clean::Item, + parent: Option<&clean::Item>, +) { + let item_infos = short_item_info(item, cx, parent); + if !item_infos.is_empty() { + w.write_str("<span class=\"item-info\">"); + for info in item_infos { + w.write_str(&info); + } + w.write_str("</span>"); + } +} + +fn portability(item: &clean::Item, parent: Option<&clean::Item>) -> Option<String> { + let cfg = match (&item.cfg, parent.and_then(|p| p.cfg.as_ref())) { + (Some(cfg), Some(parent_cfg)) => cfg.simplify_with(parent_cfg), + (cfg, _) => cfg.as_deref().cloned(), + }; + + debug!("Portability {:?} - {:?} = {:?}", item.cfg, parent.and_then(|p| p.cfg.as_ref()), cfg); + + Some(format!("<div class=\"stab portability\">{}</div>", cfg?.render_long_html())) +} + +/// Render the stability, deprecation and portability information that is displayed at the top of +/// the item's documentation. +fn short_item_info( + item: &clean::Item, + cx: &mut Context<'_>, + parent: Option<&clean::Item>, +) -> Vec<String> { + let mut extra_info = vec![]; + let error_codes = cx.shared.codes; + + if let Some(depr @ Deprecation { note, since, is_since_rustc_version: _, suggestion: _ }) = + item.deprecation(cx.tcx()) + { + // We display deprecation messages for #[deprecated], but only display + // the future-deprecation messages for rustc versions. + let mut message = if let Some(since) = since { + let since = since.as_str(); + if !stability::deprecation_in_effect(&depr) { + if since == "TBD" { + String::from("Deprecating in a future Rust version") + } else { + format!("Deprecating in {}", Escape(since)) + } + } else { + format!("Deprecated since {}", Escape(since)) + } + } else { + String::from("Deprecated") + }; + + if let Some(note) = note { + let note = note.as_str(); + let html = MarkdownHtml( + note, + &mut cx.id_map, + error_codes, + cx.shared.edition(), + &cx.shared.playground, + ); + message.push_str(&format!(": {}", html.into_string())); + } + extra_info.push(format!( + "<div class=\"stab deprecated\"><span class=\"emoji\">👎</span> {}</div>", + message, + )); + } + + // Render unstable items. But don't render "rustc_private" crates (internal compiler crates). + // Those crates are permanently unstable so it makes no sense to render "unstable" everywhere. + if let Some((StabilityLevel::Unstable { reason: _, issue, .. }, feature)) = item + .stability(cx.tcx()) + .as_ref() + .filter(|stab| stab.feature != sym::rustc_private) + .map(|stab| (stab.level, stab.feature)) + { + let mut message = + "<span class=\"emoji\">🔬</span> This is a nightly-only experimental API.".to_owned(); + + let mut feature = format!("<code>{}</code>", Escape(feature.as_str())); + if let (Some(url), Some(issue)) = (&cx.shared.issue_tracker_base_url, issue) { + feature.push_str(&format!( + " <a href=\"{url}{issue}\">#{issue}</a>", + url = url, + issue = issue + )); + } + + message.push_str(&format!(" ({})", feature)); + + extra_info.push(format!("<div class=\"stab unstable\">{}</div>", message)); + } + + if let Some(portability) = portability(item, parent) { + extra_info.push(portability); + } + + extra_info +} + +// Render the list of items inside one of the sections "Trait Implementations", +// "Auto Trait Implementations," "Blanket Trait Implementations" (on struct/enum pages). +fn render_impls( + cx: &mut Context<'_>, + w: &mut Buffer, + impls: &[&&Impl], + containing_item: &clean::Item, + toggle_open_by_default: bool, +) { + let tcx = cx.tcx(); + let mut rendered_impls = impls + .iter() + .map(|i| { + let did = i.trait_did().unwrap(); + let provided_trait_methods = i.inner_impl().provided_trait_methods(tcx); + let assoc_link = AssocItemLink::GotoSource(did.into(), &provided_trait_methods); + let mut buffer = if w.is_for_html() { Buffer::html() } else { Buffer::new() }; + render_impl( + &mut buffer, + cx, + i, + containing_item, + assoc_link, + RenderMode::Normal, + None, + &[], + ImplRenderingParameters { + show_def_docs: true, + show_default_items: true, + show_non_assoc_items: true, + toggle_open_by_default, + }, + ); + buffer.into_inner() + }) + .collect::<Vec<_>>(); + rendered_impls.sort(); + w.write_str(&rendered_impls.join("")); +} + +/// Build a (possibly empty) `href` attribute (a key-value pair) for the given associated item. +fn assoc_href_attr(it: &clean::Item, link: AssocItemLink<'_>, cx: &Context<'_>) -> String { + let name = it.name.unwrap(); + let item_type = it.type_(); + + let href = match link { + AssocItemLink::Anchor(Some(ref id)) => Some(format!("#{}", id)), + AssocItemLink::Anchor(None) => Some(format!("#{}.{}", item_type, name)), + AssocItemLink::GotoSource(did, provided_methods) => { + // We're creating a link from the implementation of an associated item to its + // declaration in the trait declaration. + let item_type = match item_type { + // For historical but not technical reasons, the item type of methods in + // trait declarations depends on whether the method is required (`TyMethod`) or + // provided (`Method`). + ItemType::Method | ItemType::TyMethod => { + if provided_methods.contains(&name) { + ItemType::Method + } else { + ItemType::TyMethod + } + } + // For associated types and constants, no such distinction exists. + item_type => item_type, + }; + + match href(did.expect_def_id(), cx) { + Ok((url, ..)) => Some(format!("{}#{}.{}", url, item_type, name)), + // The link is broken since it points to an external crate that wasn't documented. + // Do not create any link in such case. This is better than falling back to a + // dummy anchor like `#{item_type}.{name}` representing the `id` of *this* impl item + // (that used to happen in older versions). Indeed, in most cases this dummy would + // coincide with the `id`. However, it would not always do so. + // In general, this dummy would be incorrect: + // If the type with the trait impl also had an inherent impl with an assoc. item of + // the *same* name as this impl item, the dummy would link to that one even though + // those two items are distinct! + // In this scenario, the actual `id` of this impl item would be + // `#{item_type}.{name}-{n}` for some number `n` (a disambiguator). + Err(HrefError::DocumentationNotBuilt) => None, + Err(_) => Some(format!("#{}.{}", item_type, name)), + } + } + }; + + // If there is no `href` for the reason explained above, simply do not render it which is valid: + // https://html.spec.whatwg.org/multipage/links.html#links-created-by-a-and-area-elements + href.map(|href| format!(" href=\"{}\"", href)).unwrap_or_default() +} + +fn assoc_const( + w: &mut Buffer, + it: &clean::Item, + ty: &clean::Type, + default: Option<&clean::ConstantKind>, + link: AssocItemLink<'_>, + extra: &str, + cx: &Context<'_>, +) { + write!( + w, + "{extra}{vis}const <a{href} class=\"constant\">{name}</a>: {ty}", + extra = extra, + vis = it.visibility.print_with_space(it.item_id, cx), + href = assoc_href_attr(it, link, cx), + name = it.name.as_ref().unwrap(), + ty = ty.print(cx), + ); + if let Some(default) = default { + write!(w, " = "); + + // FIXME: `.value()` uses `clean::utils::format_integer_with_underscore_sep` under the + // hood which adds noisy underscores and a type suffix to number literals. + // This hurts readability in this context especially when more complex expressions + // are involved and it doesn't add much of value. + // Find a way to print constants here without all that jazz. + write!(w, "{}", Escape(&default.value(cx.tcx()).unwrap_or_else(|| default.expr(cx.tcx())))); + } +} + +fn assoc_type( + w: &mut Buffer, + it: &clean::Item, + generics: &clean::Generics, + bounds: &[clean::GenericBound], + default: Option<&clean::Type>, + link: AssocItemLink<'_>, + indent: usize, + cx: &Context<'_>, +) { + write!( + w, + "{indent}type <a{href} class=\"associatedtype\">{name}</a>{generics}", + indent = " ".repeat(indent), + href = assoc_href_attr(it, link, cx), + name = it.name.as_ref().unwrap(), + generics = generics.print(cx), + ); + if !bounds.is_empty() { + write!(w, ": {}", print_generic_bounds(bounds, cx)) + } + write!(w, "{}", print_where_clause(generics, cx, indent, Ending::NoNewline)); + if let Some(default) = default { + write!