1 //! HTML formatting module
3 //! This module contains a large number of `fmt::Display` implementations for
4 //! various types in `rustdoc::clean`. These implementations all currently
5 //! assume that HTML output is desired, although it may be possible to redesign
6 //! them in the future to instead emit any format desired.
11 use std::iter::{self, once};
14 use rustc_attr::{ConstStability, StabilityLevel};
15 use rustc_data_structures::captures::Captures;
16 use rustc_data_structures::fx::FxHashSet;
18 use rustc_hir::def::DefKind;
19 use rustc_hir::def_id::DefId;
20 use rustc_metadata::creader::{CStore, LoadedMacro};
22 use rustc_middle::ty::DefIdTree;
23 use rustc_middle::ty::TyCtxt;
24 use rustc_span::symbol::kw;
25 use rustc_span::{sym, Symbol};
26 use rustc_target::spec::abi::Abi;
28 use itertools::Itertools;
31 self, types::ExternalLocation, utils::find_nearest_parent_module, ExternalCrate, ItemId,
34 use crate::formats::item_type::ItemType;
35 use crate::html::escape::Escape;
36 use crate::html::render::Context;
38 use super::url_parts_builder::estimate_item_path_byte_length;
39 use super::url_parts_builder::UrlPartsBuilder;
41 pub(crate) trait Print {
42 fn print(self, buffer: &mut Buffer);
47 F: FnOnce(&mut Buffer),
49 fn print(self, buffer: &mut Buffer) {
54 impl Print for String {
55 fn print(self, buffer: &mut Buffer) {
56 buffer.write_str(&self);
60 impl Print for &'_ str {
61 fn print(self, buffer: &mut Buffer) {
62 buffer.write_str(self);
66 #[derive(Debug, Clone)]
67 pub(crate) struct Buffer {
72 impl core::fmt::Write for Buffer {
74 fn write_str(&mut self, s: &str) -> fmt::Result {
75 self.buffer.write_str(s)
79 fn write_char(&mut self, c: char) -> fmt::Result {
80 self.buffer.write_char(c)
84 fn write_fmt(&mut self, args: fmt::Arguments<'_>) -> fmt::Result {
85 self.buffer.write_fmt(args)
90 pub(crate) fn empty_from(v: &Buffer) -> Buffer {
91 Buffer { for_html: v.for_html, buffer: String::new() }
94 pub(crate) fn html() -> Buffer {
95 Buffer { for_html: true, buffer: String::new() }
98 pub(crate) fn new() -> Buffer {
99 Buffer { for_html: false, buffer: String::new() }
102 pub(crate) fn is_empty(&self) -> bool {
103 self.buffer.is_empty()
106 pub(crate) fn into_inner(self) -> String {
110 pub(crate) fn insert_str(&mut self, idx: usize, s: &str) {
111 self.buffer.insert_str(idx, s);
114 pub(crate) fn push_str(&mut self, s: &str) {
115 self.buffer.push_str(s);
118 pub(crate) fn push_buffer(&mut self, other: Buffer) {
119 self.buffer.push_str(&other.buffer);
122 // Intended for consumption by write! and writeln! (std::fmt) but without
123 // the fmt::Result return type imposed by fmt::Write (and avoiding the trait
125 pub(crate) fn write_str(&mut self, s: &str) {
126 self.buffer.push_str(s);
129 // Intended for consumption by write! and writeln! (std::fmt) but without
130 // the fmt::Result return type imposed by fmt::Write (and avoiding the trait
132 pub(crate) fn write_fmt(&mut self, v: fmt::Arguments<'_>) {
134 self.buffer.write_fmt(v).unwrap();
137 pub(crate) fn to_display<T: Print>(mut self, t: T) -> String {
142 pub(crate) fn is_for_html(&self) -> bool {
146 pub(crate) fn reserve(&mut self, additional: usize) {
147 self.buffer.reserve(additional)
150 pub(crate) fn len(&self) -> usize {
155 pub(crate) fn comma_sep<T: fmt::Display>(
156 items: impl Iterator<Item = T>,
157 space_after_comma: bool,
158 ) -> impl fmt::Display {
159 display_fn(move |f| {
160 for (i, item) in items.enumerate() {
162 write!(f, ",{}", if space_after_comma { " " } else { "" })?;
164 fmt::Display::fmt(&item, f)?;
170 pub(crate) fn print_generic_bounds<'a, 'tcx: 'a>(
171 bounds: &'a [clean::GenericBound],
172 cx: &'a Context<'tcx>,
173 ) -> impl fmt::Display + 'a + Captures<'tcx> {
174 display_fn(move |f| {
175 let mut bounds_dup = FxHashSet::default();
177 for (i, bound) in bounds.iter().filter(|b| bounds_dup.insert(b.clone())).enumerate() {
181 fmt::Display::fmt(&bound.print(cx), f)?;
187 impl clean::GenericParamDef {
188 pub(crate) fn print<'a, 'tcx: 'a>(
190 cx: &'a Context<'tcx>,
191 ) -> impl fmt::Display + 'a + Captures<'tcx> {
192 display_fn(move |f| match &self.kind {
193 clean::GenericParamDefKind::Lifetime { outlives } => {
194 write!(f, "{}", self.name)?;
196 if !outlives.is_empty() {
198 for (i, lt) in outlives.iter().enumerate() {
202 write!(f, "{}", lt.print())?;
208 clean::GenericParamDefKind::Type { bounds, default, .. } => {
209 f.write_str(self.name.as_str())?;
211 if !bounds.is_empty() {
213 write!(f, ": {:#}", print_generic_bounds(bounds, cx))?;
215 write!(f, ": {}", print_generic_bounds(bounds, cx))?;
219 if let Some(ref ty) = default {
221 write!(f, " = {:#}", ty.print(cx))?;
223 write!(f, " = {}", ty.print(cx))?;
229 clean::GenericParamDefKind::Const { ty, default, .. } => {
231 write!(f, "const {}: {:#}", self.name, ty.print(cx))?;
233 write!(f, "const {}: {}", self.name, ty.print(cx))?;
236 if let Some(default) = default {
238 write!(f, " = {:#}", default)?;
240 write!(f, " = {}", default)?;
250 impl clean::Generics {
251 pub(crate) fn print<'a, 'tcx: 'a>(
253 cx: &'a Context<'tcx>,
254 ) -> impl fmt::Display + 'a + Captures<'tcx> {
255 display_fn(move |f| {
256 let mut real_params =
257 self.params.iter().filter(|p| !p.is_synthetic_type_param()).peekable();
258 if real_params.peek().is_none() {
263 write!(f, "<{:#}>", comma_sep(real_params.map(|g| g.print(cx)), true))
265 write!(f, "<{}>", comma_sep(real_params.map(|g| g.print(cx)), true))
271 #[derive(Clone, Copy, PartialEq, Eq)]
272 pub(crate) enum Ending {
277 /// * The Generics from which to emit a where-clause.
