src/librustdoc/html/render/context.rs

   1 use std::cell::RefCell;
   2 use std::collections::BTreeMap;
   3 use std::io;
   4 use std::path::{Path, PathBuf};
   5 use std::rc::Rc;
   6 use std::sync::mpsc::{channel, Receiver};
   7
   8 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
   9 use rustc_hir::def_id::LOCAL_CRATE;
  10 use rustc_middle::ty::TyCtxt;
  11 use rustc_session::Session;
  12 use rustc_span::edition::Edition;
  13 use rustc_span::source_map::FileName;
  14 use rustc_span::symbol::sym;
  15
  16 use super::cache::{build_index, ExternalLocation};
  17 use super::print_item::{full_path, item_path, print_item};
  18 use super::write_shared::write_shared;
  19 use super::{print_sidebar, settings, AllTypes, NameDoc, StylePath, BASIC_KEYWORDS};
  20
  21 use crate::clean;
  22 use crate::clean::ExternalCrate;
  23 use crate::config::RenderOptions;
  24 use crate::docfs::{DocFS, PathError};
  25 use crate::error::Error;
  26 use crate::formats::cache::Cache;
  27 use crate::formats::item_type::ItemType;
  28 use crate::formats::FormatRenderer;
  29 use crate::html::escape::Escape;
  30 use crate::html::format::Buffer;
  31 use crate::html::markdown::{self, plain_text_summary, ErrorCodes, IdMap};
  32 use crate::html::{layout, sources};
  33
  34 /// Major driving force in all rustdoc rendering. This contains information
  35 /// about where in the tree-like hierarchy rendering is occurring and controls
  36 /// how the current page is being rendered.
  37 ///
  38 /// It is intended that this context is a lightweight object which can be fairly
  39 /// easily cloned because it is cloned per work-job (about once per item in the
  40 /// rustdoc tree).
  41 crate struct Context<'tcx> {
  42     /// Current hierarchy of components leading down to what's currently being
  43     /// rendered
  44     pub(crate) current: Vec<String>,
  45     /// The current destination folder of where HTML artifacts should be placed.
  46     /// This changes as the context descends into the module hierarchy.
  47     pub(super) dst: PathBuf,
  48     /// A flag, which when `true`, will render pages which redirect to the
  49     /// real location of an item. This is used to allow external links to
  50     /// publicly reused items to redirect to the right location.
  51     pub(super) render_redirect_pages: bool,
  52     /// The map used to ensure all generated 'id=' attributes are unique.
  53     pub(super) id_map: RefCell<IdMap>,
  54     /// Shared mutable state.
  55     ///
  56     /// Issue for improving the situation: [#82381][]
  57     ///
  58     /// [#82381]: https://github.com/rust-lang/rust/issues/82381
  59     pub(super) shared: Rc<SharedContext<'tcx>>,
  60     /// The [`Cache`] used during rendering.
  61     ///
  62     /// Ideally the cache would be in [`SharedContext`], but it's mutated
  63     /// between when the `SharedContext` is created and when `Context`
  64     /// is created, so more refactoring would be needed.
  65     ///
  66     /// It's immutable once in `Context`, so it's not as bad that it's not in
  67     /// `SharedContext`.
  68     // FIXME: move `cache` to `SharedContext`
  69     pub(super) cache: Rc<Cache>,
  70 }
  71
  72 // `Context` is cloned a lot, so we don't want the size to grow unexpectedly.
  73 #[cfg(target_arch = "x86_64")]
  74 rustc_data_structures::static_assert_size!(Context<'_>, 112);
  75
  76 /// Shared mutable state used in [`Context`] and elsewhere.
  77 crate struct SharedContext<'tcx> {
  78     crate tcx: TyCtxt<'tcx>,
  79     /// The path to the crate root source minus the file name.
  80     /// Used for simplifying paths to the highlighted source code files.
  81     crate src_root: PathBuf,
  82     /// This describes the layout of each page, and is not modified after
  83     /// creation of the context (contains info like the favicon and added html).