(w, " = {}", default.print(cx)) + } +} + +fn assoc_method( + w: &mut Buffer, + meth: &clean::Item, + g: &clean::Generics, + d: &clean::FnDecl, + link: AssocItemLink<'_>, + parent: ItemType, + cx: &Context<'_>, + render_mode: RenderMode, +) { + let header = meth.fn_header(cx.tcx()).expect("Trying to get header from a non-function item"); + let name = meth.name.as_ref().unwrap(); + let vis = meth.visibility.print_with_space(meth.item_id, cx).to_string(); + // FIXME: Once https://github.com/rust-lang/rust/issues/67792 is implemented, we can remove + // this condition. + let constness = match render_mode { + RenderMode::Normal => { + print_constness_with_space(&header.constness, meth.const_stability(cx.tcx())) + } + RenderMode::ForDeref { .. } => "", + }; + let asyncness = header.asyncness.print_with_space(); + let unsafety = header.unsafety.print_with_space(); + let defaultness = print_default_space(meth.is_default()); + let abi = print_abi_with_space(header.abi).to_string(); + let href = assoc_href_attr(meth, link, cx); + + // NOTE: `{:#}` does not print HTML formatting, `{}` does. So `g.print` can't be reused between the length calculation and `write!`. + let generics_len = format!("{:#}", g.print(cx)).len(); + let mut header_len = "fn ".len() + + vis.len() + + constness.len() + + asyncness.len() + + unsafety.len() + + defaultness.len() + + abi.len() + + name.as_str().len() + + generics_len; + + let (indent, indent_str, end_newline) = if parent == ItemType::Trait { + header_len += 4; + let indent_str = " "; + render_attributes_in_pre(w, meth, indent_str); + (4, indent_str, Ending::NoNewline) + } else { + render_attributes_in_code(w, meth); + (0, "", Ending::Newline) + }; + w.reserve(header_len + "<a href=\"\" class=\"fnname\">{".len() + "</a>".len()); + write!( + w, + "{indent}{vis}{constness}{asyncness}{unsafety}{defaultness}{abi}fn <a{href} class=\"fnname\">{name}</a>\ + {generics}{decl}{notable_traits}{where_clause}", + indent = indent_str, + vis = vis, + constness = constness, + asyncness = asyncness, + unsafety = unsafety, + defaultness = defaultness, + abi = abi, + href = href, + name = name, + generics = g.print(cx), + decl = d.full_print(header_len, indent, header.asyncness, cx), + notable_traits = notable_traits_decl(d, cx), + where_clause = print_where_clause(g, cx, indent, end_newline), + ) +} + +/// Writes a span containing the versions at which an item became stable and/or const-stable. For +/// example, if the item became stable at 1.0.0, and const-stable at 1.45.0, this function would +/// write a span containing "1.0.0 (const: 1.45.0)". +/// +/// Returns `true` if a stability annotation was rendered. +/// +/// Stability and const-stability are considered separately. If the item is unstable, no version +/// will be written. If the item is const-unstable, "const: unstable" will be appended to the +/// span, with a link to the tracking issue if present. If an item's stability or const-stability +/// version matches the version of its enclosing item, that version will be omitted. +/// +/// Note that it is possible for an unstable function to be const-stable. In that case, the span +/// will include the const-stable version, but no stable version will be emitted, as a natural +/// consequence of the above rules. +fn render_stability_since_raw( + w: &mut Buffer, + ver: Option<Symbol>, + const_stability: Option<ConstStability>, + containing_ver: Option<Symbol>, + containing_const_ver: Option<Symbol>, +) -> bool { + let stable_version = ver.filter(|inner| !inner.is_empty() && Some(*inner) != containing_ver); + + let mut title = String::new(); + let mut stability = String::new(); + + if let Some(ver) = stable_version { + stability.push_str(ver.as_str()); + title.push_str(&format!("Stable since Rust version {}", ver)); + } + + let const_title_and_stability = match const_stability { + Some(ConstStability { level: StabilityLevel::Stable { since, .. }, .. }) + if Some(since) != containing_const_ver => + { + Some((format!("const since {}", since), format!("const: {}", since))) + } + Some(ConstStability { level: StabilityLevel::Unstable { issue, .. }, feature, .. }) => { + let unstable = if let Some(n) = issue { + format!( + r#"<a href="https://github.com/rust-lang/rust/issues/{}" title="Tracking issue for {}">unstable</a>"#, + n, feature + ) + } else { + String::from("unstable") + }; + + Some((String::from("const unstable"), format!("const: {}", unstable))) + } + _ => None, + }; + + if let Some((const_title, const_stability)) = const_title_and_stability { + if !title.is_empty() { + title.push_str(&format!(", {}", const_title)); + } else { + title.push_str(&const_title); + } + + if !stability.is_empty() { + stability.push_str(&format!(" ({})", const_stability)); + } else { + stability.push_str(&const_stability); + } + } + + if !stability.is_empty() { + write!(w, r#"<span class="since" title="{}">{}</span>"#, title, stability); + } + + !stability.is_empty() +} + +fn render_assoc_item( + w: &mut Buffer, + item: &clean::Item, + link: AssocItemLink<'_>, + parent: ItemType, + cx: &Context<'_>, + render_mode: RenderMode, +) { + match &*item.kind { + clean::StrippedItem(..) => {} + clean::TyMethodItem(m) => { + assoc_method(w, item, &m.generics, &m.decl, link, parent, cx, render_mode) + } + clean::MethodItem(m, _) => { + assoc_method(w, item, &m.generics, &m.decl, link, parent, cx, render_mode) + } + kind @ (clean::TyAssocConstItem(ty) | clean::AssocConstItem(ty, _)) => assoc_const( + w, + item, + ty, + match kind { + clean::TyAssocConstItem(_) => None, + clean::AssocConstItem(_, default) => Some(default), + _ => unreachable!(), + }, + link, + if parent == ItemType::Trait { " " } else { "" }, + cx, + ), + clean::TyAssocTypeItem(ref generics, ref bounds) => assoc_type( + w, + item, + generics, + bounds, + None, + link, + if parent == ItemType::Trait { 4 } else { 0 }, + cx, + ), + clean::AssocTypeItem(ref ty, ref bounds) => assoc_type( + w, + item, + &ty.generics, + bounds, + Some(ty.item_type.as_ref().unwrap_or(&ty.type_)), + link, + if parent == ItemType::Trait { 4 } else { 0 }, + cx, + ), + _ => panic!("render_assoc_item called on non-associated-item"), + } +} + +const ALLOWED_ATTRIBUTES: &[Symbol] = + &[sym::export_name, sym::link_section, sym::no_mangle, sym::repr, sym::non_exhaustive]; + +fn attributes(it: &clean::Item) -> Vec<String> { + it.attrs + .other_attrs + .iter() + .filter_map(|attr| { + if ALLOWED_ATTRIBUTES.contains(&attr.name_or_empty()) { + Some( + pprust::attribute_to_string(attr) + .replace("\\\n", "") + .replace('\n', "") + .replace(" ", " "), + ) + } else { + None + } + }) + .collect() +} + +// When an attribute is rendered inside a `<pre>` tag, it is formatted using +// a whitespace prefix and newline. +fn render_attributes_in_pre(w: &mut Buffer, it: &clean::Item, prefix: &str) { + for a in attributes(it) { + writeln!(w, "{}{}", prefix, a); + } +} + +// When an attribute is rendered inside a <code> tag, it is formatted using +// a div to produce a newline after it. +fn render_attributes_in_code(w: &mut Buffer, it: &clean::Item) { + for a in attributes(it) { + write!(w, "<div class=\"code-attribute\">{}</div>", a); + } +} + +#[derive(Copy, Clone)] +enum AssocItemLink<'a> { + Anchor(Option<&'a str>), + GotoSource(ItemId, &'a FxHashSet<Symbol>), +} + +impl<'a> AssocItemLink<'a> { + fn anchor(&self, id: &'a str) -> Self { + match *self { + AssocItemLink::Anchor(_) => AssocItemLink::Anchor(Some(id)), + ref other => *other, + } + } +} + +fn render_assoc_items( + w: &mut Buffer, + cx: &mut Context<'_>, + containing_item: &clean::Item, + it: DefId, + what: AssocItemRender<'_>, +) { + let mut derefs = FxHashSet::default(); + derefs.insert(it); + render_assoc_items_inner(w, cx, containing_item, it, what, &mut derefs) +} + +fn render_assoc_items_inner( + w: &mut Buffer, + cx: &mut Context<'_>, + containing_item: &clean::Item, + it: DefId, + what: AssocItemRender<'_>, + derefs: &mut FxHashSet<DefId>, +) { + info!("Documenting associated items of {:?}", containing_item.name); + let shared = Rc::clone(&cx.shared); + let cache = &shared.cache; + let Some(v) = cache.impls.get(&it) else { return }; + let (non_trait, traits): (Vec<_>, _) = v.iter().partition(|i| i.inner_impl().trait_.is_none()); + if !non_trait.is_empty() { + let mut tmp_buf = Buffer::empty_from(w); + let (render_mode, id) = match what { + AssocItemRender::All => { + tmp_buf.write_str( + "<h2 id=\"implementations\" class=\"small-section-header\">\ + Implementations\ + <a href=\"#implementations\" class=\"anchor\"></a>\ + </h2>", + ); + (RenderMode::Normal, "implementations-list".to_owned()) + } + AssocItemRender::DerefFor { trait_, type_, deref_mut_ } => { + let id = + cx.derive_id(small_url_encode(format!