1 //! This module implements [RFC 1946]: Intra-rustdoc-links
3 //! [RFC 1946]: https://github.com/rust-lang/rfcs/blob/master/text/1946-intra-rustdoc-links.md
6 use rustc_data_structures::stable_set::FxHashSet;
7 use rustc_errors::{Applicability, DiagnosticBuilder};
8 use rustc_expand::base::SyntaxExtensionKind;
15 use rustc_hir::def_id::{CrateNum, DefId};
17 use rustc_resolve::ParentScope;
18 use rustc_session::lint::{
19 builtin::{BROKEN_INTRA_DOC_LINKS, PRIVATE_INTRA_DOC_LINKS},
22 use rustc_span::hygiene::MacroKind;
23 use rustc_span::symbol::sym;
24 use rustc_span::symbol::Ident;
25 use rustc_span::symbol::Symbol;
26 use rustc_span::DUMMY_SP;
27 use smallvec::{smallvec, SmallVec};
34 use crate::clean::{self, Crate, GetDefId, Item, ItemLink, PrimitiveType};
35 use crate::core::DocContext;
36 use crate::fold::DocFolder;
37 use crate::html::markdown::markdown_links;
38 use crate::passes::Pass;
40 use super::span_of_attrs;
42 crate const COLLECT_INTRA_DOC_LINKS: Pass = Pass {
43 name: "collect-intra-doc-links",
44 run: collect_intra_doc_links,
45 description: "reads a crate's documentation to resolve intra-doc-links",
48 crate fn collect_intra_doc_links(krate: Crate, cx: &DocContext<'_>) -> Crate {
49 LinkCollector::new(cx).fold_crate(krate)
52 /// Top-level errors emitted by this pass.
54 Resolve(Box<ResolutionFailure<'a>>),
55 AnchorFailure(AnchorFailure),
58 impl<'a> From<ResolutionFailure<'a>> for ErrorKind<'a> {
59 fn from(err: ResolutionFailure<'a>) -> Self {
60 ErrorKind::Resolve(box err)
65 /// A link failed to resolve.
66 enum ResolutionFailure<'a> {
67 /// This resolved, but with the wrong namespace.
69 /// `Namespace` is the namespace specified with a disambiguator
70 /// (as opposed to the actual namespace of the `Res`).
71 WrongNamespace(Res, /* disambiguated */ Namespace),
72 /// The link failed to resolve. `resolution_failure` should look to see if there's
73 /// a more helpful error that can be given.
75 /// The scope the link was resolved in.
77 /// If part of the link resolved, this has the `Res`.
79 /// In `[std::io::Error::x]`, `std::io::Error` would be a partial resolution.
80 partial_res: Option<Res>,
81 /// The remaining unresolved path segments.
83 /// In `[std::io::Error::x]`, `x` would be unresolved.
84 unresolved: Cow<'a, str>,
86 /// This happens when rustdoc can't determine the parent scope for an item.
88 /// It is always a bug in rustdoc.
90 /// This link has malformed generic parameters; e.g., the angle brackets are unbalanced.
91 MalformedGenerics(MalformedGenerics),
92 /// Used to communicate that this should be ignored, but shouldn't be reported to the user
94 /// This happens when there is no disambiguator and one of the namespaces
95 /// failed to resolve.
100 enum MalformedGenerics {
101 /// This link has unbalanced angle brackets.
103 /// For example, `Vec<T` should trigger this, as should `Vec<T>>`.
104 UnbalancedAngleBrackets,
105 /// The generics are not attached to a type.
107 /// For example, `<T>` should trigger this.
109 /// This is detected by checking if the path is empty after the generics are stripped.
111 /// The link uses fully-qualified syntax, which is currently unsupported.
113 /// For example, `<Vec as IntoIterator>::into_iter` should trigger this.
115 /// This is detected by checking if ` as ` (the keyword `as` with spaces around it) is inside
117 HasFullyQualifiedSyntax,
118 /// The link has an invalid path separator.
120 /// For example, `Vec:<T>:new()` should trigger this. Note that `Vec:new()` will **not**
121 /// trigger this because it has no generics and thus [`strip_generics_from_path`] will not be
124 /// Note that this will also **not** be triggered if the invalid path separator is inside angle
125 /// brackets because rustdoc mostly ignores what's inside angle brackets (except for
126 /// [`HasFullyQualifiedSyntax`](MalformedGenerics::HasFullyQualifiedSyntax)).
128 /// This is detected by checking if there is a colon followed by a non-colon in the link.
129 InvalidPathSeparator,
130 /// The link has too many angle brackets.
132 /// For example, `Vec<<T>>` should trigger this.
133 TooManyAngleBrackets,
134 /// The link has empty angle brackets.
136 /// For example, `Vec<>` should trigger this.
140 impl ResolutionFailure<'a> {
141 /// This resolved fully (not just partially) but is erroneous for some other reason
143 /// Returns the full resolution of the link, if present.
144 fn full_res(&self) -> Option<Res> {
146 Self::WrongNamespace(res, _) => Some(*res),
153 /// User error: `[std#x#y]` is not valid
155 /// The anchor provided by the user conflicts with Rustdoc's generated anchor.
157 /// This is an unfortunate state of affairs. Not every item that can be
158 /// linked to has its own page; sometimes it is a subheading within a page,
159 /// like for associated items. In those cases, rustdoc uses an anchor to
160 /// link to the subheading. Since you can't have two anchors for the same
161 /// link, Rustdoc disallows having a user-specified anchor.
163 /// Most of the time this is fine, because you can just link to the page of
164 /// the item if you want to provide your own anchor. For primitives, though,
165 /// rustdoc uses the anchor as a side channel to know which page to link to;
166 /// it doesn't show up in the generated link. Ideally, rustdoc would remove
167 /// this limitation, allowing you to link to subheaders on primitives.
168 RustdocAnchorConflict(Res),
171 struct LinkCollector<'a, 'tcx> {
172 cx: &'a DocContext<'tcx>,
173 /// A stack of modules used to decide what scope to resolve in.
175 /// The last module will be used if the parent scope of the current item is
178 /// This is used to store the kind of associated items,
179 /// because `clean` and the disambiguator code expect them to be different.
180 /// See the code for associated items on inherent impls for details.
181 kind_side_channel: Cell<Option<(DefKind, DefId)>>,
184 impl<'a, 'tcx> LinkCollector<'a, 'tcx> {
185 fn new(cx: &'a DocContext<'tcx>) -> Self {
186 LinkCollector { cx, mod_ids: Vec::new(), kind_side_channel: Cell::new(None) }
189 /// Given a full link, parse it as an [enum struct variant].
191 /// In particular, this will return an error whenever there aren't three
192 /// full path segments left in the link.
194 /// [enum struct variant]: hir::VariantData::Struct
197 path_str: &'path str,
199 ) -> Result<(Res, Option<String>), ErrorKind<'path>> {
201 let no_res = || ResolutionFailure::NotResolved {
204 unresolved: path_str.into(),
207 debug!("looking for enum variant {}", path_str);
208 let mut split = path_str.rsplitn(3, "::");
209 let (variant_field_str, variant_field_name) = split
211 .map(|f| (f, Symbol::intern(f)))
212 .expect("fold_item should ensure link is non-empty");
213 let (variant_str, variant_name) =
214 // we're not sure this is a variant at all, so use the full string
215 // If there's no second component, the link looks like `[path]`.
216 // So there's no partial res and we should say the whole link failed to resolve.
217 split.next().map(|f| (f, Symbol::intern(f))).ok_or_else(no_res)?;
220 .map(|f| f.to_owned())
221 // If there's no third component, we saw `[a::b]` before and it failed to resolve.
222 // So there's no partial res.