  84     crate layout: layout::Layout,
  85     /// This flag indicates whether `[src]` links should be generated or not. If
  86     /// the source files are present in the html rendering, then this will be
  87     /// `true`.
  88     crate include_sources: bool,
  89     /// The local file sources we've emitted and their respective url-paths.
  90     crate local_sources: FxHashMap<PathBuf, String>,
  91     /// Show the memory layout of types in the docs.
  92     pub(super) show_type_layout: bool,
  93     /// Whether the collapsed pass ran
  94     collapsed: bool,
  95     /// The base-URL of the issue tracker for when an item has been tagged with
  96     /// an issue number.
  97     pub(super) issue_tracker_base_url: Option<String>,
  98     /// The directories that have already been created in this doc run. Used to reduce the number
  99     /// of spurious `create_dir_all` calls.
 100     created_dirs: RefCell<FxHashSet<PathBuf>>,
 101     /// This flag indicates whether listings of modules (in the side bar and documentation itself)
 102     /// should be ordered alphabetically or in order of appearance (in the source code).
 103     pub(super) sort_modules_alphabetically: bool,
 104     /// Additional CSS files to be added to the generated docs.
 105     crate style_files: Vec<StylePath>,
 106     /// Suffix to be added on resource files (if suffix is "-v2" then "light.css" becomes
 107     /// "light-v2.css").
 108     crate resource_suffix: String,
 109     /// Optional path string to be used to load static files on output pages. If not set, uses
 110     /// combinations of `../` to reach the documentation root.
 111     crate static_root_path: Option<String>,
 112     /// The fs handle we are working with.
 113     crate fs: DocFS,
 114     pub(super) codes: ErrorCodes,
 115     pub(super) playground: Option<markdown::Playground>,
 116     all: RefCell<AllTypes>,
 117     /// Storage for the errors produced while generating documentation so they
 118     /// can be printed together at the end.
 119     errors: Receiver<String>,
 120     /// `None` by default, depends on the `generate-redirect-map` option flag. If this field is set
 121     /// to `Some(...)`, it'll store redirections and then generate a JSON file at the top level of
 122     /// the crate.
 123     redirections: Option<RefCell<FxHashMap<String, String>>>,
 124 }
 125
 126 impl SharedContext<'_> {
 127     crate fn ensure_dir(&self, dst: &Path) -> Result<(), Error> {
 128         let mut dirs = self.created_dirs.borrow_mut();
 129         if !dirs.contains(dst) {
 130             try_err!(self.fs.create_dir_all(dst), dst);
 131             dirs.insert(dst.to_path_buf());
 132         }
 133
 134         Ok(())
 135     }
 136
 137     /// Returns the `collapsed_doc_value` of the given item if this is the main crate, otherwise
 138     /// returns the `doc_value`.
 139     crate fn maybe_collapsed_doc_value<'a>(&self, item: &'a clean::Item) -> Option<String> {
 140         if self.collapsed { item.collapsed_doc_value() } else { item.doc_value() }
 141     }
 142
 143     crate fn edition(&self) -> Edition {
 144         self.tcx.sess.edition()
 145     }
 146 }
 147
 148 impl<'tcx> Context<'tcx> {
 149     pub(crate) fn tcx(&self) -> TyCtxt<'tcx> {
 150         self.shared.tcx
 151     }
 152
 153     pub(crate) fn cache(&self) -> &Cache {
 154         &self.cache
 155     }
 156
 157     pub(super) fn sess(&self) -> &'tcx Session {
 158         &self.shared.tcx.sess
 159     }
 160
 161     pub(super) fn derive_id(&self, id: String) -> String {
 162         let mut map = self.id_map.borrow_mut();
 163         map.derive(id)
 164     }
 165
 166     /// String representation of how to get back to the root path of the 'doc/'
 167     /// folder in terms of a relative URL.