("deref-methods-{:#}", type_.print(cx)))); + if let Some(def_id) = type_.def_id(cx.cache()) { + cx.deref_id_map.insert(def_id, id.clone()); + } + write!( + tmp_buf, + "<h2 id=\"{id}\" class=\"small-section-header\">\ + <span>Methods from {trait_}<Target = {type_}></span>\ + <a href=\"#{id}\" class=\"anchor\"></a>\ + </h2>", + id = id, + trait_ = trait_.print(cx), + type_ = type_.print(cx), + ); + (RenderMode::ForDeref { mut_: deref_mut_ }, cx.derive_id(id)) + } + }; + let mut impls_buf = Buffer::empty_from(w); + for i in &non_trait { + render_impl( + &mut impls_buf, + cx, + i, + containing_item, + AssocItemLink::Anchor(None), + render_mode, + None, + &[], + ImplRenderingParameters { + show_def_docs: true, + show_default_items: true, + show_non_assoc_items: true, + toggle_open_by_default: true, + }, + ); + } + if !impls_buf.is_empty() { + w.push_buffer(tmp_buf); + write!(w, "<div id=\"{}\">", id); + w.push_buffer(impls_buf); + w.write_str("</div>"); + } + } + + if !traits.is_empty() { + let deref_impl = + traits.iter().find(|t| t.trait_did() == cx.tcx().lang_items().deref_trait()); + if let Some(impl_) = deref_impl { + let has_deref_mut = + traits.iter().any(|t| t.trait_did() == cx.tcx().lang_items().deref_mut_trait()); + render_deref_methods(w, cx, impl_, containing_item, has_deref_mut, derefs); + } + + // If we were already one level into rendering deref methods, we don't want to render + // anything after recursing into any further deref methods above. + if let AssocItemRender::DerefFor { .. } = what { + return; + } + + let (synthetic, concrete): (Vec<&&Impl>, Vec<&&Impl>) = + traits.iter().partition(|t| t.inner_impl().kind.is_auto()); + let (blanket_impl, concrete): (Vec<&&Impl>, _) = + concrete.into_iter().partition(|t| t.inner_impl().kind.is_blanket()); + + let mut impls = Buffer::empty_from(w); + render_impls(cx, &mut impls, &concrete, containing_item, true); + let impls = impls.into_inner(); + if !impls.is_empty() { + write!( + w, + "<h2 id=\"trait-implementations\" class=\"small-section-header\">\ + Trait Implementations\ + <a href=\"#trait-implementations\" class=\"anchor\"></a>\ + </h2>\ + <div id=\"trait-implementations-list\">{}</div>", + impls + ); + } + + if !synthetic.is_empty() { + w.write_str( + "<h2 id=\"synthetic-implementations\" class=\"small-section-header\">\ + Auto Trait Implementations\ + <a href=\"#synthetic-implementations\" class=\"anchor\"></a>\ + </h2>\ + <div id=\"synthetic-implementations-list\">", + ); + render_impls(cx, w, &synthetic, containing_item, false); + w.write_str("</div>"); + } + + if !blanket_impl.is_empty() { + w.write_str( + "<h2 id=\"blanket-implementations\" class=\"small-section-header\">\ + Blanket Implementations\ + <a href=\"#blanket-implementations\" class=\"anchor\"></a>\ + </h2>\ + <div id=\"blanket-implementations-list\">", + ); + render_impls(cx, w, &blanket_impl, containing_item, false); + w.write_str("</div>"); + } + } +} + +fn render_deref_methods( + w: &mut Buffer, + cx: &mut Context<'_>, + impl_: &Impl, + container_item: &clean::Item, + deref_mut: bool, + derefs: &mut FxHashSet<DefId>, +) { + let cache = cx.cache(); + let deref_type = impl_.inner_impl().trait_.as_ref().unwrap(); + let (target, real_target) = impl_ + .inner_impl() + .items + .iter() + .find_map(|item| match *item.kind { + clean::AssocTypeItem(box ref t, _) => Some(match *t { + clean::Typedef { item_type: Some(ref type_), .. } => (type_, &t.type_), + _ => (&t.type_, &t.type_), + }), + _ => None, + }) + .expect("Expected associated type binding"); + debug!("Render deref methods for {:#?}, target {:#?}", impl_.inner_impl().for_, target); + let what = + AssocItemRender::DerefFor { trait_: deref_type, type_: real_target, deref_mut_: deref_mut }; + if let Some(did) = target.def_id(cache) { + if let Some(type_did) = impl_.inner_impl().for_.def_id(cache) { + // `impl Deref<Target = S> for S` + if did == type_did || !derefs.insert(did) { + // Avoid infinite cycles + return; + } + } + render_assoc_items_inner(w, cx, container_item, did, what, derefs); + } else if let Some(prim) = target.primitive_type() { + if let Some(&did) = cache.primitive_locations.get(&prim) { + render_assoc_items_inner(w, cx, container_item, did, what, derefs); + } + } +} + +fn should_render_item(item: &clean::Item, deref_mut_: bool, tcx: TyCtxt<'_>) -> bool { + let self_type_opt = match *item.kind { + clean::MethodItem(ref method, _) => method.decl.self_type(), + clean::TyMethodItem(ref method) => method.decl.self_type(), + _ => None, + }; + + if let Some(self_ty) = self_type_opt { + let (by_mut_ref, by_box, by_value) = match self_ty { + SelfTy::SelfBorrowed(_, mutability) + | SelfTy::SelfExplicit(clean::BorrowedRef { mutability, .. }) => { + (mutability == Mutability::Mut, false, false) + } + SelfTy::SelfExplicit(clean::Type::Path { path }) => { + (false, Some(path.def_id()) == tcx.lang_items().owned_box(), false) + } + SelfTy::SelfValue => (false, false, true), + _ => (false, false, false), + }; + + (deref_mut_ || !by_mut_ref) && !by_box && !by_value + } else { + false + } +} + +fn notable_traits_decl(decl: &clean::FnDecl, cx: &Context<'_>) -> String { + let mut out = Buffer::html(); + + if let Some((did, ty)) = decl.output.as_return().and_then(|t| Some((t.def_id(cx.cache())?, t))) + { + if let Some(impls) = cx.cache().impls.get(&did) { + for i in impls { + let impl_ = i.inner_impl(); + if !impl_.for_.without_borrowed_ref().is_same(ty.without_borrowed_ref(), cx.cache()) + { + // Two different types might have the same did, + // without actually being the same. + continue; + } + if let Some(trait_) = &impl_.trait_ { + let trait_did = trait_.def_id(); + + if cx.cache().traits.get(&trait_did).map_or(false, |t| t.is_notable) { + if out.is_empty() { + write!( + &mut out, + "<span class=\"notable\">Notable traits for {}</span>\ + <code class=\"content\">", + impl_.for_.print(cx) + ); + } + + //use the "where" class here to make it small + write!( + &mut out, + "<span class=\"where fmt-newline\">{}</span>", + impl_.print(false, cx) + ); + for it in &impl_.items { + if let clean::AssocTypeItem(ref tydef, ref _bounds) = *it.kind { + out.push_str("<span class=\"where fmt-newline\"> "); + let empty_set = FxHashSet::default(); + let src_link = + AssocItemLink::GotoSource(trait_did.into(), &empty_set); + assoc_type( + &mut out, + it, + &tydef.generics, + &[], // intentionally leaving out bounds + Some(&tydef.type_), + src_link, + 0, + cx, + ); + out.push_str(";</span>"); + } + } + } + } + } + } + } + + if !out.is_empty() { + out.insert_str( + 0, + "<span class=\"notable-traits\"><span class=\"notable-traits-tooltip\">ⓘ\ + <span class=\"notable-traits-tooltiptext\"><span class=\"docblock\">", + ); + out.push_str("</code></span></span></span></span>"); + } + + out.into_inner() +} + +#[derive(Clone, Copy, Debug)] +struct ImplRenderingParameters { + show_def_docs: bool, + show_default_items: bool, + /// Whether or not to show methods. + show_non_assoc_items: bool, + toggle_open_by_default: bool, +} + +fn render_impl( + w: &mut Buffer, + cx: &mut Context<'_>, + i: &Impl, + parent: &clean::Item, + link: AssocItemLink<'_>, + render_mode: RenderMode, + use_absolute: Option<bool>, + aliases: &[String], + rendering_params: ImplRenderingParameters, +) { + let shared = Rc::clone(&cx.shared); + let cache = &shared.cache; + let traits = &cache.traits; + let trait_ = i.trait_did().map(|did| &traits[&did]); + let mut close_tags = String::new(); + + // For trait implementations, the `interesting` output contains all methods that have doc + // comments, and the `boring` output contains all methods that do not. The distinction is + // used to allow hiding the boring methods. + // `containing_item` is used for rendering stability info. If the parent is a trait impl, + // `containing_item` will the grandparent, since trait impls can't have stability attached. + fn doc_impl_item( + boring: &mut Buffer, + interesting: &mut Buffer, + cx: &mut Context<'_>, + item: &clean::Item, + parent: &clean::Item, + containing_item: &clean::Item, + link: AssocItemLink<'_>, + render_mode: RenderMode, + is_default_item: bool, + trait_: Option<&clean::Trait>, + rendering_params: ImplRenderingParameters, + ) { + let item_type = item.type_(); + let name = item.name.as_ref().unwrap(); + + let render_method_item = rendering_params.show_non_assoc_items + && match render_mode { + RenderMode::Normal => true, + RenderMode::ForDeref { mut_: deref_mut_ } => { + should_render_item(item, deref_mut_, cx.tcx()) + } + }; + + let