223 .ok_or_else(no_res)?;
225 .enter_resolver(|resolver| {
226 resolver.resolve_str_path_error(DUMMY_SP, &path, TypeNS, module_id)
229 .unwrap_or(Res::Err);
230 if let Res::Err = ty_res {
231 return Err(no_res().into());
233 let ty_res = ty_res.map_id(|_| panic!("unexpected node_id"));
235 Res::Def(DefKind::Enum, did) => {
240 .flat_map(|imp| cx.tcx.associated_items(*imp).in_definition_order())
241 .any(|item| item.ident.name == variant_name)
243 // This is just to let `fold_item` know that this shouldn't be considered;
244 // it's a bug for the error to make it to the user
245 return Err(ResolutionFailure::Dummy.into());
247 match cx.tcx.type_of(did).kind() {
248 ty::Adt(def, _) if def.is_enum() => {
249 if def.all_fields().any(|item| item.ident.name == variant_field_name) {
253 "variant.{}.field.{}",
254 variant_str, variant_field_name
258 Err(ResolutionFailure::NotResolved {
260 partial_res: Some(Res::Def(DefKind::Enum, def.did)),
261 unresolved: variant_field_str.into(),
269 _ => Err(ResolutionFailure::NotResolved {
271 partial_res: Some(ty_res),
272 unresolved: variant_str.into(),
278 /// Given a primitive type, try to resolve an associated item.
280 /// HACK(jynelson): `item_str` is passed in instead of derived from `item_name` so the
281 /// lifetimes on `&'path` will work.
282 fn resolve_primitive_associated_item(
284 prim_ty: hir::PrimTy,
288 item_str: &'path str,
289 ) -> Result<(Res, Option<String>), ErrorKind<'path>> {
292 PrimitiveType::from_hir(prim_ty)
297 .associated_items(impl_)
298 .find_by_name_and_namespace(
300 Ident::with_dummy_span(item_name),
304 .map(|item| match item.kind {
305 ty::AssocKind::Fn => "method",
306 ty::AssocKind::Const => "associatedconstant",
307 ty::AssocKind::Type => "associatedtype",
311 Res::PrimTy(prim_ty),
312 Some(format!("{}#{}.{}", prim_ty.name(), out, item_str)),
318 "returning primitive error for {}::{} in {} namespace",
323 ResolutionFailure::NotResolved {
325 partial_res: Some(Res::PrimTy(prim_ty)),
326 unresolved: item_str.into(),
332 /// Resolves a string as a macro.
334 /// FIXME(jynelson): Can this be unified with `resolve()`?
339 ) -> Result<Res, ResolutionFailure<'a>> {
341 let path = ast::Path::from_ident(Ident::from_str(path_str));
342 cx.enter_resolver(|resolver| {
343 // FIXME(jynelson): does this really need 3 separate lookups?
344 if let Ok((Some(ext), res)) = resolver.resolve_macro_path(
347 &ParentScope::module(resolver.graph_root(), resolver),
351 if let SyntaxExtensionKind::LegacyBang { .. } = ext.kind {
352 return Ok(res.map_id(|_| panic!("unexpected id")));
355 if let Some(res) = resolver.all_macros().get(&Symbol::intern(path_str)) {
356 return Ok(res.map_id(|_| panic!("unexpected id")));
358 debug!("resolving {} as a macro in the module {:?}", path_str, module_id);
359 if let Ok((_, res)) =
360 resolver.resolve_str_path_error(DUMMY_SP, path_str, MacroNS, module_id)
362 // don't resolve builtins like `#[derive]`
363 if let Res::Def(..) = res {
364 let res = res.map_id(|_| panic!("unexpected node_id"));
368 Err(ResolutionFailure::NotResolved {
371 unresolved: path_str.into(),
376 /// Convenience wrapper around `resolve_str_path_error`.
378 /// This also handles resolving `true` and `false` as booleans.
379 /// NOTE: `resolve_str_path_error` knows only about paths, not about types.
380 /// Associated items will never be resolved by this function.
381 fn resolve_path(&self, path_str: &str, ns: Namespace, module_id: DefId) -> Option<Res> {
382 let result = self.cx.enter_resolver(|resolver| {
383 resolver.resolve_str_path_error(DUMMY_SP, &path_str, ns, module_id)
385 debug!("{} resolved to {:?} in namespace {:?}", path_str, result, ns);
386 match result.map(|(_, res)| res) {
387 // resolver doesn't know about true and false so we'll have to resolve them
389 Ok(Res::Err) | Err(()) => is_bool_value(path_str, ns).map(|(_, res)| res),
390 Ok(res) => Some(res.map_id(|_| panic!("unexpected node_id"))),
394 /// Resolves a string as a path within a particular namespace. Returns an
395 /// optional URL fragment in the case of variants and methods.
398 path_str: &'path str,
401 extra_fragment: &Option<String>,
402 ) -> Result<(Res, Option<String>), ErrorKind<'path>> {
405 if let Some(res) = self.resolve_path(path_str, ns, module_id) {
407 // FIXME(#76467): make this fallthrough to lookup the associated
408 // item a separate function.
409 Res::Def(DefKind::AssocFn | DefKind::AssocConst, _) => {
410 assert_eq!(ns, ValueNS);
412 Res::Def(DefKind::AssocTy, _) => {
413 assert_eq!(ns, TypeNS);
415 Res::Def(DefKind::Variant, _) => {
416 return handle_variant(cx, res, extra_fragment);
418 // Not a trait item; just return what we found.
420 if extra_fragment.is_some() {
421 return Err(ErrorKind::AnchorFailure(
422 AnchorFailure::RustdocAnchorConflict(res),
425 return Ok((res, Some(ty.name_str().to_owned())));
427 Res::Def(DefKind::Mod, _) => {
428 return Ok((res, extra_fragment.clone()));
431 return Ok((res, extra_fragment.clone()));
436 // Try looking for methods and associated items.
437 let mut split = path_str.rsplitn(2, "::");
438 // this can be an `unwrap()` because we ensure the link is never empty
439 let (item_str, item_name) = split.next().map(|i| (i, Symbol::intern(i))).unwrap();
440 let path_root = split
442 .map(|f| f.to_owned())
443 // If there's no `::`, it's not an associated item.
444 // So we can be sure that `rustc_resolve` was accurate when it said it wasn't resolved.
446 debug!("found no `::`, assumming {} was correctly not in scope", item_name);
447 ResolutionFailure::NotResolved {
450 unresolved: item_str.into(),
454 // FIXME: are these both necessary?
455 let ty_res = if let Some(ty_res) = resolve_primitive(&path_root, TypeNS)
457 .or_else(|| self.resolve_path(&path_root, TypeNS, module_id))
461 // FIXME: this is duplicated on the end of this function.
462 return if ns == Namespace::ValueNS {
463 self.variant_field(path_str, module_id)
465 Err(ResolutionFailure::NotResolved {
468 unresolved: path_root.into(),
474 let res = match ty_res {
475 Res::PrimTy(prim) => Some(
476 self.resolve_primitive_associated_item(prim, ns, module_id, item_name, item_str),
483 | DefKind::ForeignTy,
486 debug!("looking for associated item named {} for item {:?}", item_name, did);
487 // Checks if item_name belongs to `impl SomeItem`
493 cx.tcx.associated_items(imp).find_by_name_and_namespace(
495 Ident::with_dummy_span(item_name),
500 .map(|item| (item.kind, item.def_id))
501 // There should only ever be one associated item that matches from any inherent impl
503 // Check if item_name belongs to `impl SomeTrait for SomeItem`
504 // FIXME(#74563): This gives precedence to `impl SomeItem`:
505 // Although having both would be ambiguous, use impl version for compatibility's sake.
506 // To handle that properly resolve() would have to support
507 // something like [`ambi_fn`](<SomeStruct as SomeTrait>::ambi_fn)
510 resolve_associated_trait_item(did, module_id, item_name, ns, &self.cx);
511 debug!("got associated item kind {:?}", kind);
515 if let Some((kind, id)) = assoc_item {
516 let out = match kind {
517 ty::AssocKind::Fn => "method",
518 ty::AssocKind::Const => "associatedconstant",
519 ty::AssocKind::Type => "associatedtype",
521 Some(if extra_fragment.is_some() {
522 Err(ErrorKind::AnchorFailure(AnchorFailure::RustdocAnchorConflict(ty_res)))
524 // HACK(jynelson): `clean` expects the type, not the associated item
525 // but the disambiguator logic expects the associated item.