 168     pub(super) fn root_path(&self) -> String {
 169         "../".repeat(self.current.len())
 170     }
 171
 172     fn render_item(&self, it: &clean::Item, is_module: bool) -> String {
 173         let mut title = String::new();
 174         if !is_module {
 175             title.push_str(&it.name.unwrap().as_str());
 176         }
 177         if !it.is_primitive() && !it.is_keyword() {
 178             if !is_module {
 179                 title.push_str(" in ");
 180             }
 181             // No need to include the namespace for primitive types and keywords
 182             title.push_str(&self.current.join("::"));
 183         };
 184         title.push_str(" - Rust");
 185         let tyname = it.type_();
 186         let desc = it.doc_value().as_ref().map(|doc| plain_text_summary(&doc));
 187         let desc = if let Some(desc) = desc {
 188             desc
 189         } else if it.is_crate() {
 190             format!("API documentation for the Rust `{}` crate.", self.shared.layout.krate)
 191         } else {
 192             format!(
 193                 "API documentation for the Rust `{}` {} in crate `{}`.",
 194                 it.name.as_ref().unwrap(),
 195                 tyname,
 196                 self.shared.layout.krate
 197             )
 198         };
 199         let keywords = make_item_keywords(it);
 200         let name;
 201         let tyname_s = if it.is_crate() {
 202             name = format!("{} crate", tyname);
 203             name.as_str()
 204         } else {
 205             tyname.as_str()
 206         };
 207         let page = layout::Page {
 208             css_class: tyname_s,
 209             root_path: &self.root_path(),
 210             static_root_path: self.shared.static_root_path.as_deref(),
 211             title: &title,
 212             description: &desc,
 213             keywords: &keywords,
 214             resource_suffix: &self.shared.resource_suffix,
 215             extra_scripts: &[],
 216             static_extra_scripts: &[],
 217         };
 218
 219         if !self.render_redirect_pages {
 220             layout::render(
 221                 &self.shared.layout,
 222                 &page,
 223                 |buf: &mut _| print_sidebar(self, it, buf),
 224                 |buf: &mut _| print_item(self, it, buf, &page),
 225                 &self.shared.style_files,
 226             )
 227         } else {
 228             if let Some(&(ref names, ty)) = self.cache.paths.get(&it.def_id.expect_real()) {
 229                 let mut path = String::new();
 230                 for name in &names[..names.len() - 1] {
 231                     path.push_str(name);
 232                     path.push('/');
 233                 }
 234                 path.push_str(&item_path(ty, names.last().unwrap()));
 235                 match self.shared.redirections {
 236                     Some(ref redirections) => {
 237                         let mut current_path = String::new();
 238                         for name in &self.current {
 239                             current_path.push_str(name);
 240                             current_path.push('/');
 241                         }
 242                         current_path.push_str(&item_path(ty, names.last().unwrap()));
 243                         redirections.borrow_mut().insert(current_path, path);
 244                     }
 245                     None => return layout::redirect(&format!("{}{}", self.root_path(), path)),
 246                 }
 247             }
 248             String::new()
 249         }
 250     }
 251
 252     /// Construct a map of items shown in the sidebar to a plain-text summary of their docs.
 253     fn build_sidebar_items(&self, m: &clean::Module) -> BTreeMap<String, Vec<NameDoc>> {
 254         // BTreeMap instead of HashMap to get a sorted output
 255         let mut map: BTreeMap<_, Vec<_>> = BTreeMap::new();
 256         for item in &m.items {
 257             if item.is_stripped() {
 258                 continue;
 259             }
 260
 261             let short = item.type_();
 262             let myname = match item.name {
 263                 None => continue,
 264                 Some(ref s) => s.to_string(),
 265             };
 266             let short = short.to_string();
 267             map.entry(short).or_default().push((
 268                 myname,
 269                 Some(item.doc_value().map_or_else(String::new, |s| plain_text_summary(&s))),
 270             ));
 271         }
 272
 273         if self.shared.sort_modules_alphabetically {
 274             for items in map.values_mut() {
 275                 items.sort();
 276             }
 277         }
 278         map
 279     }
 280
 281     /// Generates a url appropriate for an `href` attribute back to the source of
 282     /// this item.
 283     ///
 284     /// The url generated, when clicked, will redirect the browser back to the
 285     /// original source code.
 286     ///
 287     /// If `None` is returned, then a source link couldn't be generated. This
 288     /// may happen, for example, with externally inlined items where the source
 289     /// of their crate documentation isn't known.