in_trait_class = if trait_.is_some() { " trait-impl" } else { "" }; + + let mut doc_buffer = Buffer::empty_from(boring); + let mut info_buffer = Buffer::empty_from(boring); + let mut short_documented = true; + + if render_method_item { + if !is_default_item { + if let Some(t) = trait_ { + // The trait item may have been stripped so we might not + // find any documentation or stability for it. + if let Some(it) = t.items.iter().find(|i| i.name == item.name) { + // We need the stability of the item from the trait + // because impls can't have a stability. + if item.doc_value().is_some() { + document_item_info(&mut info_buffer, cx, it, Some(parent)); + document_full(&mut doc_buffer, item, cx, HeadingOffset::H5); + short_documented = false; + } else { + // In case the item isn't documented, + // provide short documentation from the trait. + document_short( + &mut doc_buffer, + it, + cx, + link, + parent, + rendering_params.show_def_docs, + ); + } + } + } else { + document_item_info(&mut info_buffer, cx, item, Some(parent)); + if rendering_params.show_def_docs { + document_full(&mut doc_buffer, item, cx, HeadingOffset::H5); + short_documented = false; + } + } + } else { + document_short( + &mut doc_buffer, + item, + cx, + link, + parent, + rendering_params.show_def_docs, + ); + } + } + let w = if short_documented && trait_.is_some() { interesting } else { boring }; + + let toggled = !doc_buffer.is_empty(); + if toggled { + let method_toggle_class = + if item_type == ItemType::Method { " method-toggle" } else { "" }; + write!(w, "<details class=\"rustdoc-toggle{}\" open><summary>", method_toggle_class); + } + match &*item.kind { + clean::MethodItem(..) | clean::TyMethodItem(_) => { + // Only render when the method is not static or we allow static methods + if render_method_item { + let id = cx.derive_id(format!("{}.{}", item_type, name)); + let source_id = trait_ + .and_then(|trait_| { + trait_.items.iter().find(|item| { + item.name.map(|n| n.as_str().eq(name.as_str())).unwrap_or(false) + }) + }) + .map(|item| format!("{}.{}", item.type_(), name)); + write!( + w, + "<section id=\"{}\" class=\"{}{} has-srclink\">", + id, item_type, in_trait_class, + ); + render_rightside(w, cx, item, containing_item, render_mode); + if trait_.is_some() { + // Anchors are only used on trait impls. + write!(w, "<a href=\"#{}\" class=\"anchor\"></a>", id); + } + w.write_str("<h4 class=\"code-header\">"); + render_assoc_item( + w, + item, + link.anchor(source_id.as_ref().unwrap_or(&id)), + ItemType::Impl, + cx, + render_mode, + ); + w.write_str("</h4>"); + w.write_str("</section>"); + } + } + kind @ (clean::TyAssocConstItem(ty) | clean::AssocConstItem(ty, _)) => { + let source_id = format!("{}.{}", item_type, name); + let id = cx.derive_id(source_id.clone()); + write!( + w, + "<section id=\"{}\" class=\"{}{} has-srclink\">", + id, item_type, in_trait_class + ); + render_rightside(w, cx, item, containing_item, render_mode); + if trait_.is_some() { + // Anchors are only used on trait impls. + write!(w, "<a href=\"#{}\" class=\"anchor\"></a>", id); + } + w.write_str("<h4 class=\"code-header\">"); + assoc_const( + w, + item, + ty, + match kind { + clean::TyAssocConstItem(_) => None, + clean::AssocConstItem(_, default) => Some(default), + _ => unreachable!(), + }, + link.anchor(if trait_.is_some() { &source_id } else { &id }), + "", + cx, + ); + w.write_str("</h4>"); + w.write_str("</section>"); + } + clean::TyAssocTypeItem(generics, bounds) => { + let source_id = format!("{}.{}", item_type, name); + let id = cx.derive_id(source_id.clone()); + write!(w, "<section id=\"{}\" class=\"{}{}\">", id, item_type, in_trait_class); + if trait_.is_some() { + // Anchors are only used on trait impls. + write!(w, "<a href=\"#{}\" class=\"anchor\"></a>", id); + } + w.write_str("<h4 class=\"code-header\">"); + assoc_type( + w, + item, + generics, + bounds, + None, + link.anchor(if trait_.is_some() { &source_id } else { &id }), + 0, + cx, + ); + w.write_str("</h4>"); + w.write_str("</section>"); + } + clean::AssocTypeItem(tydef, _bounds) => { + let source_id = format!("{}.{}", item_type, name); + let id = cx.derive_id(source_id.clone()); + write!( + w, + "<section id=\"{}\" class=\"{}{} has-srclink\">", + id, item_type, in_trait_class + ); + if trait_.is_some() { + // Anchors are only used on trait impls. + write!(w, "<a href=\"#{}\" class=\"anchor\"></a>", id); + } + w.write_str("<h4 class=\"code-header\">"); + assoc_type( + w, + item, + &tydef.generics, + &[], // intentionally leaving out bounds + Some(tydef.item_type.as_ref().unwrap_or(&tydef.type_)), + link.anchor(if trait_.is_some() { &source_id } else { &id }), + 0, + cx, + ); + w.write_str("</h4>"); + w.write_str("</section>"); + } + clean::StrippedItem(..) => return, + _ => panic!("can't make docs for trait item with name {:?}", item.name), + } + + w.push_buffer(info_buffer); + if toggled { + w.write_str("</summary>"); + w.push_buffer(doc_buffer); + w.push_str("</details>"); + } + } + + let mut impl_items = Buffer::empty_from(w); + let mut default_impl_items = Buffer::empty_from(w); + + for trait_item in &i.inner_impl().items { + doc_impl_item( + &mut default_impl_items, + &mut impl_items, + cx, + trait_item, + if trait_.is_some() { &i.impl_item } else { parent }, + parent, + link, + render_mode, + false, + trait_.map(|t| &t.trait_), + rendering_params, + ); + } + + fn render_default_items( + boring: &mut Buffer, + interesting: &mut Buffer, + cx: &mut Context<'_>, + t: &clean::Trait, + i: &clean::Impl, + parent: &clean::Item, + containing_item: &clean::Item, + render_mode: RenderMode, + rendering_params: ImplRenderingParameters, + ) { + for trait_item in &t.items { + let n = trait_item.name; + if i.items.iter().any(|m| m.name == n) { + continue; + } + let did = i.trait_.as_ref().unwrap().def_id(); + let provided_methods = i.provided_trait_methods(cx.tcx()); + let assoc_link = AssocItemLink::GotoSource(did.into(), &provided_methods); + + doc_impl_item( + boring, + interesting, + cx, + trait_item, + parent, + containing_item, + assoc_link, + render_mode, + true, + Some(t), + rendering_params, + ); + } + } + + // If we've implemented a trait, then also emit documentation for all + // default items which weren't overridden in the implementation block. + // We don't emit documentation for default items if they appear in the + // Implementations on Foreign Types or Implementors sections. + if rendering_params.show_default_items { + if let Some(t) = trait_ { + render_default_items( + &mut default_impl_items, + &mut impl_items, + cx, + &t.trait_, + i.inner_impl(), + &i.impl_item, + parent, + render_mode, + rendering_params, + ); + } + } + if render_mode == RenderMode::Normal { + let toggled = !(impl_items.is_empty() && default_impl_items.is_empty()); + if toggled { + close_tags.insert_str(0, "</details>"); + write!( + w, + "<details class=\"rustdoc-toggle implementors-toggle\"{}>", + if rendering_params.toggle_open_by_default { " open" } else { "" } + ); + write!(w, "<summary>") + } + render_impl_summary( + w, + cx, + i, + parent, + parent, + rendering_params.show_def_docs, + use_absolute, + aliases, + ); + if toggled { + write!(w, "</summary>") + } + + if let Some(ref dox) = i.impl_item.collapsed_doc_value() { + if trait_.is_none() && i.inner_impl().items.is_empty() { + w.write_str( + "<div class=\"item-info\">\ + <div class=\"stab empty-impl\">This impl block contains no items.</div> + </div>", + ); + } + write!( + w, + "<div class=\"docblock\">{}</div>", + Markdown { + content: &*dox, + links: &i.impl_item.links(cx), + ids: &mut cx.id_map, + error_codes: cx.shared.codes, + edition: cx.shared.edition(), + playground: &cx.shared.playground, + heading_offset: HeadingOffset::H4 + } + .into_string() + ); + } + } + if !default_impl_items.is_empty() || !impl_items.is_empty() { + w.write_str("<div class=\"impl-items\">"); + w.push_buffer(default_impl_items); + w.push_buffer(impl_items); + close_tags.insert_str(0, "</div>"); + } + w.write_str(&close_tags); +} + +// Render the items that appear on the right side of methods, impls, and +// associated types. For example "1.0.0 (const: 1.39.0) · source". +fn render_rightside( + w: &mut Buffer, + cx: &Context<'_>, + item: &clean::Item, + containing_item: &clean::Item, + render_mode: RenderMode, +) { + let tcx = cx.tcx(); + + // FIXME: Once https://github.com/rust-lang/rust/issues/67792 is implemented, we can remove + // this condition. + let (const_stability, const_stable_since) = match render_mode { + RenderMode::Normal => (item.const_stability(tcx), containing_item.const_stable_since(tcx)), + RenderMode::ForDeref { .. } => (None, None), + }; + + let mut rightside = Buffer::new(); + let has_stability = render_stability_since_raw( + &mut rightside, + item.stable_since(tcx), + const_stability, + containing_item.stable_since(tcx), + const_stable_since, + ); + let mut srclink = Buffer::empty_from(w); + write_srclink(cx, item, &mut srclink); + if has_stability && !srclink.is_empty() { + rightside.write_str(" · "); + } + rightside.push_buffer(srclink); + if !rightside.is_empty() { + write!