278 /// * The number of spaces to indent each line with.
279 /// * Whether the where-clause needs to add a comma and newline after the last bound.
280 pub(crate) fn print_where_clause<'a, 'tcx: 'a>(
281 gens: &'a clean::Generics,
282 cx: &'a Context<'tcx>,
285 ) -> impl fmt::Display + 'a + Captures<'tcx> {
288 display_fn(move |f| {
289 let mut where_predicates = gens.where_predicates.iter().filter(|pred| {
290 !matches!(pred, clean::WherePredicate::BoundPredicate { bounds, .. } if bounds.is_empty())
292 display_fn(move |f| {
296 f.write_str("<br>")?;
300 clean::WherePredicate::BoundPredicate { ty, bounds, bound_params } => {
301 let ty_cx = ty.print(cx);
302 let generic_bounds = print_generic_bounds(bounds, cx);
304 if bound_params.is_empty() {
306 write!(f, "{ty_cx:#}: {generic_bounds:#}")
308 write!(f, "{ty_cx}: {generic_bounds}")
314 "for<{:#}> {ty_cx:#}: {generic_bounds:#}",
315 comma_sep(bound_params.iter().map(|lt| lt.print()), true)
320 "for<{}> {ty_cx}: {generic_bounds}",
321 comma_sep(bound_params.iter().map(|lt| lt.print()), true)
326 clean::WherePredicate::RegionPredicate { lifetime, bounds } => {
327 let mut bounds_display = String::new();
328 for bound in bounds.iter().map(|b| b.print(cx)) {
329 write!(bounds_display, "{bound} + ")?;
331 bounds_display.truncate(bounds_display.len() - " + ".len());
332 write!(f, "{}: {bounds_display}", lifetime.print())
334 clean::WherePredicate::EqPredicate { lhs, rhs } => {
336 write!(f, "{:#} == {:#}", lhs.print(cx), rhs.print(cx))
338 write!(f, "{} == {}", lhs.print(cx), rhs.print(cx))
345 if where_predicates.peek().is_none() {
349 let where_preds = comma_sep(where_predicates, false);
350 let clause = if f.alternate() {
351 if ending == Ending::Newline {
352 // add a space so stripping <br> tags and breaking spaces still renders properly
353 format!(" where{where_preds}, ")
355 format!(" where{where_preds}")
358 let mut br_with_padding = String::with_capacity(6 * indent + 28);
359 br_with_padding.push_str("<br>");
360 for _ in 0..indent + 4 {
361 br_with_padding.push_str(" ");
363 let where_preds = where_preds.to_string().replace("<br>", &br_with_padding);
365 if ending == Ending::Newline {
366 let mut clause = " ".repeat(indent.saturating_sub(1));
367 // add a space so stripping <br> tags and breaking spaces still renders properly
370 " <span class=\"where fmt-newline\">where{where_preds}, </span>"
374 // insert a <br> tag after a single space but before multiple spaces at the start
376 format!(" <br><span class=\"where\">where{where_preds}</span>")
378 let mut clause = br_with_padding;
379 clause.truncate(clause.len() - 5 * " ".len());
380 write!(clause, " <span class=\"where\">where{where_preds}</span>")?;
385 write!(f, "{clause}")
389 impl clean::Lifetime {
390 pub(crate) fn print(&self) -> impl fmt::Display + '_ {
395 impl clean::Constant {
396 pub(crate) fn print(&self, tcx: TyCtxt<'_>) -> impl fmt::Display + '_ {
397 let expr = self.expr(tcx);
400 if f.alternate() { f.write_str(&expr) } else { write!(f, "{}", Escape(&expr)) }
406 impl clean::PolyTrait {
407 fn print<'a, 'tcx: 'a>(
409 cx: &'a Context<'tcx>,
410 ) -> impl fmt::Display + 'a + Captures<'tcx> {
411 display_fn(move |f| {
412 if !self.generic_params.is_empty() {
417 comma_sep(self.generic_params.iter().map(|g| g.print(cx)), true)
423 comma_sep(self.generic_params.iter().map(|g| g.print(cx)), true)
428 write!(f, "{:#}", self.trait_.print(cx))
430 write!(f, "{}", self.trait_.print(cx))
436 impl clean::GenericBound {
437 pub(crate) fn print<'a, 'tcx: 'a>(
439 cx: &'a Context<'tcx>,
440 ) -> impl fmt::Display + 'a + Captures<'tcx> {
441 display_fn(move |f| match self {
442 clean::GenericBound::Outlives(lt) => write!(f, "{}", lt.print()),
443 clean::GenericBound::TraitBound(ty, modifier) => {
444 let modifier_str = match modifier {
445 hir::TraitBoundModifier::None => "",
446 hir::TraitBoundModifier::Maybe => "?",
447 // ~const is experimental; do not display those bounds in rustdoc
448 hir::TraitBoundModifier::MaybeConst => "",
451 write!(f, "{}{:#}", modifier_str, ty.print(cx))
453 write!(f, "{}{}", modifier_str, ty.print(cx))
460 impl clean::GenericArgs {
461 fn print<'a, 'tcx: 'a>(
463 cx: &'a Context<'tcx>,
464 ) -> impl fmt::Display + 'a + Captures<'tcx> {
465 display_fn(move |f| {
467 clean::GenericArgs::AngleBracketed { args, bindings } => {
468 if !args.is_empty() || !bindings.is_empty() {
472 f.write_str("<")?;
474 let mut comma = false;
475 for arg in args.iter() {
481 write!(f, "{:#}", arg.print(cx))?;
483 write!(f, "{}", arg.print(cx))?;
486 for binding in bindings.iter() {
492 write!(f, "{:#}", binding.print(cx))?;
494 write!(f, "{}", binding.print(cx))?;
500 f.write_str(">")?;
504 clean::GenericArgs::Parenthesized { inputs, output } => {
506 let mut comma = false;
507 for ty in inputs.iter() {
513 write!(f, "{:#}", ty.print(cx))?;
515 write!(f, "{}", ty.print(cx))?;
519 if let Some(ref ty) = *output {
521 write!(f, " -> {:#}", ty.print(cx))?;
523 write!(f, " -> {}", ty.print(cx))?;
533 // Possible errors when computing href link source for a `DefId`
534 #[derive(PartialEq, Eq)]
535 pub(crate) enum HrefError {
536 /// This item is known to rustdoc, but from a crate that does not have documentation generated.