526 // Store the kind in a side channel so that only the disambiguator logic looks at it.
527 self.kind_side_channel.set(Some((kind.as_def_kind(), id)));
528 Ok((ty_res, Some(format!("{}.{}", out, item_str))))
530 } else if ns == Namespace::ValueNS {
531 debug!("looking for variants or fields named {} for {:?}", item_name, did);
532 // FIXME(jynelson): why is this different from
534 match cx.tcx.type_of(did).kind() {
536 let field = if def.is_enum() {
537 def.all_fields().find(|item| item.ident.name == item_name)
539 def.non_enum_variant()
542 .find(|item| item.ident.name == item_name)
545 if extra_fragment.is_some() {
554 Err(ErrorKind::AnchorFailure(
555 AnchorFailure::RustdocAnchorConflict(res),
562 if def.is_enum() { "variant" } else { "structfield" },
575 Res::Def(DefKind::Trait, did) => cx
577 .associated_items(did)
578 .find_by_name_and_namespace(cx.tcx, Ident::with_dummy_span(item_name), ns, did)
580 let kind = match item.kind {
581 ty::AssocKind::Const => "associatedconstant",
582 ty::AssocKind::Type => "associatedtype",
583 ty::AssocKind::Fn => {
584 if item.defaultness.has_value() {
592 if extra_fragment.is_some() {
593 Err(ErrorKind::AnchorFailure(AnchorFailure::RustdocAnchorConflict(ty_res)))
595 let res = Res::Def(item.kind.as_def_kind(), item.def_id);
596 Ok((res, Some(format!("{}.{}", kind, item_str))))
601 res.unwrap_or_else(|| {
602 if ns == Namespace::ValueNS {
603 self.variant_field(path_str, module_id)
605 Err(ResolutionFailure::NotResolved {
607 partial_res: Some(ty_res),
608 unresolved: item_str.into(),
615 /// Used for reporting better errors.
617 /// Returns whether the link resolved 'fully' in another namespace.
618 /// 'fully' here means that all parts of the link resolved, not just some path segments.
619 /// This returns the `Res` even if it was erroneous for some reason
620 /// (such as having invalid URL fragments or being in the wrong namespace).
626 extra_fragment: &Option<String>,
628 // resolve() can't be used for macro namespace
629 let result = match ns {
630 Namespace::MacroNS => self.resolve_macro(path_str, module_id).map_err(ErrorKind::from),
631 Namespace::TypeNS | Namespace::ValueNS => {
632 self.resolve(path_str, ns, module_id, extra_fragment).map(|(res, _)| res)
636 let res = match result {
637 Ok(res) => Some(res),
638 Err(ErrorKind::Resolve(box kind)) => kind.full_res(),
639 Err(ErrorKind::AnchorFailure(AnchorFailure::RustdocAnchorConflict(res))) => Some(res),
640 Err(ErrorKind::AnchorFailure(AnchorFailure::MultipleAnchors)) => None,
642 self.kind_side_channel.take().map(|(kind, id)| Res::Def(kind, id)).or(res)
646 /// Look to see if a resolved item has an associated item named `item_name`.
648 /// Given `[std::io::Error::source]`, where `source` is unresolved, this would
649 /// find `std::error::Error::source` and return
650 /// `<io::Error as error::Error>::source`.
651 fn resolve_associated_trait_item(
657 ) -> Option<(ty::AssocKind, DefId)> {
658 let ty = cx.tcx.type_of(did);
659 // First consider blanket impls: `impl From<T> for T`
660 let implicit_impls = crate::clean::get_auto_trait_and_blanket_impls(cx, ty, did);
661 let mut candidates: Vec<_> = implicit_impls
662 .flat_map(|impl_outer| {
663 match impl_outer.kind {
664 clean::ImplItem(impl_) => {
665 debug!("considering auto or blanket impl for trait {:?}", impl_.trait_);
666 // Give precedence to methods that were overridden
667 if !impl_.provided_trait_methods.contains(&*item_name.as_str()) {
668 let mut items = impl_.items.into_iter().filter_map(|assoc| {
669 if assoc.name.as_deref() != Some(&*item_name.as_str()) {
675 .expect("inner items for a trait should be associated items");
676 if kind.namespace() != ns {
680 trace!("considering associated item {:?}", assoc.kind);
681 // We have a slight issue: normal methods come from `clean` types,
682 // but provided methods come directly from `tcx`.
683 // Fortunately, we don't need the whole method, we just need to know
684 // what kind of associated item it is.
685 Some((kind, assoc.def_id))
687 let assoc = items.next();
688 debug_assert_eq!(items.count(), 0);
691 // These are provided methods or default types:
695 // fn has_default() -> A { 0 }
698 let trait_ = impl_.trait_.unwrap().def_id().unwrap();
700 .associated_items(trait_)
701 .find_by_name_and_namespace(
703 Ident::with_dummy_span(item_name),
707 .map(|assoc| (assoc.kind, assoc.def_id))
710 _ => panic!("get_impls returned something that wasn't an impl"),
715 // Next consider explicit impls: `impl MyTrait for MyType`
716 // Give precedence to inherent impls.
717 if candidates.is_empty() {
718 let traits = traits_implemented_by(cx, did, module);
719 debug!("considering traits {:?}", traits);
720 candidates.extend(traits.iter().filter_map(|&trait_| {
722 .associated_items(trait_)
723 .find_by_name_and_namespace(cx.tcx, Ident::with_dummy_span(item_name), ns, trait_)
724 .map(|assoc| (assoc.kind, assoc.def_id))
727 // FIXME(#74563): warn about ambiguity
728 debug!("the candidates were {:?}", candidates);
732 /// Given a type, return all traits in scope in `module` implemented by that type.
734 /// NOTE: this cannot be a query because more traits could be available when more crates are compiled!
735 /// So it is not stable to serialize cross-crate.
736 fn traits_implemented_by(cx: &DocContext<'_>, type_: DefId, module: DefId) -> FxHashSet<DefId> {
737 let mut cache = cx.module_trait_cache.borrow_mut();
738 let in_scope_traits = cache.entry(module).or_insert_with(|| {
739 cx.enter_resolver(|resolver| {
740 resolver.traits_in_scope(module).into_iter().map(|candidate| candidate.def_id).collect()
744 let ty = cx.tcx.type_of(type_);
745 let iter = in_scope_traits.iter().flat_map(|&trait_| {
746 trace!("considering explicit impl for trait {:?}", trait_);
748 // Look at each trait implementation to see if it's an impl for `did`
749 cx.tcx.find_map_relevant_impl(trait_, ty, |impl_| {
750 let trait_ref = cx.tcx.impl_trait_ref(impl_).expect("this is not an inherent impl");
751 // Check if these are the same type.
752 let impl_type = trait_ref.self_ty();
754 "comparing type {} with kind {:?} against type {:?}",
759 // Fast path: if this is a primitive simple `==` will work
760 let saw_impl = impl_type == ty
761 || match impl_type.kind() {
762 // Check if these are the same def_id
764 debug!("adt def_id: {:?}", def.did);
767 ty::Foreign(def_id) => *def_id == type_,
771 if saw_impl { Some(trait_) } else { None }
777 /// Check for resolve collisions between a trait and its derive.
779 /// These are common and we should just resolve to the trait in that case.
780 fn is_derive_trait_collision<T>(ns: &PerNS<Result<(Res, T), ResolutionFailure<'_>>>) -> bool {
781 matches!(*ns, PerNS {
782 type_ns: Ok((Res::Def(DefKind::Trait, _), _)),
783 macro_ns: Ok((Res::Def(DefKind::Macro(MacroKind::Derive), _), _)),
788 impl<'a, 'tcx> DocFolder for LinkCollector<'a, 'tcx> {
789 fn fold_item(&mut self, mut item: Item) -> Option<Item> {
790 use rustc_middle::ty::DefIdTree;
792 let parent_node = if item.is_fake() {
793 // FIXME: is this correct?