(w, "<span class=\"rightside\">{}</span>", rightside.into_inner()); + } +} + +pub(crate) fn render_impl_summary( + w: &mut Buffer, + cx: &mut Context<'_>, + i: &Impl, + parent: &clean::Item, + containing_item: &clean::Item, + show_def_docs: bool, + use_absolute: Option<bool>, + // This argument is used to reference same type with different paths to avoid duplication + // in documentation pages for trait with automatic implementations like "Send" and "Sync". + aliases: &[String], +) { + let id = + cx.derive_id(get_id_for_impl(&i.inner_impl().for_, i.inner_impl().trait_.as_ref(), cx)); + let aliases = if aliases.is_empty() { + String::new() + } else { + format!(" data-aliases=\"{}\"", aliases.join(",")) + }; + write!(w, "<section id=\"{}\" class=\"impl has-srclink\"{}>", id, aliases); + render_rightside(w, cx, &i.impl_item, containing_item, RenderMode::Normal); + write!(w, "<a href=\"#{}\" class=\"anchor\"></a>", id); + write!(w, "<h3 class=\"code-header in-band\">"); + + if let Some(use_absolute) = use_absolute { + write!(w, "{}", i.inner_impl().print(use_absolute, cx)); + if show_def_docs { + for it in &i.inner_impl().items { + if let clean::AssocTypeItem(ref tydef, ref _bounds) = *it.kind { + w.write_str("<span class=\"where fmt-newline\"> "); + assoc_type( + w, + it, + &tydef.generics, + &[], // intentionally leaving out bounds + Some(&tydef.type_), + AssocItemLink::Anchor(None), + 0, + cx, + ); + w.write_str(";</span>"); + } + } + } + } else { + write!(w, "{}", i.inner_impl().print(false, cx)); + } + write!(w, "</h3>"); + + let is_trait = i.inner_impl().trait_.is_some(); + if is_trait { + if let Some(portability) = portability(&i.impl_item, Some(parent)) { + write!(w, "<span class=\"item-info\">{}</span>", portability); + } + } + + w.write_str("</section>"); +} + +fn print_sidebar(cx: &Context<'_>, it: &clean::Item, buffer: &mut Buffer) { + if it.is_struct() + || it.is_trait() + || it.is_primitive() + || it.is_union() + || it.is_enum() + || it.is_mod() + || it.is_typedef() + { + write!( + buffer, + "<h2 class=\"location\"><a href=\"#\">{}{}</a></h2>", + match *it.kind { + clean::ModuleItem(..) => + if it.is_crate() { + "Crate " + } else { + "Module " + }, + _ => "", + }, + it.name.as_ref().unwrap() + ); + } + + buffer.write_str("<div class=\"sidebar-elems\">"); + if it.is_crate() { + write!(buffer, "<div class=\"block\"><ul>"); + if let Some(ref version) = cx.cache().crate_version { + write!(buffer, "<li class=\"version\">Version {}</li>", Escape(version)); + } + write!(buffer, "<li><a id=\"all-types\" href=\"all.html\">All Items</a></li>"); + buffer.write_str("</ul></div>"); + } + + match *it.kind { + clean::StructItem(ref s) => sidebar_struct(cx, buffer, it, s), + clean::TraitItem(ref t) => sidebar_trait(cx, buffer, it, t), + clean::PrimitiveItem(_) => sidebar_primitive(cx, buffer, it), + clean::UnionItem(ref u) => sidebar_union(cx, buffer, it, u), + clean::EnumItem(ref e) => sidebar_enum(cx, buffer, it, e), + clean::TypedefItem(_) => sidebar_typedef(cx, buffer, it), + clean::ModuleItem(ref m) => sidebar_module(buffer, &m.items), + clean::ForeignTypeItem => sidebar_foreign_type(cx, buffer, it), + _ => {} + } + + // The sidebar is designed to display sibling functions, modules and + // other miscellaneous information. since there are lots of sibling + // items (and that causes quadratic growth in large modules), + // we refactor common parts into a shared JavaScript file per module. + // still, we don't move everything into JS because we want to preserve + // as much HTML as possible in order to allow non-JS-enabled browsers + // to navigate the documentation (though slightly inefficiently). + + if !it.is_mod() { + let path: String = cx.current.iter().map(|s| s.as_str()).intersperse("::").collect(); + + write!(buffer, "<h2 class=\"location\"><a href=\"index.html\">In {}</a></h2>", path); + } + + // Closes sidebar-elems div. + buffer.write_str("</div>"); +} + +fn get_next_url(used_links: &mut FxHashSet<String>, url: String) -> String { + if used_links.insert(url.clone()) { + return url; + } + let mut add = 1; + while !used_links.insert(format!("{}-{}", url, add)) { + add += 1; + } + format!("{}-{}", url, add) +} + +struct SidebarLink { + name: Symbol, + url: String, +} + +impl fmt::Display for SidebarLink { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + write!(f, "<a href=\"#{}\">{}</a>", self.url, self.name) + } +} + +impl PartialEq for SidebarLink { + fn eq(&self, other: &Self) -> bool { + self.url == other.url + } +} + +impl Eq for SidebarLink {} + +impl PartialOrd for SidebarLink { + fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> { + Some(self.cmp(other)) + } +} + +impl Ord for SidebarLink { + fn cmp(&self, other: &Self) -> std::cmp::Ordering { + self.url.cmp(&other.url) + } +} + +fn get_methods( + i: &clean::Impl, + for_deref: bool, + used_links: &mut FxHashSet<String>, + deref_mut: bool, + tcx: TyCtxt<'_>, +) -> Vec<SidebarLink> { + i.items + .iter() + .filter_map(|item| match item.name { + Some(name) if !name.is_empty() && item.is_method() => { + if !for_deref || should_render_item(item, deref_mut, tcx) { + Some(SidebarLink { + name, + url: get_next_url(used_links, format!("{}.{}", ItemType::Method, name)), + }) + } else { + None + } + } + _ => None, + }) + .collect::<Vec<_>>() +} + +fn get_associated_constants( + i: &clean::Impl, + used_links: &mut FxHashSet<String>, +) -> Vec<SidebarLink> { + i.items + .iter() + .filter_map(|item| match item.name { + Some(name) if !name.is_empty() && item.is_associated_const() => Some(SidebarLink { + name, + url: get_next_url(used_links, format!("{}.{}", ItemType::AssocConst, name)), + }), + _ => None, + }) + .collect::<Vec<_>>() +} + +// The point is to url encode any potential character from a type with genericity. +fn small_url_encode(s: String) -> String { + let mut st = String::new(); + let mut last_match = 0; + for (idx, c) in s.char_indices() { + let escaped = match c { + '<' => "%3C", + '>' => "%3E", + ' ' => "%20", + '?' => "%3F", + '\'' => "%27", + '&' => "%26", + ',' => "%2C", + ':' => "%3A", + ';' => "%3B", + '[' => "%5B", + ']' => "%5D", + '"' => "%22", + _ => continue, + }; + + st += &s[last_match..idx]; + st += escaped; + // NOTE: we only expect single byte characters here - which is fine as long as we + // only match single byte characters + last_match = idx + 1; + } + + if last_match != 0 { + st += &s[last_match..]; + st + } else { + s + } +} + +fn sidebar_assoc_items(cx: &Context<'_>, out: &mut Buffer, it: &clean::Item) { + let did = it.item_id.expect_def_id(); + let cache = cx.cache(); + + if let Some(v) = cache.impls.get(&did) { + let mut used_links = FxHashSet::default(); + let mut id_map = IdMap::new(); + + { + let used_links_bor = &mut used_links; + let mut assoc_consts = v + .iter() + .filter(|i| i.inner_impl().trait_.is_none()) + .flat_map(|i| get_associated_constants(i.inner_impl(), used_links_bor)) + .collect::<Vec<_>>(); + if !assoc_consts.is_empty() { + // We want links' order to be reproducible so we don't use unstable sort. + assoc_consts.sort(); + + print_sidebar_block( + out, + "implementations", + "Associated Constants", + assoc_consts.iter(), + ); + } + let mut methods = v + .iter() + .filter(|i| i.inner_impl().trait_.is_none()) + .flat_map(|i| get_methods(i.inner_impl(), false, used_links_bor, false, cx.tcx())) + .collect::<Vec<_>>(); + if !methods.is_empty() { + // We want links' order to be reproducible so we don't use unstable sort. + methods.sort(); + + print_sidebar_block(out, "implementations", "Methods", methods.iter()); + } + } + + if v.iter().any(|i| i.inner_impl().trait_.is_some()) { + if let Some(impl_) = + v.iter().find(|i| i.trait_did() == cx.tcx().lang_items().deref_trait()) + { + let mut derefs = FxHashSet::default(); + derefs.insert(did); + sidebar_deref_methods(cx, out, impl_, v, &mut derefs); + } + + let format_impls = |impls: Vec<&Impl>, id_map: &mut IdMap| { + let mut links = FxHashSet::default(); + + let mut ret = impls + .iter() + .filter_map(|it| { + let trait_ = it.inner_impl().trait_.as_ref()?; + let encoded = + id_map.derive(get_id_for_impl(&it.inner_impl().for_, Some(trait_), cx)); + + let i_display = format!