538 /// This can only happen for non-local items.
542 /// Crate `a` defines a public trait and crate `b` – the target crate that depends on `a` –
543 /// implements it for a local type.
544 /// We document `b` but **not** `a` (we only _build_ the latter – with `rustc`):
547 /// rustc a.rs --crate-type=lib
548 /// rustdoc b.rs --crate-type=lib --extern=a=liba.rlib
551 /// Now, the associated items in the trait impl want to link to the corresponding item in the
552 /// trait declaration (see `html::render::assoc_href_attr`) but it's not available since their
553 /// *documentation (was) not built*.
554 DocumentationNotBuilt,
555 /// This can only happen for non-local items when `--document-private-items` is not passed.
557 // Not in external cache, href link should be in same page
561 // Panics if `syms` is empty.
562 pub(crate) fn join_with_double_colon(syms: &[Symbol]) -> String {
563 let mut s = String::with_capacity(estimate_item_path_byte_length(syms.len()));
564 s.push_str(syms[0].as_str());
565 for sym in &syms[1..] {
567 s.push_str(sym.as_str());
572 /// This function is to get the external macro path because they are not in the cache used in
573 /// `href_with_root_path`.
574 fn generate_macro_def_id_path(
577 root_path: Option<&str>,
578 ) -> Result<(String, ItemType, Vec<Symbol>), HrefError> {
579 let tcx = cx.shared.tcx;
580 let crate_name = tcx.crate_name(def_id.krate).to_string();
581 let cache = cx.cache();
583 let fqp: Vec<Symbol> = tcx
588 // extern blocks (and a few others things) have an empty name.
589 match elem.data.get_opt_name() {
590 Some(s) if !s.is_empty() => Some(s),
595 let relative = fqp.iter().map(|elem| elem.to_string());
596 let cstore = CStore::from_tcx(tcx);
597 // We need this to prevent a `panic` when this function is used from intra doc links...
598 if !cstore.has_crate_data(def_id.krate) {
599 debug!("No data for crate {}", crate_name);
600 return Err(HrefError::NotInExternalCache);
602 // Check to see if it is a macro 2.0 or built-in macro.
603 // More information in <https://rust-lang.github.io/rfcs/1584-macros.html>.
604 let is_macro_2 = match cstore.load_macro_untracked(def_id, tcx.sess) {
605 LoadedMacro::MacroDef(def, _) => {
606 // If `ast_def.macro_rules` is `true`, then it's not a macro 2.0.
607 matches!(&def.kind, ast::ItemKind::MacroDef(ast_def) if !ast_def.macro_rules)
612 let mut path = if is_macro_2 {
613 once(crate_name.clone()).chain(relative).collect()
615 vec![crate_name.clone(), relative.last().unwrap()]
618 // The minimum we can have is the crate name followed by the macro name. If shorter, then
619 // it means that that `relative` was empty, which is an error.
620 debug!("macro path cannot be empty!");
621 return Err(HrefError::NotInExternalCache);
624 if let Some(last) = path.last_mut() {
625 *last = format!("macro.{}.html", last);
628 let url = match cache.extern_locations[&def_id.krate] {
629 ExternalLocation::Remote(ref s) => {
630 // `ExternalLocation::Remote` always end with a `/`.
631 format!("{}{}", s, path.join("/"))
633 ExternalLocation::Local => {
634 // `root_path` always end with a `/`.