795 // If we're documenting the crate root itself, it has no parent. Use the root instead.
796 } else if item.def_id.is_top_level_module() {
799 let mut current = item.def_id;
800 // The immediate parent might not always be a module.
801 // Find the first parent which is.
803 if let Some(parent) = self.cx.tcx.parent(current) {
804 if self.cx.tcx.def_kind(parent) == DefKind::Mod {
810 "{:?} has no parent (kind={:?}, original was {:?})",
812 self.cx.tcx.def_kind(current),
820 if parent_node.is_some() {
821 trace!("got parent node for {:?} {:?}, id {:?}", item.type_(), item.name, item.def_id);
824 // find item's parent to resolve `Self` in item's docs below
825 debug!("looking for the `Self` type");
826 let self_id = if item.is_fake() {
829 self.cx.tcx.def_kind(item.def_id),
836 self.cx.tcx.parent(item.def_id)
837 // HACK(jynelson): `clean` marks associated types as `TypedefItem`, not as `AssocTypeItem`.
838 // Fixing this breaks `fn render_deref_methods`.
839 // As a workaround, see if the parent of the item is an `impl`; if so this must be an associated item,
840 // regardless of what rustdoc wants to call it.
841 } else if let Some(parent) = self.cx.tcx.parent(item.def_id) {
842 let parent_kind = self.cx.tcx.def_kind(parent);
843 Some(if parent_kind == DefKind::Impl { parent } else { item.def_id })
848 // FIXME(jynelson): this shouldn't go through stringification, rustdoc should just use the DefId directly
849 let self_name = self_id.and_then(|self_id| {
851 if matches!(self.cx.tcx.def_kind(self_id), DefKind::Impl) {
852 // using `ty.to_string()` (or any variant) has issues with raw idents
853 let ty = self.cx.tcx.type_of(self_id);
854 let name = match ty.kind() {
855 TyKind::Adt(def, _) => Some(self.cx.tcx.item_name(def.did).to_string()),
856 other if other.is_primitive() => Some(ty.to_string()),
859 debug!("using type_of(): {:?}", name);
862 let name = self.cx.tcx.opt_item_name(self_id).map(|sym| sym.to_string());
863 debug!("using item_name(): {:?}", name);
868 if item.is_mod() && item.attrs.inner_docs {
869 self.mod_ids.push(item.def_id);
872 // We want to resolve in the lexical scope of the documentation.
873 // In the presence of re-exports, this is not the same as the module of the item.
874 // Rather than merging all documentation into one, resolve it one attribute at a time
875 // so we know which module it came from.
876 let mut attrs = item.attrs.doc_strings.iter().peekable();
877 while let Some(attr) = attrs.next() {
878 // `collapse_docs` does not have the behavior we want:
879 // we want `///` and `#[doc]` to count as the same attribute,
880 // but currently it will treat them as separate.
881 // As a workaround, combine all attributes with the same parent module into the same attribute.
882 let mut combined_docs = attr.doc.clone();
885 Some(next) if next.parent_module == attr.parent_module => {
886 combined_docs.push('\n');
887 combined_docs.push_str(&attrs.next().unwrap().doc);
892 debug!("combined_docs={}", combined_docs);
894 let (krate, parent_node) = if let Some(id) = attr.parent_module {
895 trace!("docs {:?} came from {:?}", attr.doc, id);
898 trace!("no parent found for {:?}", attr.doc);
899 (item.def_id.krate, parent_node)
901 // NOTE: if there are links that start in one crate and end in another, this will not resolve them.
902 // This is a degenerate case and it's not supported by rustdoc.
903 for (ori_link, link_range) in markdown_links(&combined_docs) {
904 let link = self.resolve_link(
913 if let Some(link) = link {
914 item.attrs.links.push(link);
919 Some(if item.is_mod() {
920 if !item.attrs.inner_docs {
921 self.mod_ids.push(item.def_id);
924 let ret = self.fold_item_recur(item);
928 self.fold_item_recur(item)
933 impl LinkCollector<'_, '_> {
934 /// This is the entry point for resolving an intra-doc link.
936 /// FIXME(jynelson): this is way too many arguments
941 self_name: &Option<String>,
942 parent_node: Option<DefId>,
945 link_range: Option<Range<usize>>,
946 ) -> Option<ItemLink> {
947 trace!("considering link '{}'", ori_link);
949 // Bail early for real links.
950 if ori_link.contains('/') {
954 // [] is mostly likely not supposed to be a link
955 if ori_link.is_empty() {
960 let link = ori_link.replace("`", "");
961 let parts = link.split('#').collect::<Vec<_>>();
962 let (link, extra_fragment) = if parts.len() > 2 {
963 anchor_failure(cx, &item, &link, dox, link_range, AnchorFailure::MultipleAnchors);
965 } else if parts.len() == 2 {
966 if parts[0].trim().is_empty() {
967 // This is an anchor to an element of the current page, nothing to do in here!
970 (parts[0], Some(parts[1].to_owned()))
975 // Parse and strip the disambiguator from the link, if present.
976 let (mut path_str, disambiguator) = if let Ok((d, path)) = Disambiguator::from_str(&link) {
977 (path.trim(), Some(d))
982 if path_str.contains(|ch: char| !(ch.is_alphanumeric() || ":_<>, !".contains(ch))) {
986 // We stripped `()` and `!` when parsing the disambiguator.
987 // Add them back to be displayed, but not prefix disambiguators.
989 disambiguator.map(|d| d.display_for(path_str)).unwrap_or_else(|| path_str.to_owned());
991 // In order to correctly resolve intra-doc-links we need to
992 // pick a base AST node to work from. If the documentation for
993 // this module came from an inner comment (//!) then we anchor
994 // our name resolution *inside* the module. If, on the other
995 // hand it was an outer comment (///) then we anchor the name
996 // resolution in the parent module on the basis that the names
997 // used are more likely to be intended to be parent names. For
998 // this, we set base_node to None for inner comments since
999 // we've already pushed this node onto the resolution stack but
1000 // for outer comments we explicitly try and resolve against the
1001 // parent_node first.
1002 let base_node = if item.is_mod() && item.attrs.inner_docs {
1003 self.mod_ids.last().copied()
1008 let mut module_id = if let Some(id) = base_node {
1012 debug!("attempting to resolve item without parent module: {}", path_str);
1013 let err_kind = ResolutionFailure::NoParentItem.into();
1021 smallvec![err_kind],
1027 // replace `Self` with suitable item's parent name
1028 if path_str.starts_with("Self::") {
1029 if let Some(ref name) = self_name {
1030 resolved_self = format!("{}::{}", name, &path_str[6..]);
1031 path_str = &resolved_self;
1033 } else if path_str.starts_with("crate::") {
1034 use rustc_span::def_id::CRATE_DEF_INDEX;
1036 // HACK(jynelson): rustc_resolve thinks that `crate` is the crate currently being documented.
1037 // But rustdoc wants it to mean the crate this item was originally present in.
1038 // To work around this, remove it and resolve relative to the crate root instead.
1039 // HACK(jynelson)(2): If we just strip `crate::` then suddenly primitives become ambiguous
1040 // (consider `crate::char`). Instead, change it to `self::`. This works because 'self' is now the crate root.
1041 // FIXME(#78696): This doesn't always work.
1042 resolved_self = format!("self::{}", &path_str["crate::".len()..]);
1043 path_str = &resolved_self;
1044 module_id = DefId { krate, index: CRATE_DEF_INDEX };
1047 // Strip generics from the path.
1048 let stripped_path_string;
1049 if path_str.contains(['<', '>'].as_slice()) {
1050 stripped_path_string = match strip_generics_from_path(path_str) {
1053 debug!("link has malformed generics: {}", path_str);
1061 smallvec![err_kind],
1066 path_str = &stripped_path_string;
1068 // Sanity check to make sure we don't have any angle brackets after stripping generics.
1069 assert!(!path_str.contains(['<', '>'].as_slice()));
1071 // The link is not an intra-doc link if it still contains commas or spaces after
1072 // stripping generics.