("{:#}", trait_.print(cx)); + let out = Escape(&i_display); + let prefix = match it.inner_impl().polarity { + ty::ImplPolarity::Positive | ty::ImplPolarity::Reservation => "", + ty::ImplPolarity::Negative => "!", + }; + let generated = format!("<a href=\"#{}\">{}{}</a>", encoded, prefix, out); + if links.insert(generated.clone()) { Some(generated) } else { None } + }) + .collect::<Vec<String>>(); + ret.sort(); + ret + }; + + let (synthetic, concrete): (Vec<&Impl>, Vec<&Impl>) = + v.iter().partition::<Vec<_>, _>(|i| i.inner_impl().kind.is_auto()); + let (blanket_impl, concrete): (Vec<&Impl>, Vec<&Impl>) = + concrete.into_iter().partition::<Vec<_>, _>(|i| i.inner_impl().kind.is_blanket()); + + let concrete_format = format_impls(concrete, &mut id_map); + let synthetic_format = format_impls(synthetic, &mut id_map); + let blanket_format = format_impls(blanket_impl, &mut id_map); + + if !concrete_format.is_empty() { + print_sidebar_block( + out, + "trait-implementations", + "Trait Implementations", + concrete_format.iter(), + ); + } + + if !synthetic_format.is_empty() { + print_sidebar_block( + out, + "synthetic-implementations", + "Auto Trait Implementations", + synthetic_format.iter(), + ); + } + + if !blanket_format.is_empty() { + print_sidebar_block( + out, + "blanket-implementations", + "Blanket Implementations", + blanket_format.iter(), + ); + } + } + } +} + +fn sidebar_deref_methods( + cx: &Context<'_>, + out: &mut Buffer, + impl_: &Impl, + v: &[Impl], + derefs: &mut FxHashSet<DefId>, +) { + let c = cx.cache(); + + debug!("found Deref: {:?}", impl_); + if let Some((target, real_target)) = + impl_.inner_impl().items.iter().find_map(|item| match *item.kind { + clean::AssocTypeItem(box ref t, _) => Some(match *t { + clean::Typedef { item_type: Some(ref type_), .. } => (type_, &t.type_), + _ => (&t.type_, &t.type_), + }), + _ => None, + }) + { + debug!("found target, real_target: {:?} {:?}", target, real_target); + if let Some(did) = target.def_id(c) { + if let Some(type_did) = impl_.inner_impl().for_.def_id(c) { + // `impl Deref<Target = S> for S` + if did == type_did || !derefs.insert(did) { + // Avoid infinite cycles + return; + } + } + } + let deref_mut = v.iter().any(|i| i.trait_did() == cx.tcx().lang_items().deref_mut_trait()); + let inner_impl = target + .def_id(c) + .or_else(|| { + target.primitive_type().and_then(|prim| c.primitive_locations.get(&prim).cloned()) + }) + .and_then(|did| c.impls.get(&did)); + if let Some(impls) = inner_impl { + debug!("found inner_impl: {:?}", impls); + let mut used_links = FxHashSet::default(); + let mut ret = impls + .iter() + .filter(|i| i.inner_impl().trait_.is_none()) + .flat_map(|i| { + get_methods(i.inner_impl(), true, &mut used_links, deref_mut, cx.tcx()) + }) + .collect::<Vec<_>>(); + if !ret.is_empty() { + let id = if let Some(target_def_id) = real_target.def_id(c) { + cx.deref_id_map.get(&target_def_id).expect("Deref section without derived id") + } else { + "deref-methods" + }; + let title = format!( + "Methods from {}<Target={}>", + Escape(&format!("{:#}", impl_.inner_impl().trait_.as_ref().unwrap().print(cx))), + Escape(&format!("{:#}", real_target.print(cx))), + ); + // We want links' order to be reproducible so we don't use unstable sort. + ret.sort(); + print_sidebar_block(out, id, &title, ret.iter()); + } + } + + // Recurse into any further impls that might exist for `target` + if let Some(target_did) = target.def_id(c) { + if let Some(target_impls) = c.impls.get(&target_did) { + if let Some(target_deref_impl) = target_impls.iter().find(|i| { + i.inner_impl() + .trait_ + .as_ref() + .map(|t| Some(t.def_id()) == cx.tcx().lang_items().deref_trait()) + .unwrap_or(false) + }) { + sidebar_deref_methods(cx, out, target_deref_impl, target_impls, derefs); + } + } + } + } +} + +fn sidebar_struct(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, s: &clean::Struct) { + let mut sidebar = Buffer::new(); + let fields = get_struct_fields_name(&s.fields); + + if !fields.is_empty() { + match s.struct_type { + CtorKind::Fictive => { + print_sidebar_block(&mut sidebar, "fields", "Fields", fields.iter()); + } + CtorKind::Fn => print_sidebar_title(&mut sidebar, "fields", "Tuple Fields"), + CtorKind::Const => {} + } + } + + sidebar_assoc_items(cx, &mut sidebar, it); + + if !sidebar.is_empty() { + write!(buf, "<section>{}</section>", sidebar.into_inner()); + } +} + +fn get_id_for_impl(for_: &clean::Type, trait_: Option<&clean::Path>, cx: &Context<'_>) -> String { + match trait_ { + Some(t) => small_url_encode(format!("impl-{:#}-for-{:#}", t.print(cx), for_.print(cx))), + None => small_url_encode(format!("impl-{:#}", for_.print(cx))), + } +} + +fn extract_for_impl_name(item: &clean::Item, cx: &Context<'_>) -> Option<(String, String)> { + match *item.kind { + clean::ItemKind::ImplItem(ref i) => { + i.trait_.as_ref().map(|trait_| { + // Alternative format produces no URLs, + // so this parameter does nothing. + (format!("{:#}", i.for_.print(cx)), get_id_for_impl(&i.for_, Some(trait_), cx)) + }) + } + _ => None, + } +} + +/// Don't call this function directly!!! Use `print_sidebar_title` or `print_sidebar_block` instead! +fn print_sidebar_title_inner(buf: &mut Buffer, id: &str, title: &str) { + write!( + buf, + "<h3 class=\"sidebar-title\">\ + <a href=\"#{}\">{}</a>\ + </h3>", + id, title + ); +} + +fn print_sidebar_title(buf: &mut Buffer, id: &str, title: &str) { + buf.push_str("<div class=\"block\">"); + print_sidebar_title_inner(buf, id, title); + buf.push_str("</div>"); +} + +fn print_sidebar_block( + buf: &mut Buffer, + id: &str, + title: &str, + items: impl Iterator<Item = impl fmt::Display>, +) { + buf.push_str("<div class=\"block\">"); + print_sidebar_title_inner(buf, id, title); + buf.push_str("<ul>"); + for item in items { + write!(buf, "<li>{}</li>", item); + } + buf.push_str("</ul></div>"); +} + +fn sidebar_trait(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, t: &clean::Trait) { + buf.write_str("<section>"); + + fn print_sidebar_section( + out: &mut Buffer, + items: &[clean::Item], + id: &str, + title: &str, + filter: impl Fn(&clean::Item) -> bool, + mapper: impl Fn(&str) -> String, + ) { + let mut items: Vec<&str> = items + .iter() + .filter_map(|m| match m.name { + Some(ref name) if filter(m) => Some(name.as_str()), + _ => None, + }) + .collect::<Vec<_>>(); + + if !items.is_empty() { + items.sort_unstable(); + print_sidebar_block(out, id, title, items.into_iter().map(mapper)); + } + } + + print_sidebar_section( + buf, + &t.items, + "required-associated-types", + "Required Associated Types", + |m| m.is_ty_associated_type(), + |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::AssocType), + ); + + print_sidebar_section( + buf, + &t.items, + "provided-associated-types", + "Provided Associated Types", + |m| m.is_associated_type(), + |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::AssocType), + ); + + print_sidebar_section( + buf, + &t.items, + "required-associated-consts", + "Required Associated Constants", + |m| m.is_ty_associated_const(), + |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::AssocConst), + ); + + print_sidebar_section( + buf, + &t.items, + "provided-associated-consts", + "Provided Associated Constants", + |m| m.is_associated_const(), + |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::AssocConst), + ); + + print_sidebar_section( + buf, + &t.items, + "required-methods", + "Required Methods", + |m| m.is_ty_method(), + |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::TyMethod), + ); + + print_sidebar_section( + buf, + &t.items, + "provided-methods", + "Provided Methods", + |m| m.is_method(), + |sym| format!("<a href=\"#{1}.{0}\">{0}</a>", sym, ItemType::Method), + ); + + if let Some(implementors) = cx.cache().implementors.get(&it.item_id.expect_def_id()) { + let mut res = implementors + .iter() + .filter(|i| !i.is_on_local_type(cx)) + .filter_map(|i| extract_for_impl_name(&i.impl_item, cx)) + .collect::<Vec<_>>(); + + if !res.is_empty() { + res.sort(); + print_sidebar_block( + buf, + "foreign-impls", + "Implementations on Foreign Types", + res.iter().map(|(name, id)| format!