635 format!("{}{}/{}", root_path.unwrap_or(""), crate_name, path.join("/"))
637 ExternalLocation::Unknown => {
638 debug!("crate {} not in cache when linkifying macros", crate_name);
639 return Err(HrefError::NotInExternalCache);
642 Ok((url, ItemType::Macro, fqp))
645 pub(crate) fn href_with_root_path(
648 root_path: Option<&str>,
649 ) -> Result<(String, ItemType, Vec<Symbol>), HrefError> {
651 let def_kind = tcx.def_kind(did);
652 let did = match def_kind {
653 DefKind::AssocTy | DefKind::AssocFn | DefKind::AssocConst | DefKind::Variant => {
654 // documented on their parent's page
659 let cache = cx.cache();
660 let relative_to = &cx.current;
661 fn to_module_fqp(shortty: ItemType, fqp: &[Symbol]) -> &[Symbol] {
662 if shortty == ItemType::Module { fqp } else { &fqp[..fqp.len() - 1] }
666 && !cache.access_levels.is_public(did)
667 && !cache.document_private
668 && !cache.primitive_locations.values().any(|&id| id == did)
670 return Err(HrefError::Private);
673 let mut is_remote = false;
674 let (fqp, shortty, mut url_parts) = match cache.paths.get(&did) {
675 Some(&(ref fqp, shortty)) => (fqp, shortty, {
676 let module_fqp = to_module_fqp(shortty, fqp.as_slice());
677 debug!(?fqp, ?shortty, ?module_fqp);
678 href_relative_parts(module_fqp, relative_to).collect()
681 if let Some(&(ref fqp, shortty)) = cache.external_paths.get(&did) {
682 let module_fqp = to_module_fqp(shortty, fqp);
686 match cache.extern_locations[&did.krate] {
687 ExternalLocation::Remote(ref s) => {
689 let s = s.trim_end_matches('/');
690 let mut builder = UrlPartsBuilder::singleton(s);
691 builder.extend(module_fqp.iter().copied());
694 ExternalLocation::Local => {
695 href_relative_parts(module_fqp, relative_to).collect()
697 ExternalLocation::Unknown => return Err(HrefError::DocumentationNotBuilt),
700 } else if matches!(def_kind, DefKind::Macro(_)) {
701 return generate_macro_def_id_path(did, cx, root_path);
703 return Err(HrefError::NotInExternalCache);
708 if let Some(root_path) = root_path {
709 let root = root_path.trim_end_matches('/');
710 url_parts.push_front(root);
715 ItemType::Module => {
716 url_parts.push("index.html");
719 let prefix = shortty.as_str();
720 let last = fqp.last().unwrap();
721 url_parts.push_fmt(format_args!("{}.{}.html", prefix, last));
724 Ok((url_parts.finish(), shortty, fqp.to_vec()))
730 ) -> Result<(String, ItemType, Vec<Symbol>), HrefError> {
731 href_with_root_path(did, cx, None)
734 /// Both paths should only be modules.
735 /// This is because modules get their own directories; that is, `std::vec` and `std::vec::Vec` will
736 /// both need `../iter/trait.Iterator.html` to get at the iterator trait.
737 pub(crate) fn href_relative_parts<'fqp>(
739 relative_to_fqp: &[Symbol],
740 ) -> Box<dyn Iterator<Item = Symbol> + 'fqp> {
741 for (i, (f, r)) in fqp.iter().zip(relative_to_fqp.iter()).enumerate() {
742 // e.g. linking to std::iter from std::vec (`dissimilar_part_count` will be 1)
744 let dissimilar_part_count = relative_to_fqp.len() - i;
745 let fqp_module = &fqp[i..fqp.len()];
747 iter::repeat(sym::dotdot)
748 .take(dissimilar_part_count)
749 .chain(fqp_module.iter().copied()),
753 // e.g. linking to std::sync::atomic from std::sync
754 if relative_to_fqp.len() < fqp.len() {
755 Box::new(fqp[relative_to_fqp.len()..fqp.len()].iter().copied())
756 // e.g. linking to std::sync from std::sync::atomic
757 } else if fqp.len() < relative_to_fqp.len() {
758 let dissimilar_part_count = relative_to_fqp.len() - fqp.len();
759 Box::new(iter::repeat(sym::dotdot).take(dissimilar_part_count))
760 // linking to the same module
762 Box::new(iter::empty())
766 /// Used to render a [`clean::Path`].
767 fn resolved_path<'cx>(
768 w: &mut fmt::Formatter<'_>,
773 cx: &'cx Context<'_>,
775 let last = path.segments.last().unwrap();
778 for seg in &path.segments[..path.segments.len() - 1] {
779 write!(w, "{}::", if seg.name == kw::PathRoot { "" } else { seg.name.as_str() })?;
783 write!(w, "{}{:#}", &last.name, last.args.print(cx))?;
785 let path = if use_absolute {
786 if let Ok((_, _, fqp)) = href(did, cx) {
789 join_with_double_colon(&fqp[..fqp.len() - 1]),
790 anchor(did, *fqp.last().unwrap(), cx)
793 last.name.to_string()
796 anchor(did, last.name, cx).to_string()
798 write!(w, "{}{}", path, last.args.print(cx))?;
804 f: &mut fmt::Formatter<'_>,
805 prim: clean::PrimitiveType,
809 primitive_link_fragment(f, prim, name, "", cx)
812 fn primitive_link_fragment(
813 f: &mut fmt::Formatter<'_>,
814 prim: clean::PrimitiveType,
820 let mut needs_termination = false;
822 match m.primitive_locations.get(&prim) {
823 Some(&def_id) if def_id.is_local() => {
824 let len = cx.current.len();
825 let len = if len == 0 { 0 } else { len - 1 };
828 "<a class=\"primitive\" href=\"{}primitive.{}.html{fragment}\">",
832 needs_termination = true;
835 let loc = match m.extern_locations[&def_id.krate] {
836 ExternalLocation::Remote(ref s) => {
837 let cname_sym = ExternalCrate { crate_num: def_id.krate }.name(cx.tcx());
838 let builder: UrlPartsBuilder =
839 [s.as_str().trim_end_matches('/'), cname_sym.as_str()]
844 ExternalLocation::Local => {
845 let cname_sym = ExternalCrate { crate_num: def_id.krate }.name(cx.tcx());
846 Some(if cx.current.first() == Some(&cname_sym) {
847 iter::repeat(sym::dotdot).take(cx.current.len() - 1).collect()
849 iter::repeat(sym::dotdot)
850 .take(cx.current.len())
851 .chain(iter::once(cname_sym))
855 ExternalLocation::Unknown => None,
857 if let Some(mut loc) = loc {
858 loc.push_fmt(format_args!("primitive.{}.html", prim.as_sym()));
859 write!(f, "<a class=\"primitive\" href=\"{}{fragment}\">", loc.finish())?;
860 needs_termination = true;
866 write!(f, "{}", name)?;
867 if needs_termination {
873 /// Helper to render type parameters
874 fn tybounds<'a, 'tcx: 'a>(
875 bounds: &'a [clean::PolyTrait],
876 lt: &'a Option<clean::Lifetime>,
877 cx: &'a Context<'tcx>,
878 ) -> impl fmt::Display + 'a + Captures<'tcx> {
879 display_fn(move |f| {
880 for (i, bound) in bounds.iter().enumerate() {
885 fmt::Display::fmt(&bound.print(cx), f)?;
888 if let Some(lt) = lt {
890 fmt::Display::fmt(<.print(), f)?;
896 pub(crate) fn anchor<'a, 'cx: 'a>(
899 cx: &'cx Context<'_>,
900 ) -> impl fmt::Display + 'a {
901 let parts = href(did, cx);
902 display_fn(move |f| {
903 if let Ok((url, short_ty, fqp)) = parts {
906 r#"<a class="{}" href="{}" title="{} {}">{}</a>"#,
910 join_with_double_colon(&fqp),
914 write!(f, "{}", text)
921 f: &mut fmt::Formatter<'_>,
923 cx: &'cx Context<'_>,
925 trace!("fmt_type(t = {:?})", t);
928 clean::Generic(name) => write!(f, "{}", name),
929 clean::Type::Path { ref path } => {
930 // Paths like `T::Output` and `Self::Output` should be rendered with all segments.