1073 if path_str.contains([',', ' '].as_slice()) {
1077 let (mut res, mut fragment) = self.resolve_with_disambiguator(
1088 // Check for a primitive which might conflict with a module
1089 // Report the ambiguity and require that the user specify which one they meant.
1090 // FIXME: could there ever be a primitive not in the type namespace?
1093 None | Some(Disambiguator::Namespace(Namespace::TypeNS) | Disambiguator::Primitive)
1094 ) && !matches!(res, Res::PrimTy(_))
1096 if let Some((path, prim)) = resolve_primitive(path_str, TypeNS) {
1098 if matches!(disambiguator, Some(Disambiguator::Primitive)) {
1099 if fragment.is_some() {
1106 AnchorFailure::RustdocAnchorConflict(prim),
1111 fragment = Some(path.as_str().to_string());
1113 // `[char]` when a `char` module is in scope
1114 let candidates = vec![res, prim];
1115 ambiguity_error(cx, &item, path_str, dox, link_range, candidates);
1121 let report_mismatch = |specified: Disambiguator, resolved: Disambiguator| {
1122 // The resolved item did not match the disambiguator; give a better error than 'not found'
1123 let msg = format!("incompatible link kind for `{}`", path_str);
1124 let callback = |diag: &mut DiagnosticBuilder<'_>, sp| {
1126 "this link resolved to {} {}, which is not {} {}",
1129 specified.article(),
1133 suggest_disambiguator(resolved, diag, path_str, dox, sp, &link_range);
1135 report_diagnostic(cx, BROKEN_INTRA_DOC_LINKS, &msg, &item, dox, &link_range, callback);
1137 if let Res::PrimTy(..) = res {
1138 match disambiguator {
1139 Some(Disambiguator::Primitive | Disambiguator::Namespace(_)) | None => {
1140 Some(ItemLink { link: ori_link, link_text, did: None, fragment })
1143 report_mismatch(other, Disambiguator::Primitive);
1148 debug!("intra-doc link to {} resolved to {:?}", path_str, res);
1150 // Disallow e.g. linking to enums with `struct@`
1151 if let Res::Def(kind, _) = res {
1152 debug!("saw kind {:?} with disambiguator {:?}", kind, disambiguator);
1153 match (self.kind_side_channel.take().map(|(kind, _)| kind).unwrap_or(kind), disambiguator) {
1154 | (DefKind::Const | DefKind::ConstParam | DefKind::AssocConst | DefKind::AnonConst, Some(Disambiguator::Kind(DefKind::Const)))
1155 // NOTE: this allows 'method' to mean both normal functions and associated functions
1156 // This can't cause ambiguity because both are in the same namespace.
1157 | (DefKind::Fn | DefKind::AssocFn, Some(Disambiguator::Kind(DefKind::Fn)))
1158 // These are namespaces; allow anything in the namespace to match
1159 | (_, Some(Disambiguator::Namespace(_)))
1160 // If no disambiguator given, allow anything
1162 // All of these are valid, so do nothing
1164 (actual, Some(Disambiguator::Kind(expected))) if actual == expected => {}
1165 (_, Some(specified @ Disambiguator::Kind(_) | specified @ Disambiguator::Primitive)) => {
1166 report_mismatch(specified, Disambiguator::Kind(kind));
1172 // item can be non-local e.g. when using #[doc(primitive = "pointer")]
1173 if let Some((src_id, dst_id)) = res
1175 .and_then(|def_id| def_id.as_local())
1176 .and_then(|dst_id| item.def_id.as_local().map(|src_id| (src_id, dst_id)))
1178 use rustc_hir::def_id::LOCAL_CRATE;
1180 let hir_src = self.cx.tcx.hir().local_def_id_to_hir_id(src_id);
1181 let hir_dst = self.cx.tcx.hir().local_def_id_to_hir_id(dst_id);
1183 if self.cx.tcx.privacy_access_levels(LOCAL_CRATE).is_exported(hir_src)
1184 && !self.cx.tcx.privacy_access_levels(LOCAL_CRATE).is_exported(hir_dst)
1186 privacy_error(cx, &item, &path_str, dox, link_range);
1189 let id = clean::register_res(cx, res);
1190 Some(ItemLink { link: ori_link, link_text, did: Some(id), fragment })
1194 /// After parsing the disambiguator, resolve the main part of the link.
1195 // FIXME(jynelson): wow this is just so much
1196 fn resolve_with_disambiguator(
1198 disambiguator: Option<Disambiguator>,
1203 extra_fragment: Option<String>,
1205 link_range: Option<Range<usize>>,
1206 ) -> Option<(Res, Option<String>)> {
1207 match disambiguator.map(Disambiguator::ns) {
1208 Some(ns @ (ValueNS | TypeNS)) => {
1209 match self.resolve(path_str, ns, base_node, &extra_fragment) {
1210 Ok(res) => Some(res),
1211 Err(ErrorKind::Resolve(box mut kind)) => {
1212 // We only looked in one namespace. Try to give a better error if possible.
1213 if kind.full_res().is_none() {
1214 let other_ns = if ns == ValueNS { TypeNS } else { ValueNS };
1215 // FIXME: really it should be `resolution_failure` that does this, not `resolve_with_disambiguator`
1216 // See https://github.com/rust-lang/rust/pull/76955#discussion_r493953382 for a good approach
1217 for &new_ns in &[other_ns, MacroNS] {
1218 if let Some(res) = self.check_full_res(
1224 kind = ResolutionFailure::WrongNamespace(res, ns);
1238 // This could just be a normal link or a broken link
1239 // we could potentially check if something is
1240 // "intra-doc-link-like" and warn in that case.
1243 Err(ErrorKind::AnchorFailure(msg)) => {
1244 anchor_failure(self.cx, &item, &ori_link, dox, link_range, msg);
1251 let mut candidates = PerNS {
1253 .resolve_macro(path_str, base_node)
1254 .map(|res| (res, extra_fragment.clone())),
1255 type_ns: match self.resolve(path_str, TypeNS, base_node, &extra_fragment) {
1257 debug!("got res in TypeNS: {:?}", res);
1260 Err(ErrorKind::AnchorFailure(msg)) => {
1261 anchor_failure(self.cx, &item, ori_link, dox, link_range, msg);
1264 Err(ErrorKind::Resolve(box kind)) => Err(kind),
1266 value_ns: match self.resolve(path_str, ValueNS, base_node, &extra_fragment) {
1268 Err(ErrorKind::AnchorFailure(msg)) => {
1269 anchor_failure(self.cx, &item, ori_link, dox, link_range, msg);
1272 Err(ErrorKind::Resolve(box kind)) => Err(kind),
1274 .and_then(|(res, fragment)| {
1275 // Constructors are picked up in the type namespace.
1277 Res::Def(DefKind::Ctor(..), _) | Res::SelfCtor(..) => {
1278 Err(ResolutionFailure::WrongNamespace(res, TypeNS))
1280 _ => match (fragment, extra_fragment) {
1281 (Some(fragment), Some(_)) => {
1282 // Shouldn't happen but who knows?
1283 Ok((res, Some(fragment)))
1285 (fragment, None) | (None, fragment) => Ok((res, fragment)),
1291 let len = candidates.iter().filter(|res| res.is_ok()).count();
1301 candidates.into_iter().filter_map(|res| res.err()).collect(),
1303 // this could just be a normal link
1308 Some(candidates.into_iter().filter_map(|res| res.ok()).next().unwrap())
1309 } else if len == 2 && is_derive_trait_collision(&candidates) {
1310 Some(candidates.type_ns.unwrap())
1312 if is_derive_trait_collision(&candidates) {
1313 candidates.macro_ns = Err(ResolutionFailure::Dummy);
1315 // If we're reporting an ambiguity, don't mention the namespaces that failed
1316 let candidates = candidates.map(|candidate| candidate.ok().map(|(res, _)| res));
1323 candidates.present_items().collect(),
1329 match self.resolve_macro(path_str, base_node) {
1330 Ok(res) => Some((res, extra_fragment)),
1332 // `resolve_macro` only looks in the macro namespace. Try to give a better error if possible.