 290     pub(super) fn src_href(&self, item: &clean::Item) -> Option<String> {
 291         if item.span(self.tcx()).is_dummy() {
 292             return None;
 293         }
 294         let mut root = self.root_path();
 295         let mut path = String::new();
 296         let cnum = item.span(self.tcx()).cnum(self.sess());
 297
 298         // We can safely ignore synthetic `SourceFile`s.
 299         let file = match item.span(self.tcx()).filename(self.sess()) {
 300             FileName::Real(ref path) => path.local_path_if_available().to_path_buf(),
 301             _ => return None,
 302         };
 303         let file = &file;
 304
 305         let symbol;
 306         let (krate, path) = if cnum == LOCAL_CRATE {
 307             if let Some(path) = self.shared.local_sources.get(file) {
 308                 (self.shared.layout.krate.as_str(), path)
 309             } else {
 310                 return None;
 311             }
 312         } else {
 313             let (krate, src_root) = match *self.cache.extern_locations.get(&cnum)? {
 314                 ExternalLocation::Local => {
 315                     let e = ExternalCrate { crate_num: cnum };
 316                     (e.name(self.tcx()), e.src_root(self.tcx()))
 317                 }
 318                 ExternalLocation::Remote(ref s) => {
 319                     root = s.to_string();
 320                     let e = ExternalCrate { crate_num: cnum };
 321                     (e.name(self.tcx()), e.src_root(self.tcx()))
 322                 }
 323                 ExternalLocation::Unknown => return None,
 324             };
 325
 326             sources::clean_path(&src_root, file, false, |component| {
 327                 path.push_str(&component.to_string_lossy());
 328                 path.push('/');
 329             });
 330             let mut fname = file.file_name().expect("source has no filename").to_os_string();
 331             fname.push(".html");
 332             path.push_str(&fname.to_string_lossy());
 333             symbol = krate.as_str();
 334             (&*symbol, &path)
 335         };
 336
 337         let loline = item.span(self.tcx()).lo(self.sess()).line;
 338         let hiline = item.span(self.tcx()).hi(self.sess()).line;
 339         let lines =
 340             if loline == hiline { loline.to_string() } else { format!("{}-{}", loline, hiline) };
 341         Some(format!(
 342             "{root}src/{krate}/{path}#{lines}",
 343             root = Escape(&root),
 344             krate = krate,
 345             path = path,
 346             lines = lines
 347         ))
 348     }
 349 }
 350
 351 /// Generates the documentation for `crate` into the directory `dst`
 352 impl<'tcx> FormatRenderer<'tcx> for Context<'tcx> {
 353     fn descr() -> &'static str {
 354         "html"
 355     }
 356
 357     const RUN_ON_MODULE: bool = true;
 358
 359     fn init(
 360         mut krate: clean::Crate,
 361         options: RenderOptions,
 362         mut cache: Cache,
 363         tcx: TyCtxt<'tcx>,
 364     ) -> Result<(Self, clean::Crate), Error> {
 365         // need to save a copy of the options for rendering the index page
 366         let md_opts = options.clone();
 367         let emit_crate = options.should_emit_crate();
 368         let RenderOptions {
 369             output,
 370             external_html,
 371             id_map,
 372             playground_url,
 373             sort_modules_alphabetically,
 374             themes: style_files,
 375             default_settings,
 376             extension_css,
 377             resource_suffix,
 378             static_root_path,
 379             generate_search_filter,
 380             unstable_features,
 381             generate_redirect_map,
 382             show_type_layout,
 383             ..