("<a href=\"#{}\">{}</a>", id, Escape(name))), + ); + } + } + + sidebar_assoc_items(cx, buf, it); + + print_sidebar_title(buf, "implementors", "Implementors"); + if t.is_auto(cx.tcx()) { + print_sidebar_title(buf, "synthetic-implementors", "Auto Implementors"); + } + + buf.push_str("</section>") +} + +fn sidebar_primitive(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item) { + let mut sidebar = Buffer::new(); + sidebar_assoc_items(cx, &mut sidebar, it); + + if !sidebar.is_empty() { + write!(buf, "<section>{}</section>", sidebar.into_inner()); + } +} + +fn sidebar_typedef(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item) { + let mut sidebar = Buffer::new(); + sidebar_assoc_items(cx, &mut sidebar, it); + + if !sidebar.is_empty() { + write!(buf, "<section>{}</section>", sidebar.into_inner()); + } +} + +fn get_struct_fields_name(fields: &[clean::Item]) -> Vec<String> { + let mut fields = fields + .iter() + .filter(|f| matches!(*f.kind, clean::StructFieldItem(..))) + .filter_map(|f| { + f.name.map(|name| format!("<a href=\"#structfield.{name}\">{name}</a>", name = name)) + }) + .collect::<Vec<_>>(); + fields.sort(); + fields +} + +fn sidebar_union(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, u: &clean::Union) { + let mut sidebar = Buffer::new(); + let fields = get_struct_fields_name(&u.fields); + + if !fields.is_empty() { + print_sidebar_block(&mut sidebar, "fields", "Fields", fields.iter()); + } + + sidebar_assoc_items(cx, &mut sidebar, it); + + if !sidebar.is_empty() { + write!(buf, "<section>{}</section>", sidebar.into_inner()); + } +} + +fn sidebar_enum(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, e: &clean::Enum) { + let mut sidebar = Buffer::new(); + + let mut variants = e + .variants() + .filter_map(|v| { + v.name + .as_ref() + .map(|name| format!("<a href=\"#variant.{name}\">{name}</a>", name = name)) + }) + .collect::<Vec<_>>(); + if !variants.is_empty() { + variants.sort_unstable(); + print_sidebar_block(&mut sidebar, "variants", "Variants", variants.iter()); + } + + sidebar_assoc_items(cx, &mut sidebar, it); + + if !sidebar.is_empty() { + write!(buf, "<section>{}</section>", sidebar.into_inner()); + } +} + +#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)] +enum ItemSection { + Reexports, + PrimitiveTypes, + Modules, + Macros, + Structs, + Enums, + Constants, + Statics, + Traits, + Functions, + TypeDefinitions, + Unions, + Implementations, + TypeMethods, + Methods, + StructFields, + Variants, + AssociatedTypes, + AssociatedConstants, + ForeignTypes, + Keywords, + OpaqueTypes, + AttributeMacros, + DeriveMacros, + TraitAliases, +} + +impl ItemSection { + const ALL: &'static [Self] = { + use ItemSection::*; + // NOTE: The order here affects the order in the UI. + &[ + Reexports, + PrimitiveTypes, + Modules, + Macros, + Structs, + Enums, + Constants, + Statics, + Traits, + Functions, + TypeDefinitions, + Unions, + Implementations, + TypeMethods, + Methods, + StructFields, + Variants, + AssociatedTypes, + AssociatedConstants, + ForeignTypes, + Keywords, + OpaqueTypes, + AttributeMacros, + DeriveMacros, + TraitAliases, + ] + }; + + fn id(self) -> &'static str { + match self { + Self::Reexports => "reexports", + Self::Modules => "modules", + Self::Structs => "structs", + Self::Unions => "unions", + Self::Enums => "enums", + Self::Functions => "functions", + Self::TypeDefinitions => "types", + Self::Statics => "statics", + Self::Constants => "constants", + Self::Traits => "traits", + Self::Implementations => "impls", + Self::TypeMethods => "tymethods", + Self::Methods => "methods", + Self::StructFields => "fields", + Self::Variants => "variants", + Self::Macros => "macros", + Self::PrimitiveTypes => "primitives", + Self::AssociatedTypes => "associated-types", + Self::AssociatedConstants => "associated-consts", + Self::ForeignTypes => "foreign-types", + Self::Keywords => "keywords", + Self::OpaqueTypes => "opaque-types", + Self::AttributeMacros => "attributes", + Self::DeriveMacros => "derives", + Self::TraitAliases => "trait-aliases", + } + } + + fn name(self) -> &'static str { + match self { + Self::Reexports => "Re-exports", + Self::Modules => "Modules", + Self::Structs => "Structs", + Self::Unions => "Unions", + Self::Enums => "Enums", + Self::Functions => "Functions", + Self::TypeDefinitions => "Type Definitions", + Self::Statics => "Statics", + Self::Constants => "Constants", + Self::Traits => "Traits", + Self::Implementations => "Implementations", + Self::TypeMethods => "Type Methods", + Self::Methods => "Methods", + Self::StructFields => "Struct Fields", + Self::Variants => "Variants", + Self::Macros => "Macros", + Self::PrimitiveTypes => "Primitive Types", + Self::AssociatedTypes => "Associated Types", + Self::AssociatedConstants => "Associated Constants", + Self::ForeignTypes => "Foreign Types", + Self::Keywords => "Keywords", + Self::OpaqueTypes => "Opaque Types", + Self::AttributeMacros => "Attribute Macros", + Self::DeriveMacros => "Derive Macros", + Self::TraitAliases => "Trait Aliases", + } + } +} + +fn item_ty_to_section(ty: ItemType) -> ItemSection { + match ty { + ItemType::ExternCrate | ItemType::Import => ItemSection::Reexports, + ItemType::Module => ItemSection::Modules, + ItemType::Struct => ItemSection::Structs, + ItemType::Union => ItemSection::Unions, + ItemType::Enum => ItemSection::Enums, + ItemType::Function => ItemSection::Functions, + ItemType::Typedef => ItemSection::TypeDefinitions, + ItemType::Static => ItemSection::Statics, + ItemType::Constant => ItemSection::Constants, + ItemType::Trait => ItemSection::Traits, + ItemType::Impl => ItemSection::Implementations, + ItemType::TyMethod => ItemSection::TypeMethods, + ItemType::Method => ItemSection::Methods, + ItemType::StructField => ItemSection::StructFields, + ItemType::Variant => ItemSection::Variants, + ItemType::Macro => ItemSection::Macros, + ItemType::Primitive => ItemSection::PrimitiveTypes, + ItemType::AssocType => ItemSection::AssociatedTypes, + ItemType::AssocConst => ItemSection::AssociatedConstants, + ItemType::ForeignType => ItemSection::ForeignTypes, + ItemType::Keyword => ItemSection::Keywords, + ItemType::OpaqueTy => ItemSection::OpaqueTypes, + ItemType::ProcAttribute => ItemSection::AttributeMacros, + ItemType::ProcDerive => ItemSection::DeriveMacros, + ItemType::TraitAlias => ItemSection::TraitAliases, + } +} + +fn sidebar_module(buf: &mut Buffer, items: &[clean::Item]) { + use std::fmt::Write as _; + + let mut sidebar = String::new(); + + let item_sections_in_use: FxHashSet<_> = items + .iter() + .filter(|it| { + !it.is_stripped() + && it + .name + .or_else(|| { + if let clean::ImportItem(ref i) = *it.kind && + let clean::ImportKind::Simple(s) = i.kind { Some(s) } else { None } + }) + .is_some() + }) + .map(|it| item_ty_to_section(it.type_())) + .collect(); + for &sec in ItemSection::ALL.iter().filter(|sec| item_sections_in_use.contains(sec)) { + let _ = write!(sidebar, "<li><a href=\"#{}\">{}</a></li>", sec.id(), sec.name()); + } + + if !sidebar.is_empty() { + write!( + buf, + "<section>\ + <div class=\"block\">\ + <ul>{}</ul>\ + </div>\ + </section>", + sidebar + ); + } +} + +fn sidebar_foreign_type(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item) { + let mut sidebar = Buffer::new(); + sidebar_assoc_items(cx, &mut sidebar, it); + + if !sidebar.is_empty() { + write!