1333 for &ns in &[TypeNS, ValueNS] {
1335 self.check_full_res(ns, path_str, base_node, &extra_fragment)
1337 kind = ResolutionFailure::WrongNamespace(res, MacroNS);
1358 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
1359 /// Disambiguators for a link.
1360 enum Disambiguator {
1363 /// This is buggy, see <https://github.com/rust-lang/rust/pull/77875#discussion_r503583103>
1365 /// `struct@` or `f()`
1368 Namespace(Namespace),
1371 impl Disambiguator {
1372 /// The text that should be displayed when the path is rendered as HTML.
1374 /// NOTE: `path` is not the original link given by the user, but a name suitable for passing to `resolve`.
1375 fn display_for(&self, path: &str) -> String {
1377 // FIXME: this will have different output if the user had `m!()` originally.
1378 Self::Kind(DefKind::Macro(MacroKind::Bang)) => format!("{}!", path),
1379 Self::Kind(DefKind::Fn) => format!("{}()", path),
1380 _ => path.to_owned(),
1384 /// Given a link, parse and return `(disambiguator, path_str)`
1385 fn from_str(link: &str) -> Result<(Self, &str), ()> {
1386 use Disambiguator::{Kind, Namespace as NS, Primitive};
1388 let find_suffix = || {
1390 ("!()", DefKind::Macro(MacroKind::Bang)),
1391 ("()", DefKind::Fn),
1392 ("!", DefKind::Macro(MacroKind::Bang)),
1394 for &(suffix, kind) in &suffixes {
1395 if link.ends_with(suffix) {
1396 return Ok((Kind(kind), link.trim_end_matches(suffix)));
1402 if let Some(idx) = link.find('@') {
1403 let (prefix, rest) = link.split_at(idx);
1404 let d = match prefix {
1405 "struct" => Kind(DefKind::Struct),
1406 "enum" => Kind(DefKind::Enum),
1407 "trait" => Kind(DefKind::Trait),
1408 "union" => Kind(DefKind::Union),
1409 "module" | "mod" => Kind(DefKind::Mod),
1410 "const" | "constant" => Kind(DefKind::Const),
1411 "static" => Kind(DefKind::Static),
1412 "function" | "fn" | "method" => Kind(DefKind::Fn),
1413 "derive" => Kind(DefKind::Macro(MacroKind::Derive)),
1414 "type" => NS(Namespace::TypeNS),
1415 "value" => NS(Namespace::ValueNS),
1416 "macro" => NS(Namespace::MacroNS),
1417 "prim" | "primitive" => Primitive,
1418 _ => return find_suffix(),
1426 /// WARNING: panics on `Res::Err`
1427 fn from_res(res: Res) -> Self {
1429 Res::Def(kind, _) => Disambiguator::Kind(kind),
1430 Res::PrimTy(_) => Disambiguator::Primitive,
1431 _ => Disambiguator::Namespace(res.ns().expect("can't call `from_res` on Res::err")),
1435 /// Used for error reporting.
1436 fn suggestion(self) -> Suggestion {
1437 let kind = match self {
1438 Disambiguator::Primitive => return Suggestion::Prefix("prim"),
1439 Disambiguator::Kind(kind) => kind,
1440 Disambiguator::Namespace(_) => panic!("display_for cannot be used on namespaces"),
1442 if kind == DefKind::Macro(MacroKind::Bang) {
1443 return Suggestion::Macro;
1444 } else if kind == DefKind::Fn || kind == DefKind::AssocFn {
1445 return Suggestion::Function;
1448 let prefix = match kind {
1449 DefKind::Struct => "struct",
1450 DefKind::Enum => "enum",
1451 DefKind::Trait => "trait",
1452 DefKind::Union => "union",
1453 DefKind::Mod => "mod",
1454 DefKind::Const | DefKind::ConstParam | DefKind::AssocConst | DefKind::AnonConst => {
1457 DefKind::Static => "static",
1458 DefKind::Macro(MacroKind::Derive) => "derive",
1459 // Now handle things that don't have a specific disambiguator
1462 .expect("tried to calculate a disambiguator for a def without a namespace?")
1464 Namespace::TypeNS => "type",
1465 Namespace::ValueNS => "value",
1466 Namespace::MacroNS => "macro",
1470 Suggestion::Prefix(prefix)
1473 fn ns(self) -> Namespace {
1475 Self::Namespace(n) => n,
1477 k.ns().expect("only DefKinds with a valid namespace can be disambiguators")
1479 Self::Primitive => TypeNS,
1483 fn article(self) -> &'static str {
1485 Self::Namespace(_) => panic!("article() doesn't make sense for namespaces"),
1486 Self::Kind(k) => k.article(),
1487 Self::Primitive => "a",
1491 fn descr(self) -> &'static str {
1493 Self::Namespace(n) => n.descr(),
1494 // HACK(jynelson): by looking at the source I saw the DefId we pass
1495 // for `expected.descr()` doesn't matter, since it's not a crate
1496 Self::Kind(k) => k.descr(DefId::local(hir::def_id::DefIndex::from_usize(0))),
1497 Self::Primitive => "builtin type",
1502 /// A suggestion to show in a diagnostic.
1505 Prefix(&'static str),
1513 fn descr(&self) -> Cow<'static, str> {
1515 Self::Prefix(x) => format!("prefix with `{}@`", x).into(),
1516 Self::Function => "add parentheses".into(),
1517 Self::Macro => "add an exclamation mark".into(),
1521 fn as_help(&self, path_str: &str) -> String {
1522 // FIXME: if this is an implied shortcut link, it's bad style to suggest `@`
1524 Self::Prefix(prefix) => format!("{}@{}", prefix, path_str),
1525 Self::Function => format!("{}()", path_str),
1526 Self::Macro => format!("{}!", path_str),
1531 /// Reports a diagnostic for an intra-doc link.
1533 /// If no link range is provided, or the source span of the link cannot be determined, the span of
1534 /// the entire documentation block is used for the lint. If a range is provided but the span
1535 /// calculation fails, a note is added to the diagnostic pointing to the link in the markdown.
1537 /// The `decorate` callback is invoked in all cases to allow further customization of the
1538 /// diagnostic before emission. If the span of the link was able to be determined, the second
1539 /// parameter of the callback will contain it, and the primary span of the diagnostic will be set
1541 fn report_diagnostic(
1542 cx: &DocContext<'_>,
1543 lint: &'static Lint,
1547 link_range: &Option<Range<usize>>,
1548 decorate: impl FnOnce(&mut DiagnosticBuilder<'_>, Option<rustc_span::Span>),
1550 let hir_id = match cx.as_local_hir_id(item.def_id) {
1551 Some(hir_id) => hir_id,
1553 // If non-local, no need to check anything.
1554 info!("ignoring warning from parent crate: {}", msg);
1559 let attrs = &item.attrs;
1560 let sp = span_of_attrs(attrs).unwrap_or(item.source.span());
1562 cx.tcx.struct_span_lint_hir(lint, hir_id, sp, |lint| {
1563 let mut diag = lint.build(msg);
1565 let span = link_range
1567 .and_then(|range| super::source_span_for_markdown_range(cx, dox, range, attrs));
1569 if let Some(link_range) = link_range {
1570 if let Some(sp) = span {
1573 // blah blah blah\nblah\nblah [blah] blah blah\nblah blah
1576 // last_new_line_offset
1577 let last_new_line_offset = dox[..link_range.start].rfind('\n').map_or(0, |n| n + 1);
1578 let line = dox[last_new_line_offset..].lines().next().unwrap_or("");
1580 // Print the line containing the `link_range` and manually mark it with '^'s.
1582 "the link appears in this line:\n\n{line}\n\
1583 {indicator: <before$}{indicator:^<found$}",
1586 before = link_range.start - last_new_line_offset,
1587 found = link_range.len(),
1592 decorate(&mut diag, span);
1598 /// Reports a link that failed to resolve.