931 let did = path.def_id();
932 resolved_path(f, did, path, path.is_assoc_ty(), use_absolute, cx)
934 clean::DynTrait(ref bounds, ref lt) => {
935 f.write_str("dyn ")?;
936 fmt::Display::fmt(&tybounds(bounds, lt, cx), f)
938 clean::Infer => write!(f, "_"),
939 clean::Primitive(clean::PrimitiveType::Never) => {
940 primitive_link(f, PrimitiveType::Never, "!", cx)
942 clean::Primitive(prim) => primitive_link(f, prim, prim.as_sym().as_str(), cx),
943 clean::BareFunction(ref decl) => {
948 decl.print_hrtb_with_space(cx),
949 decl.unsafety.print_with_space(),
950 print_abi_with_space(decl.abi),
957 decl.print_hrtb_with_space(cx),
958 decl.unsafety.print_with_space(),
959 print_abi_with_space(decl.abi)
961 primitive_link(f, PrimitiveType::Fn, "fn", cx)?;
962 write!(f, "{}", decl.decl.print(cx))
965 clean::Tuple(ref typs) => {
967 &[] => primitive_link(f, PrimitiveType::Unit, "()", cx),
969 if let clean::Generic(name) = one {
970 primitive_link(f, PrimitiveType::Tuple, &format!("({name},)"), cx)
973 // Carry `f.alternate()` into this display w/o branching manually.
974 fmt::Display::fmt(&one.print(cx), f)?;
979 let generic_names: Vec<Symbol> = many
981 .filter_map(|t| match t {
982 clean::Generic(name) => Some(*name),
986 let is_generic = generic_names.len() == many.len();
990 PrimitiveType::Tuple,
991 &format!("({})", generic_names.iter().map(|s| s.as_str()).join(", ")),
996 for (i, item) in many.iter().enumerate() {
1000 // Carry `f.alternate()` into this display w/o branching manually.
1001 fmt::Display::fmt(&item.print(cx), f)?;
1008 clean::Slice(ref t) => match **t {
1009 clean::Generic(name) => {
1010 primitive_link(f, PrimitiveType::Slice, &format!("[{name}]"), cx)
1014 fmt::Display::fmt(&t.print(cx), f)?;
1018 clean::Array(ref t, ref n) => {
1019 primitive_link(f, PrimitiveType::Array, "[", cx)?;
1020 fmt::Display::fmt(&t.print(cx), f)?;
1022 primitive_link(f, PrimitiveType::Array, &format!("; {}]", n), cx)
1024 primitive_link(f, PrimitiveType::Array, &format!("; {}]", Escape(n)), cx)
1027 clean::RawPointer(m, ref t) => {
1029 hir::Mutability::Mut => "mut",
1030 hir::Mutability::Not => "const",
1033 if matches!(**t, clean::Generic(_)) || t.is_assoc_ty() {
1034 let text = if f.alternate() {
1035 format!("*{} {:#}", m, t.print(cx))
1037 format!("*{} {}", m, t.print(cx))
1039 primitive_link(f, clean::PrimitiveType::RawPointer, &text, cx)
1041 primitive_link(f, clean::PrimitiveType::RawPointer, &format!("*{} ", m), cx)?;
1042 fmt::Display::fmt(&t.print(cx), f)
1045 clean::BorrowedRef { lifetime: ref l, mutability, type_: ref ty } => {
1047 Some(l) => format!("{} ", l.print()),
1050 let m = mutability.print_with_space();
1051 let amp = if f.alternate() { "&".to_string() } else { "&".to_string() };
1053 clean::DynTrait(ref bounds, ref trait_lt)
1054 if bounds.len() > 1 || trait_lt.is_some() =>
1056 write!(f, "{}{}{}(", amp, lt, m)?;
1057 fmt_type(ty, f, use_absolute, cx)?;
1060 clean::Generic(..) => {
1063 PrimitiveType::Reference,
1064 &format!("{}{}{}", amp, lt, m),
1067 fmt_type(ty, f, use_absolute, cx)
1070 write!(f, "{}{}{}", amp, lt, m)?;
1071 fmt_type(ty, f, use_absolute, cx)
1075 clean::ImplTrait(ref bounds) => {
1077 write!(f, "impl {:#}", print_generic_bounds(bounds, cx))
1079 write!(f, "impl {}", print_generic_bounds(bounds, cx))
1082 clean::QPath { ref assoc, ref self_type, ref trait_, should_show_cast } => {
1084 if should_show_cast {
1085 write!(f, "<{:#} as {:#}>::", self_type.print(cx), trait_.print(cx))?
1087 write!(f, "{:#}::", self_type.print(cx))?
1090 if should_show_cast {
1091 write!(f, "<{} as {}>::", self_type.print(cx), trait_.print(cx))?
1093 write!(f, "{}::", self_type.print(cx))?