(buf, "<section>{}</section>", sidebar.into_inner()); + } +} + +pub(crate) const BASIC_KEYWORDS: &str = "rust, rustlang, rust-lang"; + +/// Returns a list of all paths used in the type. +/// This is used to help deduplicate imported impls +/// for reexported types. If any of the contained +/// types are re-exported, we don't use the corresponding +/// entry from the js file, as inlining will have already +/// picked up the impl +fn collect_paths_for_type(first_ty: clean::Type, cache: &Cache) -> Vec<String> { + let mut out = Vec::new(); + let mut visited = FxHashSet::default(); + let mut work = VecDeque::new(); + + let mut process_path = |did: DefId| { + let get_extern = || cache.external_paths.get(&did).map(|s| s.0.clone()); + let fqp = cache.exact_paths.get(&did).cloned().or_else(get_extern); + + if let Some(path) = fqp { + out.push(join_with_double_colon(&path)); + } + }; + + work.push_back(first_ty); + + while let Some(ty) = work.pop_front() { + if !visited.insert(ty.clone()) { + continue; + } + + match ty { + clean::Type::Path { path } => process_path(path.def_id()), + clean::Type::Tuple(tys) => { + work.extend(tys.into_iter()); + } + clean::Type::Slice(ty) => { + work.push_back(*ty); + } + clean::Type::Array(ty, _) => { + work.push_back(*ty); + } + clean::Type::RawPointer(_, ty) => { + work.push_back(*ty); + } + clean::Type::BorrowedRef { type_, .. } => { + work.push_back(*type_); + } + clean::Type::QPath { self_type, trait_, .. } => { + work.push_back(*self_type); + process_path(trait_.def_id()); + } + _ => {} + } + } + out +} + +const MAX_FULL_EXAMPLES: usize = 5; +const NUM_VISIBLE_LINES: usize = 10; + +/// Generates the HTML for example call locations generated via the --scrape-examples flag. +fn render_call_locations(w: &mut Buffer, cx: &mut Context<'_>, item: &clean::Item) { + let tcx = cx.tcx(); + let def_id = item.item_id.expect_def_id(); + let key = tcx.def_path_hash(def_id); + let Some(call_locations) = cx.shared.call_locations.get(&key) else { return }; + + // Generate a unique ID so users can link to this section for a given method + let id = cx.id_map.derive("scraped-examples"); + write!( + w, + "<div class=\"docblock scraped-example-list\">\ + <span></span>\ + <h5 id=\"{id}\">\ + <a href=\"#{id}\">Examples found in repository</a>\ + <a class=\"scrape-help\" href=\"{root_path}scrape-examples-help.html\">?</a>\ + </h5>", + root_path = cx.root_path(), + id = id + ); + + // Create a URL to a particular location in a reverse-dependency's source file + let link_to_loc = |call_data: &CallData, loc: &CallLocation| -> (String, String) { + let (line_lo, line_hi) = loc.call_expr.line_span; + let (anchor, title) = if line_lo == line_hi { + ((line_lo + 1).to_string(), format!("line {}", line_lo + 1)) + } else { + ( + format!("{}-{}", line_lo + 1, line_hi + 1), + format!("lines {}-{}", line_lo + 1, line_hi + 1), + ) + }; + let url = format!("{}{}#{}", cx.root_path(), call_data.url, anchor); + (url, title) + }; + + // Generate the HTML for a single example, being the title and code block + let write_example = |w: &mut Buffer, (path, call_data): (&PathBuf, &CallData)| -> bool { + let contents = match fs::read_to_string(&path) { + Ok(contents) => contents, + Err(err) => { + let span = item.span(tcx).inner(); + tcx.sess + .span_err(span, &format!("failed to read file {}: {}", path.display(), err)); + return false; + } + }; + + // To reduce file sizes, we only want to embed the source code needed to understand the example, not + // the entire file. So we find the smallest byte range that covers all items enclosing examples. + assert!(!call_data.locations.is_empty()); + let min_loc = + call_data.locations.iter().min_by_key(|loc| loc.enclosing_item.byte_span.0).unwrap(); + let byte_min = min_loc.enclosing_item.byte_span.0; + let line_min = min_loc.enclosing_item.line_span.0; + let max_loc = + call_data.locations.iter().max_by_key(|loc| loc.enclosing_item.byte_span.1).unwrap(); + let byte_max = max_loc.enclosing_item.byte_span.1; + let line_max = max_loc.enclosing_item.line_span.1; + + // The output code is limited to that byte range. + let contents_subset = &contents[(byte_min as usize)..(byte_max as usize)]; + + // The call locations need to be updated to reflect that the size of the program has changed. + // Specifically, the ranges are all subtracted by `byte_min` since that's the new zero point. + let (mut byte_ranges, line_ranges): (Vec<_>, Vec<_>) = call_data + .locations + .iter() + .map(|loc| { + let (byte_lo, byte_hi) = loc.call_ident.byte_span; + let (line_lo, line_hi) = loc.call_expr.line_span; + let byte_range = (byte_lo - byte_min, byte_hi - byte_min); + + let line_range = (line_lo - line_min, line_hi - line_min); + let (line_url, line_title) = link_to_loc(call_data, loc); + + (byte_range, (line_range, line_url, line_title)) + }) + .unzip(); + + let (_, init_url, init_title) = &line_ranges[0]; + let needs_expansion = line_max - line_min > NUM_VISIBLE_LINES; + let locations_encoded = serde_json::to_string(&line_ranges).unwrap(); + + write!( + w, + "<div class=\"scraped-example {expanded_cls}\" data-locs=\"{locations}\">\ + <div class=\"scraped-example-title\">\ + {name} (<a href=\"{url}\">{title}</a>)\ + </div>\ + <div class=\"code-wrapper\">", + expanded_cls = if needs_expansion { "" } else { "expanded" }, + name = call_data.display_name, + url = init_url, + title = init_title, + // The locations are encoded as a data attribute, so they can be read + // later by the JS for interactions. + locations = Escape(&locations_encoded) + ); + + if line_ranges.len() > 1 { + write!(w, r#"<span class="prev">≺</span> <span class="next">≻</span>"#); + } + + if needs_expansion { + write!(w, r#"<span class="expand">↕</span>"#); + } + + // Look for the example file in the source map if it exists, otherwise return a dummy span + let file_span = (|| { + let source_map = tcx.sess.source_map(); + let crate_src = tcx.sess.local_crate_source_file.as_ref()?; + let abs_crate_src = crate_src.canonicalize().ok()?; + let crate_root = abs_crate_src.parent()?.parent()?; + let rel_path = path.strip_prefix(crate_root).ok()?; + let files = source_map.files(); + let file = files.iter().find(|file| match &file.name { + FileName::Real(RealFileName::LocalPath(other_path)) => rel_path == other_path, + _ => false, + })?; + Some(rustc_span::Span::with_root_ctxt( + file.start_pos + BytePos(byte_min), + file.start_pos + BytePos(byte_max), + )) + })() + .unwrap_or(rustc_span::DUMMY_SP); + + // The root path is the inverse of Context::current + let root_path = vec!["../"; cx.current.len() - 1].join(""); + + let mut decoration_info = FxHashMap::default(); + decoration_info.insert("highlight focus", vec![byte_ranges.remove(0)]); + decoration_info.insert("highlight", byte_ranges); + + sources::print_src( + w, + contents_subset, + call_data.edition, + file_span, + cx, + &root_path, + Some(highlight::DecorationInfo(decoration_info)), + sources::SourceContext::Embedded { offset: line_min }, + ); + write!(w, "</div></div>"); + + true + }; + + // The call locations are output in sequence, so that sequence needs to be determined. + // Ideally the most "relevant" examples would be shown first, but there's no general algorithm + // for determining relevance. Instead, we prefer the smallest examples being likely the easiest to + // understand at a glance. + let ordered_locations = { + let sort_criterion = |(_, call_data): &(_, &CallData)| { + // Use the first location because that's what the user will see initially + let (lo, hi) = call_data.locations[0].enclosing_item.byte_span; + hi - lo + }; + + let mut locs = call_locations.iter().collect::<Vec<_>>(); + locs.sort_by_key(sort_criterion); + locs + }; + + let mut it = ordered_locations.into_iter().peekable(); + + // An example may fail to write if its source can't be read for some reason, so this method + // continues iterating until a write succeeds + let write_and_skip_failure = |w: &mut Buffer, it: &mut Peekable<_>| { + while let Some(example) = it.next() { + if write_example(&mut *w, example) { + break; + } + } + }; + + // Write just one example that's visible by default in the method's description. + write_and_skip_failure(w, &mut it); + + // Then add the remaining examples in a hidden section. + if it.peek().is_some() { + write!( + w, + "<details class=\"rustdoc-toggle more-examples-toggle\">\ + <summary class=\"hideme\">\ + <span>More examples</span>\ + </summary>\ + <div class=\"hide-more\">Hide additional examples</div>\ + <div class=\"more-scraped-examples\">\ + <div class=\"toggle-line\"><div class=\"toggle-line-inner\"></div></div>\ + <div class=\"more-scraped-examples-inner\">" + ); + + // Only generate inline code for MAX_FULL_EXAMPLES number of examples. Otherwise we could + // make the page arbitrarily huge! + for _ in 0..MAX_FULL_EXAMPLES { + write_and_skip_failure(w, &mut it); + } + + // For the remaining examples, generate a <ul> containing links to the source files. + if it.peek().is_some() { + write!(w, r#"<div class="example-links">Additional examples can be found in:<br><ul>"#); + it.for_each(|(_, call_data)| { + let (url, _) = link_to_loc(call_data, &call_data.locations[0]); + write!( + w, + r#"<li><a href="{url}">{name}</a></li>"#, + url = url, + name = call_data.display_name + ); + }); + write!(w, "</ul></div>"); + } + + write!(w, "</div></div></details>"); + } + + write!(w, "</div>"); +} |