 384         } = options;
 385
 386         let src_root = match krate.src {
 387             FileName::Real(ref p) => match p.local_path_if_available().parent() {
 388                 Some(p) => p.to_path_buf(),
 389                 None => PathBuf::new(),
 390             },
 391             _ => PathBuf::new(),
 392         };
 393         // If user passed in `--playground-url` arg, we fill in crate name here
 394         let mut playground = None;
 395         if let Some(url) = playground_url {
 396             playground =
 397                 Some(markdown::Playground { crate_name: Some(krate.name.to_string()), url });
 398         }
 399         let mut layout = layout::Layout {
 400             logo: String::new(),
 401             favicon: String::new(),
 402             external_html,
 403             default_settings,
 404             krate: krate.name.to_string(),
 405             css_file_extension: extension_css,
 406             generate_search_filter,
 407         };
 408         let mut issue_tracker_base_url = None;
 409         let mut include_sources = true;
 410
 411         // Crawl the crate attributes looking for attributes which control how we're
 412         // going to emit HTML
 413         for attr in krate.module.attrs.lists(sym::doc) {
 414             match (attr.name_or_empty(), attr.value_str()) {
 415                 (sym::html_favicon_url, Some(s)) => {
 416                     layout.favicon = s.to_string();
 417                 }
 418                 (sym::html_logo_url, Some(s)) => {
 419                     layout.logo = s.to_string();
 420                 }
 421                 (sym::html_playground_url, Some(s)) => {
 422                     playground = Some(markdown::Playground {
 423                         crate_name: Some(krate.name.to_string()),
 424                         url: s.to_string(),
 425                     });
 426                 }
 427                 (sym::issue_tracker_base_url, Some(s)) => {
 428                     issue_tracker_base_url = Some(s.to_string());
 429                 }
 430                 (sym::html_no_source, None) if attr.is_word() => {
 431                     include_sources = false;
 432                 }
 433                 _ => {}
 434             }
 435         }
 436         let (sender, receiver) = channel();
 437         let mut scx = SharedContext {
 438             tcx,
 439             collapsed: krate.collapsed,
 440             src_root,
 441             include_sources,
 442             local_sources: Default::default(),
 443             issue_tracker_base_url,
 444             layout,
 445             created_dirs: Default::default(),
 446             sort_modules_alphabetically,
 447             style_files,
 448             resource_suffix,
 449             static_root_path,
 450             fs: DocFS::new(sender),
 451             codes: ErrorCodes::from(unstable_features.is_nightly_build()),
 452             playground,
 453             all: RefCell::new(AllTypes::new()),
 454             errors: receiver,
 455             redirections: if generate_redirect_map { Some(Default::default()) } else { None },
 456             show_type_layout,
 457         };
 458
 459         // Add the default themes to the `Vec` of stylepaths
 460         //
 461         // Note that these must be added before `sources::render` is called
 462         // so that the resulting source pages are styled
 463         //
 464         // `light.css` is not disabled because it is the stylesheet that stays loaded
 465         // by the browser as the theme stylesheet. The theme system (hackily) works by
 466         // changing the href to this stylesheet. All other themes are disabled to
 467         // prevent rule conflicts
 468         scx.style_files.push(StylePath { path: PathBuf::from("light.css"), disabled: false });
 469         scx.style_files.push(StylePath { path: PathBuf::from("dark.css"), disabled: true });
 470         scx.style_files.push(StylePath { path: PathBuf::from("ayu.css"), disabled: true });
 471
 472         let dst = output;
 473         scx.ensure_dir(&dst)?;
 474         if emit_crate {
 475             krate = sources::render(&dst, &mut scx, krate)?;
 476         }
 477
 478         // Build our search index
 479         let index = build_index(&krate, &mut cache, tcx);
 480
 481         let mut cx = Context {
 482             current: Vec::new(),
 483             dst,
 484             render_redirect_pages: false,
 485             id_map: RefCell::new(id_map),
 486             shared: Rc::new(scx),
 487             cache: Rc::new(cache),
 488         };
 489
 490         // Write shared runs within a flock; disable thread dispatching of IO temporarily.