1600 /// This also tries to resolve any intermediate path segments that weren't
1601 /// handled earlier. For example, if passed `Item::Crate(std)` and `path_str`
1602 /// `std::io::Error::x`, this will resolve `std::io::Error`.
1603 fn resolution_failure(
1604 collector: &LinkCollector<'_, '_>,
1607 disambiguator: Option<Disambiguator>,
1609 link_range: Option<Range<usize>>,
1610 kinds: SmallVec<[ResolutionFailure<'_>; 3]>,
1614 BROKEN_INTRA_DOC_LINKS,
1615 &format!("unresolved link to `{}`", path_str),
1620 let item = |res: Res| {
1624 collector.cx.tcx.item_name(res.def_id()).to_string()
1627 let assoc_item_not_allowed = |res: Res| {
1628 let def_id = res.def_id();
1629 let name = collector.cx.tcx.item_name(def_id);
1631 "`{}` is {} {}, not a module or type, and cannot have associated items",
1637 // ignore duplicates
1638 let mut variants_seen = SmallVec::<[_; 3]>::new();
1639 for mut failure in kinds {
1640 let variant = std::mem::discriminant(&failure);
1641 if variants_seen.contains(&variant) {
1644 variants_seen.push(variant);
1646 if let ResolutionFailure::NotResolved { module_id, partial_res, unresolved } =
1651 let module_id = *module_id;
1652 // FIXME(jynelson): this might conflict with my `Self` fix in #76467
1653 // FIXME: maybe use itertools `collect_tuple` instead?
1654 fn split(path: &str) -> Option<(&str, &str)> {
1655 let mut splitter = path.rsplitn(2, "::");
1656 splitter.next().and_then(|right| splitter.next().map(|left| (left, right)))
1659 // Check if _any_ parent of the path gets resolved.
1660 // If so, report it and say the first which failed; if not, say the first path segment didn't resolve.
1661 let mut name = path_str;
1663 let (start, end) = if let Some(x) = split(name) {
1666 // avoid bug that marked [Quux::Z] as missing Z, not Quux
1667 if partial_res.is_none() {
1668 *unresolved = name.into();
1673 for &ns in &[TypeNS, ValueNS, MacroNS] {
1675 collector.check_full_res(ns, &start, module_id, &None)
1677 debug!("found partial_res={:?}", res);
1678 *partial_res = Some(res);
1679 *unresolved = end.into();
1683 *unresolved = end.into();
1686 let last_found_module = match *partial_res {
1687 Some(Res::Def(DefKind::Mod, id)) => Some(id),
1688 None => Some(module_id),
1691 // See if this was a module: `[path]` or `[std::io::nope]`
1692 if let Some(module) = last_found_module {
1693 let note = if partial_res.is_some() {
1694 // Part of the link resolved; e.g. `std::io::nonexistent`
1695 let module_name = collector.cx.tcx.item_name(module);
1696 format!("no item named `{}` in module `{}`", unresolved, module_name)
1698 // None of the link resolved; e.g. `Notimported`
1699 format!("no item named `{}` in scope", unresolved)
1701 if let Some(span) = sp {
1702 diag.span_label(span, ¬e);
1707 // If the link has `::` in it, assume it was meant to be an intra-doc link.
1708 // Otherwise, the `[]` might be unrelated.
1709 // FIXME: don't show this for autolinks (`<>`), `()` style links, or reference links
1710 if !path_str.contains("::") {
1711 diag.help(r#"to escape `[` and `]` characters, add '\' before them like `\[` or `\]`"#);
1717 // Otherwise, it must be an associated item or variant
1718 let res = partial_res.expect("None case was handled by `last_found_module`");
1719 let diagnostic_name;
1720 let (kind, name) = match res {
1721 Res::Def(kind, def_id) => {
1722 diagnostic_name = collector.cx.tcx.item_name(def_id).as_str();
1723 (Some(kind), &*diagnostic_name)
1725 Res::PrimTy(ty) => (None, ty.name_str()),
1726 _ => unreachable!("only ADTs and primitives are in scope at module level"),
1728 let path_description = if let Some(kind) = kind {
1730 Mod | ForeignMod => "inner item",
1731 Struct => "field or associated item",
1732 Enum | Union => "variant or associated item",
1749 let note = assoc_item_not_allowed(res);
1750 if let Some(span) = sp {
1751 diag.span_label(span, ¬e);
1757 Trait | TyAlias | ForeignTy | OpaqueTy | TraitAlias | TyParam
1758 | Static => "associated item",
1759 Impl | GlobalAsm => unreachable!("not a path"),
1765 "the {} `{}` has no {} named `{}`",
1768 disambiguator.map_or(path_description, |d| d.descr()),
1771 if let Some(span) = sp {
1772 diag.span_label(span, ¬e);
1779 let note = match failure {
1780 ResolutionFailure::NotResolved { .. } => unreachable!("handled above"),
1781 ResolutionFailure::Dummy => continue,
1782 ResolutionFailure::WrongNamespace(res, expected_ns) => {
1783 if let Res::Def(kind, _) = res {
1784 let disambiguator = Disambiguator::Kind(kind);
1785 suggest_disambiguator(
1796 "this link resolves to {}, which is not in the {} namespace",
1801 ResolutionFailure::NoParentItem => {
1802 diag.level = rustc_errors::Level::Bug;
1803 "all intra doc links should have a parent item".to_owned()
1805 ResolutionFailure::MalformedGenerics(variant) => match variant {
1806 MalformedGenerics::UnbalancedAngleBrackets => {
1807 String::from("unbalanced angle brackets")
1809 MalformedGenerics::MissingType => {
1810 String::from("missing type for generic parameters")
1812 MalformedGenerics::HasFullyQualifiedSyntax => {
1813 diag.note("see https://github.com/rust-lang/rust/issues/74563 for more information");
1814 String::from("fully-qualified syntax is unsupported")
1816 MalformedGenerics::InvalidPathSeparator => {
1817 String::from("has invalid path separator")
1819 MalformedGenerics::TooManyAngleBrackets => {
1820 String::from("too many angle brackets")
1822 MalformedGenerics::EmptyAngleBrackets => {
1823 String::from("empty angle brackets")
1827 if let Some(span) = sp {
1828 diag.span_label(span, ¬e);
1837 /// Report an anchor failure.
1839 cx: &DocContext<'_>,
1843 link_range: Option<Range<usize>>,
1844 failure: AnchorFailure,
1846 let msg = match failure {
1847 AnchorFailure::MultipleAnchors => format!("`{}` contains multiple anchors", path_str),
1848 AnchorFailure::RustdocAnchorConflict(res) => format!(
1849 "`{}` contains an anchor, but links to {kind}s are already anchored",
1855 report_diagnostic(cx, BROKEN_INTRA_DOC_LINKS, &msg, item, dox, &link_range, |diag, sp| {
1856 if let Some(sp) = sp {
1857 diag.span_label(sp, "contains invalid anchor");
1862 /// Report an ambiguity error, where there were multiple possible resolutions.
1864 cx: &DocContext<'_>,
1868 link_range: Option<Range<usize>>,
1869 candidates: Vec<Res>,
1871 let mut msg = format!("`{}` is ", path_str);
1873 match candidates.as_slice() {
1874 [first_def, second_def] => {
1876 "both {} {} and {} {}",
1877 first_def.article(),
1879 second_def.article(),
1884 let mut candidates = candidates.iter().peekable();
1885 while let Some(res) = candidates.next() {
1886 if candidates.peek().is_some() {
1887 msg += &format!("{} {}, ", res.article(), res.descr());
1889 msg += &format!("and {} {}", res.article(), res.descr());
1895 report_diagnostic(cx, BROKEN_INTRA_DOC_LINKS, &msg, item, dox, &link_range, |diag, sp| {
1896 if let Some(sp) = sp {
1897 diag.span_label(sp, "ambiguous link");
1899 diag.note("ambiguous link");
1902 for res in candidates {
1903 let disambiguator = Disambiguator::from_res(res);
1904 suggest_disambiguator(disambiguator, diag, path_str, dox, sp, &link_range);
1909 /// In case of an ambiguity or mismatched disambiguator, suggest the correct
1911 fn suggest_disambiguator(
1912 disambiguator: Disambiguator,
1913 diag: &mut DiagnosticBuilder<'_>,
1916 sp: Option<rustc_span::Span>,
1917 link_range: &Option<Range<usize>>,
1919 let suggestion = disambiguator.suggestion();
1920 let help = format!("to link to the {}, {}", disambiguator.descr(), suggestion.descr());
1922 if let Some(sp) = sp {
1923 let link_range = link_range.as_ref().expect("must have a link range if we have a span");
1924 let msg = if dox.bytes().nth(link_range.start) == Some(b'`') {
1925 format!("`{}`", suggestion.as_help(path_str))
1927 suggestion.as_help(path_str)
1930 diag.span_suggestion(sp, &help, msg, Applicability::MaybeIncorrect);
1932 diag.help(&format!("{}: {}", help, suggestion.as_help(path_str)));
1936 /// Report a link from a public item to a private one.