1096 // It's pretty unsightly to look at `<A as B>::C` in output, and
1097 // we've got hyperlinking on our side, so try to avoid longer
1098 // notation as much as possible by making `C` a hyperlink to trait
1099 // `B` to disambiguate.
1101 // FIXME: this is still a lossy conversion and there should probably
1102 // be a better way of representing this in general? Most of
1103 // the ugliness comes from inlining across crates where
1104 // everything comes in as a fully resolved QPath (hard to
1106 match href(trait_.def_id(), cx) {
1107 Ok((ref url, _, ref path)) if !f.alternate() => {
1110 "<a class=\"associatedtype\" href=\"{url}#{shortty}.{name}\" \
1111 title=\"type {path}::{name}\">{name}</a>{args}",
1113 shortty = ItemType::AssocType,
1115 path = join_with_double_colon(path),
1116 args = assoc.args.print(cx),
1119 _ => write!(f, "{}{:#}", assoc.name, assoc.args.print(cx))?,
1127 pub(crate) fn print<'b, 'a: 'b, 'tcx: 'a>(
1129 cx: &'a Context<'tcx>,
1130 ) -> impl fmt::Display + 'b + Captures<'tcx> {
1131 display_fn(move |f| fmt_type(self, f, false, cx))
1136 pub(crate) fn print<'b, 'a: 'b, 'tcx: 'a>(
1138 cx: &'a Context<'tcx>,
1139 ) -> impl fmt::Display + 'b + Captures<'tcx> {
1140 display_fn(move |f| resolved_path(f, self.def_id(), self, false, false, cx))
1145 pub(crate) fn print<'a, 'tcx: 'a>(
1148 cx: &'a Context<'tcx>,
1149 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1150 display_fn(move |f| {
1152 write!(f, "impl{:#} ", self.generics.print(cx))?;
1154 write!(f, "impl{} ", self.generics.print(cx))?;
1157 if let Some(ref ty) = self.trait_ {
1158 match self.polarity {
1159 ty::ImplPolarity::Positive | ty::ImplPolarity::Reservation => {}
1160 ty::ImplPolarity::Negative => write!(f, "!")?,
1162 fmt::Display::fmt(&ty.print(cx), f)?;
1163 write!(f, " for ")?;
1166 if let clean::Type::Tuple(types) = &self.for_ &&
1167 let [clean::Type::Generic(name)] = &types[..] &&
1168 (self.kind.is_fake_variadic() || self.kind.is_auto())
1170 // Hardcoded anchor library/core/src/primitive_docs.rs
1171 // Link should match `# Trait implementations`
1172 primitive_link_fragment(f, PrimitiveType::Tuple, &format!("({name}₁, {name}₂, …, {name}ₙ)"), "#trait-implementations-1", cx)?;
1173 } else if let clean::BareFunction(bare_fn) = &self.for_ &&
1174 let [clean::Argument { type_: clean::Type::Generic(name), .. }] = &bare_fn.decl.inputs.values[..] &&
1175 (self.kind.is_fake_variadic() || self.kind.is_auto())
1177 // Hardcoded anchor library/core/src/primitive_docs.rs
1178 // Link should match `# Trait implementations`
1180 let hrtb = bare_fn.print_hrtb_with_space(cx);
1181 let unsafety = bare_fn.unsafety.print_with_space();
1182 let abi = print_abi_with_space(bare_fn.abi);
1186 "{hrtb:#}{unsafety}{abi:#}",
1191 "{hrtb}{unsafety}{abi}",
1194 let ellipsis = if bare_fn.decl.c_variadic {
1199 primitive_link_fragment(f, PrimitiveType::Tuple, &format!("fn ({name}₁, {name}₂, …, {name}ₙ{ellipsis})"), "#trait-implementations-1", cx)?;
1201 if let clean::FnRetTy::Return(ty) = &bare_fn.decl.output {
1203 fmt_type(ty, f, use_absolute, cx)?;
1205 } else if let Some(ty) = self.kind.as_blanket_ty() {
1206 fmt_type(ty, f, use_absolute, cx)?;
1208 fmt_type(&self.for_, f, use_absolute, cx)?;
1211 fmt::Display::fmt(&print_where_clause(&self.generics, cx, 0, Ending::Newline), f)?;
1217 impl clean::Arguments {
1218 pub(crate) fn print<'a, 'tcx: 'a>(
1220 cx: &'a Context<'tcx>,
1221 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1222 display_fn(move |f| {
1223 for (i, input) in self.values.iter().enumerate() {
1224 if !input.name.is_empty() {
1225 write!(f, "{}: ", input.name)?;
1228 write!(f, "{:#}", input.type_.print(cx))?;
1230 write!(f, "{}", input.type_.print(cx))?;
1232 if i + 1 < self.values.len() {
1241 impl clean::FnRetTy {
1242 pub(crate) fn print<'a, 'tcx: 'a>(
1244 cx: &'a Context<'tcx>,
1245 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1246 display_fn(move |f| match self {
1247 clean::Return(clean::Tuple(tys)) if tys.is_empty() => Ok(()),
1248 clean::Return(ty) if f.alternate() => {
1249 write!(f, " -> {:#}", ty.print(cx))
1251 clean::Return(ty) => write!(f, " -> {}", ty.print(cx)),
1252 clean::DefaultReturn => Ok(()),
1257 impl clean::BareFunctionDecl {
1258 fn print_hrtb_with_space<'a, 'tcx: 'a>(
1260 cx: &'a Context<'tcx>,
1261 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1262 display_fn(move |f| {
1263 if !self.generic_params.is_empty() {
1267 comma_sep(self.generic_params.iter().map(|g| g.print(cx)), true)
1276 impl clean::FnDecl {
1277 pub(crate) fn print<'b, 'a: 'b, 'tcx: 'a>(
1279 cx: &'a Context<'tcx>,
1280 ) -> impl fmt::Display + 'b + Captures<'tcx> {
1281 display_fn(move |f| {
1282 let ellipsis = if self.c_variadic { ", ..." } else { "" };
1286 "({args:#}{ellipsis}){arrow:#}",
1287 args = self.inputs.print(cx),
1288 ellipsis = ellipsis,
1289 arrow = self.output.print(cx)
1294 "({args}{ellipsis}){arrow}",
1295 args = self.inputs.print(cx),
1296 ellipsis = ellipsis,
1297 arrow = self.output.print(cx)
1303 /// * `header_len`: The length of the function header and name. In other words, the number of
1304 /// characters in the function declaration up to but not including the parentheses.