 491         Rc::get_mut(&mut cx.shared).unwrap().fs.set_sync_only(true);
 492         write_shared(&cx, &krate, index, &md_opts)?;
 493         Rc::get_mut(&mut cx.shared).unwrap().fs.set_sync_only(false);
 494         Ok((cx, krate))
 495     }
 496
 497     fn make_child_renderer(&self) -> Self {
 498         Self {
 499             current: self.current.clone(),
 500             dst: self.dst.clone(),
 501             render_redirect_pages: self.render_redirect_pages,
 502             id_map: RefCell::new(IdMap::new()),
 503             shared: Rc::clone(&self.shared),
 504             cache: Rc::clone(&self.cache),
 505         }
 506     }
 507
 508     fn after_krate(&mut self) -> Result<(), Error> {
 509         let crate_name = self.tcx().crate_name(LOCAL_CRATE);
 510         let final_file = self.dst.join(&*crate_name.as_str()).join("all.html");
 511         let settings_file = self.dst.join("settings.html");
 512
 513         let mut root_path = self.dst.to_str().expect("invalid path").to_owned();
 514         if !root_path.ends_with('/') {
 515             root_path.push('/');
 516         }
 517         let mut page = layout::Page {
 518             title: "List of all items in this crate",
 519             css_class: "mod",
 520             root_path: "../",
 521             static_root_path: self.shared.static_root_path.as_deref(),
 522             description: "List of all items in this crate",
 523             keywords: BASIC_KEYWORDS,
 524             resource_suffix: &self.shared.resource_suffix,
 525             extra_scripts: &[],
 526             static_extra_scripts: &[],
 527         };
 528         let sidebar = if let Some(ref version) = self.cache.crate_version {
 529             format!(
 530                 "<h2 class=\"location\">Crate {}</h2>\
 531                      <div class=\"block version\">\
 532                          <p>Version {}</p>\
 533                      </div>\
 534                      <a id=\"all-types\" href=\"index.html\"><p>Back to index</p></a>",
 535                 crate_name,
 536                 Escape(version),
 537             )
 538         } else {
 539             String::new()
 540         };
 541         let all = self.shared.all.replace(AllTypes::new());
 542         let v = layout::render(
 543             &self.shared.layout,
 544             &page,
 545             sidebar,
 546             |buf: &mut Buffer| all.print(buf),
 547             &self.shared.style_files,
 548         );
 549         self.shared.fs.write(final_file, v.as_bytes())?;
 550
 551         // Generating settings page.
 552         page.title = "Rustdoc settings";
 553         page.description = "Settings of Rustdoc";
 554         page.root_path = "./";
 555
 556         let mut style_files = self.shared.style_files.clone();
 557         let sidebar = "<h2 class=\"location\">Settings</h2><div class=\"sidebar-elems\"></div>";
 558         style_files.push(StylePath { path: PathBuf::from("settings.css"), disabled: false });
 559         let v = layout::render(
 560             &self.shared.layout,
 561             &page,
 562             sidebar,
 563             settings(
 564                 self.shared.static_root_path.as_deref().unwrap_or("./"),
 565                 &self.shared.resource_suffix,
 566                 &self.shared.style_files,
 567             )?,
 568             &style_files,
 569         );
 570         self.shared.fs.write(&settings_file, v.as_bytes())?;
 571         if let Some(ref redirections) = self.shared.redirections {
 572             if !redirections.borrow().is_empty() {
 573                 let redirect_map_path =
 574                     self.dst.join(&*crate_name.as_str()).join("redirect-map.json");
 575                 let paths = serde_json::to_string(&*redirections.borrow()).unwrap();
 576                 self.shared.ensure_dir(&self.dst.join(&*crate_name.as_str()))?;
 577                 self.shared.fs.write(&redirect_map_path, paths.as_bytes())?;
 578             }
 579         }
 580
 581         // Flush pending errors.
 582         Rc::get_mut(&mut self.shared).unwrap().fs.close();
 583         let nb_errors =
 584             self.shared.errors.iter().map(|err| self.tcx().sess.struct_err(&err).emit()).count();
 585         if nb_errors > 0 {
 586             Err(Error::new(io::Error::new(io::ErrorKind::Other, "I/O error"), ""))
 587         } else {
 588             Ok(())
 589         }
 590     }
 591
 592     fn mod_item_in(&mut self, item: &clean::Item) -> Result<(), Error> {
 593         // Stripped modules survive the rustdoc passes (i.e., `strip-private`)
 594         // if they contain impls for public types. These modules can also
 595         // contain items such as publicly re-exported structures.