1938 cx: &DocContext<'_>,
1942 link_range: Option<Range<usize>>,
1944 let item_name = item.name.as_deref().unwrap_or("<unknown>");
1946 format!("public documentation for `{}` links to private item `{}`", item_name, path_str);
1948 report_diagnostic(cx, PRIVATE_INTRA_DOC_LINKS, &msg, item, dox, &link_range, |diag, sp| {
1949 if let Some(sp) = sp {
1950 diag.span_label(sp, "this item is private");
1953 let note_msg = if cx.render_options.document_private {
1954 "this link resolves only because you passed `--document-private-items`, but will break without"
1956 "this link will resolve properly if you pass `--document-private-items`"
1958 diag.note(note_msg);
1962 /// Given an enum variant's res, return the res of its enum and the associated fragment.
1964 cx: &DocContext<'_>,
1966 extra_fragment: &Option<String>,
1967 ) -> Result<(Res, Option<String>), ErrorKind<'static>> {
1968 use rustc_middle::ty::DefIdTree;
1970 if extra_fragment.is_some() {
1971 return Err(ErrorKind::AnchorFailure(AnchorFailure::RustdocAnchorConflict(res)));
1974 .parent(res.def_id())
1976 let parent_def = Res::Def(DefKind::Enum, parent);
1977 let variant = cx.tcx.expect_variant_res(res);
1978 (parent_def, Some(format!("variant.{}", variant.ident.name)))
1980 .ok_or_else(|| ResolutionFailure::NoParentItem.into())
1983 // FIXME: At this point, this is basically a copy of the PrimitiveTypeTable
1984 const PRIMITIVES: &[(Symbol, Res)] = &[
1985 (sym::u8, Res::PrimTy(hir::PrimTy::Uint(rustc_ast::UintTy::U8))),
1986 (sym::u16, Res::PrimTy(hir::PrimTy::Uint(rustc_ast::UintTy::U16))),
1987 (sym::u32, Res::PrimTy(hir::PrimTy::Uint(rustc_ast::UintTy::U32))),
1988 (sym::u64, Res::PrimTy(hir::PrimTy::Uint(rustc_ast::UintTy::U64))),
1989 (sym::u128, Res::PrimTy(hir::PrimTy::Uint(rustc_ast::UintTy::U128))),
1990 (sym::usize, Res::PrimTy(hir::PrimTy::Uint(rustc_ast::UintTy::Usize))),
1991 (sym::i8, Res::PrimTy(hir::PrimTy::Int(rustc_ast::IntTy::I8))),
1992 (sym::i16, Res::PrimTy(hir::PrimTy::Int(rustc_ast::IntTy::I16))),
1993 (sym::i32, Res::PrimTy(hir::PrimTy::Int(rustc_ast::IntTy::I32))),
1994 (sym::i64, Res::PrimTy(hir::PrimTy::Int(rustc_ast::IntTy::I64))),
1995 (sym::i128, Res::PrimTy(hir::PrimTy::Int(rustc_ast::IntTy::I128))),
1996 (sym::isize, Res::PrimTy(hir::PrimTy::Int(rustc_ast::IntTy::Isize))),
1997 (sym::f32, Res::PrimTy(hir::PrimTy::Float(rustc_ast::FloatTy::F32))),
1998 (sym::f64, Res::PrimTy(hir::PrimTy::Float(rustc_ast::FloatTy::F64))),
1999 (sym::str, Res::PrimTy(hir::PrimTy::Str)),
2000 (sym::bool, Res::PrimTy(hir::PrimTy::Bool)),
2001 (sym::char, Res::PrimTy(hir::PrimTy::Char)),
2004 /// Resolve a primitive type or value.
2005 fn resolve_primitive(path_str: &str, ns: Namespace) -> Option<(Symbol, Res)> {
2006 is_bool_value(path_str, ns).or_else(|| {
2008 // FIXME: this should be replaced by a lookup in PrimitiveTypeTable
2009 let maybe_primitive = Symbol::intern(path_str);
2010 PRIMITIVES.iter().find(|x| x.0 == maybe_primitive).copied()
2017 /// Resolve a primitive value.
2018 fn is_bool_value(path_str: &str, ns: Namespace) -> Option<(Symbol, Res)> {
2019 if ns == TypeNS && (path_str == "true" || path_str == "false") {
2020 Some((sym::bool, Res::PrimTy(hir::PrimTy::Bool)))
2026 fn strip_generics_from_path(path_str: &str) -> Result<String, ResolutionFailure<'static>> {
2027 let mut stripped_segments = vec![];
2028 let mut path = path_str.chars().peekable();
2029 let mut segment = Vec::new();
2031 while let Some(chr) = path.next() {
2034 if path.next_if_eq(&':').is_some() {
2035 let stripped_segment =
2036 strip_generics_from_path_segment(mem::take(&mut segment))?;
2037 if !stripped_segment.is_empty() {
2038 stripped_segments.push(stripped_segment);
2041 return Err(ResolutionFailure::MalformedGenerics(
2042 MalformedGenerics::InvalidPathSeparator,
2051 return Err(ResolutionFailure::MalformedGenerics(
2052 MalformedGenerics::TooManyAngleBrackets,
2056 return Err(ResolutionFailure::MalformedGenerics(
2057 MalformedGenerics::EmptyAngleBrackets,
2063 while let Some(chr) = path.next_if(|c| *c != '>') {
2070 _ => segment.push(chr),
2072 trace!("raw segment: {:?}", segment);
2075 if !segment.is_empty() {
2076 let stripped_segment = strip_generics_from_path_segment(segment)?;
2077 if !stripped_segment.is_empty() {
2078 stripped_segments.push(stripped_segment);
2082 debug!("path_str: {:?}\nstripped segments: {:?}", path_str, &stripped_segments);
2084 let stripped_path = stripped_segments.join("::");
2086 if !stripped_path.is_empty() {
2089 Err(ResolutionFailure::MalformedGenerics(MalformedGenerics::MissingType))
2093 fn strip_generics_from_path_segment(
2095 ) -> Result<String, ResolutionFailure<'static>> {
2096 let mut stripped_segment = String::new();
2097 let mut param_depth = 0;
2099 let mut latest_generics_chunk = String::new();
2104 latest_generics_chunk.clear();
2105 } else if c == '>' {
2107 if latest_generics_chunk.contains(" as ") {
2108 // The segment tries to use fully-qualified syntax, which is currently unsupported.
2109 // Give a helpful error message instead of completely ignoring the angle brackets.
2110 return Err(ResolutionFailure::MalformedGenerics(
2111 MalformedGenerics::HasFullyQualifiedSyntax,
2115 if param_depth == 0 {
2116 stripped_segment.push(c);
2118 latest_generics_chunk.push(c);
2123 if param_depth == 0 {
2124 Ok(stripped_segment)
2126 // The segment has unbalanced angle brackets, e.g. `Vec<T` or `Vec<T>>`
2127 Err(ResolutionFailure::MalformedGenerics(MalformedGenerics::UnbalancedAngleBrackets))