1305 /// <br>Used to determine line-wrapping.
1306 /// * `indent`: The number of spaces to indent each successive line with, if line-wrapping is
1308 /// * `asyncness`: Whether the function is async or not.
1309 pub(crate) fn full_print<'a, 'tcx: 'a>(
1313 asyncness: hir::IsAsync,
1314 cx: &'a Context<'tcx>,
1315 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1316 display_fn(move |f| self.inner_full_print(header_len, indent, asyncness, f, cx))
1319 fn inner_full_print(
1323 asyncness: hir::IsAsync,
1324 f: &mut fmt::Formatter<'_>,
1327 let amp = if f.alternate() { "&" } else { "&" };
1328 let mut args = Buffer::html();
1329 let mut args_plain = Buffer::new();
1330 for (i, input) in self.inputs.values.iter().enumerate() {
1331 if let Some(selfty) = input.to_self() {
1333 clean::SelfValue => {
1334 args.push_str("self");
1335 args_plain.push_str("self");
1337 clean::SelfBorrowed(Some(ref lt), mtbl) => {
1338 write!(args, "{}{} {}self", amp, lt.print(), mtbl.print_with_space());
1339 write!(args_plain, "&{} {}self", lt.print(), mtbl.print_with_space());
1341 clean::SelfBorrowed(None, mtbl) => {
1342 write!(args, "{}{}self", amp, mtbl.print_with_space());
1343 write!(args_plain, "&{}self", mtbl.print_with_space());
1345 clean::SelfExplicit(ref typ) => {
1347 write!(args, "self: {:#}", typ.print(cx));
1349 write!(args, "self: {}", typ.print(cx));
1351 write!(args_plain, "self: {:#}", typ.print(cx));
1356 args.push_str("<br>");
1359 args.push_str("const ");
1360 args_plain.push_str("const ");
1362 if !input.name.is_empty() {
1363 write!(args, "{}: ", input.name);
1364 write!(args_plain, "{}: ", input.name);
1368 write!(args, "{:#}", input.type_.print(cx));
1370 write!(args, "{}", input.type_.print(cx));
1372 write!(args_plain, "{:#}", input.type_.print(cx));
1374 if i + 1 < self.inputs.values.len() {
1376 args_plain.push_str(",");
1380 let mut args_plain = format!("({})", args_plain.into_inner());
1381 let mut args = args.into_inner();
1383 if self.c_variadic {
1384 args.push_str(",<br> ...");
1385 args_plain.push_str(", ...");
1389 let arrow = if let hir::IsAsync::Async = asyncness {
1390 let output = self.sugared_async_return_type();
1391 arrow_plain = format!("{:#}", output.print(cx));
1392 if f.alternate() { arrow_plain.clone() } else { format!("{}", output.print(cx)) }
1394 arrow_plain = format!("{:#}", self.output.print(cx));
1395 if f.alternate() { arrow_plain.clone() } else { format!("{}", self.output.print(cx)) }
1398 let declaration_len = header_len + args_plain.len() + arrow_plain.len();
1399 let output = if declaration_len > 80 {
1400 let full_pad = format!("<br>{}", " ".repeat(indent + 4));
1401 let close_pad = format!("<br>{}", " ".repeat(indent));
1403 "({pad}{args}{close}){arrow}",
1404 pad = if self.inputs.values.is_empty() { "" } else { &full_pad },
1405 args = args.replace("<br>", &full_pad),
1410 format!("({args}){arrow}", args = args.replace("<br>", " "), arrow = arrow)
1414 write!(f, "{}", output.replace("<br>", "\n"))
1416 write!(f, "{}", output)
1421 impl clean::Visibility {
1422 pub(crate) fn print_with_space<'a, 'tcx: 'a>(
1425 cx: &'a Context<'tcx>,
1426 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1427 use std::fmt::Write as _;
1429 let to_print: Cow<'static, str> = match self {
1430 clean::Public => "pub ".into(),
1431 clean::Inherited => "".into(),
1432 clean::Visibility::Restricted(vis_did) => {
1433 // FIXME(camelid): This may not work correctly if `item_did` is a module.
1434 // However, rustdoc currently never displays a module's
1435 // visibility, so it shouldn't matter.
1436 let parent_module = find_nearest_parent_module(cx.tcx(), item_did.expect_def_id());
1438 if vis_did.is_crate_root() {
1439 "pub(crate) ".into()
1440 } else if parent_module == Some(vis_did) {
1441 // `pub(in foo)` where `foo` is the parent module
1442 // is the same as no visibility modifier
1444 } else if parent_module
1445 .and_then(|parent| find_nearest_parent_module(cx.tcx(), parent))
1448 "pub(super) ".into()
1450 let path = cx.tcx().def_path(vis_did);
1451 debug!("path={:?}", path);
1452 // modified from `resolved_path()` to work with `DefPathData`
1453 let last_name = path.data.last().unwrap().data.get_opt_name().unwrap();
1454 let anchor = anchor(vis_did, last_name, cx).to_string();
1456 let mut s = "pub(in ".to_owned();
1457 for seg in &path.data[..path.data.len() - 1] {
1458 let _ = write!(s, "{}::", seg.data.get_opt_name().unwrap());
1460 let _ = write!(s, "{}) ", anchor);
1465 display_fn(move |f| write!(f, "{}", to_print))
1468 /// This function is the same as print_with_space, except that it renders no links.