 596         //
 597         // External crates will provide links to these structures, so
 598         // these modules are recursed into, but not rendered normally
 599         // (a flag on the context).
 600         if !self.render_redirect_pages {
 601             self.render_redirect_pages = item.is_stripped();
 602         }
 603         let scx = &self.shared;
 604         let item_name = item.name.as_ref().unwrap().to_string();
 605         self.dst.push(&item_name);
 606         self.current.push(item_name);
 607
 608         info!("Recursing into {}", self.dst.display());
 609
 610         let buf = self.render_item(item, true);
 611         // buf will be empty if the module is stripped and there is no redirect for it
 612         if !buf.is_empty() {
 613             self.shared.ensure_dir(&self.dst)?;
 614             let joint_dst = self.dst.join("index.html");
 615             scx.fs.write(&joint_dst, buf.as_bytes())?;
 616         }
 617
 618         // Render sidebar-items.js used throughout this module.
 619         if !self.render_redirect_pages {
 620             let module = match *item.kind {
 621                 clean::StrippedItem(box clean::ModuleItem(ref m)) | clean::ModuleItem(ref m) => m,
 622                 _ => unreachable!(),
 623             };
 624             let items = self.build_sidebar_items(module);
 625             let js_dst = self.dst.join("sidebar-items.js");
 626             let v = format!("initSidebarItems({});", serde_json::to_string(&items).unwrap());
 627             scx.fs.write(&js_dst, &v)?;
 628         }
 629         Ok(())
 630     }
 631
 632     fn mod_item_out(&mut self) -> Result<(), Error> {
 633         info!("Recursed; leaving {}", self.dst.display());
 634
 635         // Go back to where we were at
 636         self.dst.pop();
 637         self.current.pop();
 638         Ok(())
 639     }
 640
 641     fn item(&mut self, item: clean::Item) -> Result<(), Error> {
 642         // Stripped modules survive the rustdoc passes (i.e., `strip-private`)
 643         // if they contain impls for public types. These modules can also
 644         // contain items such as publicly re-exported structures.
 645         //
 646         // External crates will provide links to these structures, so
 647         // these modules are recursed into, but not rendered normally
 648         // (a flag on the context).
 649         if !self.render_redirect_pages {
 650             self.render_redirect_pages = item.is_stripped();
 651         }
 652
 653         let buf = self.render_item(&item, false);
 654         // buf will be empty if the item is stripped and there is no redirect for it
 655         if !buf.is_empty() {
 656             let name = item.name.as_ref().unwrap();
 657             let item_type = item.type_();
 658             let file_name = &item_path(item_type, &name.as_str());
 659             self.shared.ensure_dir(&self.dst)?;
 660             let joint_dst = self.dst.join(file_name);
 661             self.shared.fs.write(&joint_dst, buf.as_bytes())?;
 662
 663             if !self.render_redirect_pages {
 664                 self.shared.all.borrow_mut().append(full_path(self, &item), &item_type);
 665             }
 666             // If the item is a macro, redirect from the old macro URL (with !)
 667             // to the new one (without).
 668             if item_type == ItemType::Macro {
 669                 let redir_name = format!("{}.{}!.html", item_type, name);
 670                 if let Some(ref redirections) = self.shared.redirections {
 671                     let crate_name = &self.shared.layout.krate;
 672                     redirections.borrow_mut().insert(
 673                         format!("{}/{}", crate_name, redir_name),
 674                         format!("{}/{}", crate_name, file_name),
 675                     );
 676                 } else {
 677                     let v = layout::redirect(file_name);
 678                     let redir_dst = self.dst.join(redir_name);
 679                     self.shared.fs.write(&redir_dst, v.as_bytes())?;
 680                 }
 681             }
 682         }
 683         Ok(())
 684     }
 685
 686     fn cache(&self) -> &Cache {
 687         &self.cache
 688     }
 689 }
 690
 691 fn make_item_keywords(it: &clean::Item) -> String {
 692     format!("{}, {}", BASIC_KEYWORDS, it.name.as_ref().unwrap())
 693 }