1469 /// It's used for macros' rendered source view, which is syntax highlighted and cannot have
1471 pub(crate) fn to_src_with_space<'a, 'tcx: 'a>(
1475 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1476 let to_print = match self {
1477 clean::Public => "pub ".to_owned(),
1478 clean::Inherited => String::new(),
1479 clean::Visibility::Restricted(vis_did) => {
1480 // FIXME(camelid): This may not work correctly if `item_did` is a module.
1481 // However, rustdoc currently never displays a module's
1482 // visibility, so it shouldn't matter.
1483 let parent_module = find_nearest_parent_module(tcx, item_did);
1485 if vis_did.is_crate_root() {
1486 "pub(crate) ".to_owned()
1487 } else if parent_module == Some(vis_did) {
1488 // `pub(in foo)` where `foo` is the parent module
1489 // is the same as no visibility modifier
1491 } else if parent_module.and_then(|parent| find_nearest_parent_module(tcx, parent))
1494 "pub(super) ".to_owned()
1496 format!("pub(in {}) ", tcx.def_path_str(vis_did))
1500 display_fn(move |f| f.write_str(&to_print))
1504 pub(crate) trait PrintWithSpace {
1505 fn print_with_space(&self) -> &str;
1508 impl PrintWithSpace for hir::Unsafety {
1509 fn print_with_space(&self) -> &str {
1511 hir::Unsafety::Unsafe => "unsafe ",
1512 hir::Unsafety::Normal => "",
1517 impl PrintWithSpace for hir::IsAsync {
1518 fn print_with_space(&self) -> &str {
1520 hir::IsAsync::Async => "async ",
1521 hir::IsAsync::NotAsync => "",
1526 impl PrintWithSpace for hir::Mutability {
1527 fn print_with_space(&self) -> &str {
1529 hir::Mutability::Not => "",
1530 hir::Mutability::Mut => "mut ",
1535 pub(crate) fn print_constness_with_space(
1537 s: Option<ConstStability>,
1540 // const stable or when feature(staged_api) is not set
1542 hir::Constness::Const,
1543 Some(ConstStability { level: StabilityLevel::Stable { .. }, .. }),
1545 | (hir::Constness::Const, None) => "const ",
1546 // const unstable or not const
1551 impl clean::Import {
1552 pub(crate) fn print<'a, 'tcx: 'a>(
1554 cx: &'a Context<'tcx>,
1555 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1556 display_fn(move |f| match self.kind {
1557 clean::ImportKind::Simple(name) => {
1558 if name == self.source.path.last() {
1559 write!(f, "use {};", self.source.print(cx))
1561 write!(f, "use {} as {};", self.source.print(cx), name)
1564 clean::ImportKind::Glob => {
1565 if self.source.path.segments.is_empty() {
1568 write!(f, "use {}::*;", self.source.print(cx))
1575 impl clean::ImportSource {
1576 pub(crate) fn print<'a, 'tcx: 'a>(
1578 cx: &'a Context<'tcx>,
1579 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1580 display_fn(move |f| match self.did {
1581 Some(did) => resolved_path(f, did, &self.path, true, false, cx),
1583 for seg in &self.path.segments[..self.path.segments.len() - 1] {
1584 write!(f, "{}::", seg.name)?;
1586 let name = self.path.last();
1587 if let hir::def::Res::PrimTy(p) = self.path.res {
1588 primitive_link(f, PrimitiveType::from(p), name.as_str(), cx)?;
1590 write!(f, "{}", name)?;
1598 impl clean::TypeBinding {
1599 pub(crate) fn print<'a, 'tcx: 'a>(
1601 cx: &'a Context<'tcx>,
1602 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1603 display_fn(move |f| {
1604 f.write_str(self.assoc.name.as_str())?;
1606 write!(f, "{:#}", self.assoc.args.print(cx))?;
1608 write!(f, "{}", self.assoc.args.print(cx))?;
1611 clean::TypeBindingKind::Equality { ref term } => {
1613 write!(f, " = {:#}", term.print(cx))?;
1615 write!(f, " = {}", term.print(cx))?;
1618 clean::TypeBindingKind::Constraint { ref bounds } => {
1619 if !bounds.is_empty() {
1621 write!(f, ": {:#}", print_generic_bounds(bounds, cx))?;
1623 write!(f, ": {}", print_generic_bounds(bounds, cx))?;
1633 pub(crate) fn print_abi_with_space(abi: Abi) -> impl fmt::Display {
1634 display_fn(move |f| {
1635 let quot = if f.alternate() { "\"" } else { """ };
1637 Abi::Rust => Ok(()),
1638 abi => write!(f, "extern {0}{1}{0} ", quot, abi.name()),
1643 pub(crate) fn print_default_space<'a>(v: bool) -> &'a str {
1644 if v { "default " } else { "" }
1647 impl clean::GenericArg {
1648 pub(crate) fn print<'a, 'tcx: 'a>(
1650 cx: &'a Context<'tcx>,
1651 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1652 display_fn(move |f| match self {
1653 clean::GenericArg::Lifetime(lt) => fmt::Display::fmt(<.print(), f),
1654 clean::GenericArg::Type(ty) => fmt::Display::fmt(&ty.print(cx), f),
1655 clean::GenericArg::Const(ct) => fmt::Display::fmt(&ct.print(cx.tcx()), f),
1656 clean::GenericArg::Infer => fmt::Display::fmt("_", f),
1661 impl clean::types::Term {
1662 pub(crate) fn print<'a, 'tcx: 'a>(
1664 cx: &'a Context<'tcx>,
1665 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1667 clean::types::Term::Type(ty) => ty.print(cx),
1673 pub(crate) fn display_fn(
1674 f: impl FnOnce(&mut fmt::Formatter<'_>) -> fmt::Result,
1675 ) -> impl fmt::Display {
1676 struct WithFormatter<F>(Cell<Option<F>>);
1678 impl<F> fmt::Display for WithFormatter<F>
1680 F: FnOnce(&mut fmt::Formatter<'_>) -> fmt::Result,
1682 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1683 (self.0.take()).unwrap()(f)
1687 WithFormatter(Cell::new(Some(f)))