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
5 use pulldown_cmark::LinkType;
6 use rustc_ast::util::comments::may_have_doc_links;
7 use rustc_data_structures::{
8 fx::{FxHashMap, FxHashSet},
11 use rustc_errors::{Applicability, Diagnostic};
12 use rustc_hir::def::Namespace::*;
13 use rustc_hir::def::{DefKind, Namespace, PerNS};
14 use rustc_hir::def_id::{DefId, CRATE_DEF_ID};
15 use rustc_hir::Mutability;
16 use rustc_middle::ty::{DefIdTree, Ty, TyCtxt};
17 use rustc_middle::{bug, ty};
18 use rustc_resolve::ParentScope;
19 use rustc_session::lint::Lint;
20 use rustc_span::hygiene::MacroKind;
21 use rustc_span::symbol::{sym, Ident, Symbol};
22 use rustc_span::BytePos;
23 use smallvec::{smallvec, SmallVec};
29 use crate::clean::{self, utils::find_nearest_parent_module};
30 use crate::clean::{Crate, Item, ItemId, ItemLink, PrimitiveType};
31 use crate::core::DocContext;
32 use crate::html::markdown::{markdown_links, MarkdownLink};
33 use crate::lint::{BROKEN_INTRA_DOC_LINKS, PRIVATE_INTRA_DOC_LINKS};
34 use crate::passes::Pass;
35 use crate::visit::DocVisitor;
38 pub(crate) use early::early_resolve_intra_doc_links;
40 pub(crate) const COLLECT_INTRA_DOC_LINKS: Pass = Pass {
41 name: "collect-intra-doc-links",
42 run: collect_intra_doc_links,
43 description: "resolves intra-doc links",
46 fn collect_intra_doc_links(krate: Crate, cx: &mut DocContext<'_>) -> Crate {
48 LinkCollector { cx, mod_ids: Vec::new(), visited_links: FxHashMap::default() };
49 collector.visit_crate(&krate);
53 #[derive(Copy, Clone, Debug, Hash)]
56 Primitive(PrimitiveType),
59 type ResolveRes = rustc_hir::def::Res<rustc_ast::NodeId>;
62 fn descr(self) -> &'static str {
64 Res::Def(kind, id) => ResolveRes::Def(kind, id).descr(),
65 Res::Primitive(_) => "builtin type",
69 fn article(self) -> &'static str {
71 Res::Def(kind, id) => ResolveRes::Def(kind, id).article(),
72 Res::Primitive(_) => "a",
76 fn name(self, tcx: TyCtxt<'_>) -> Symbol {
78 Res::Def(_, id) => tcx.item_name(id),
79 Res::Primitive(prim) => prim.as_sym(),
83 fn def_id(self, tcx: TyCtxt<'_>) -> DefId {
85 Res::Def(_, id) => id,
86 Res::Primitive(prim) => *PrimitiveType::primitive_locations(tcx).get(&prim).unwrap(),
90 fn from_def_id(tcx: TyCtxt<'_>, def_id: DefId) -> Res {
91 Res::Def(tcx.def_kind(def_id), def_id)
94 /// Used for error reporting.
95 fn disambiguator_suggestion(self) -> Suggestion {
96 let kind = match self {
97 Res::Primitive(_) => return Suggestion::Prefix("prim"),
98 Res::Def(kind, _) => kind,
100 if kind == DefKind::Macro(MacroKind::Bang) {
101 return Suggestion::Macro;
102 } else if kind == DefKind::Fn || kind == DefKind::AssocFn {
103 return Suggestion::Function;
104 } else if kind == DefKind::Field {
105 return Suggestion::RemoveDisambiguator;
108 let prefix = match kind {
109 DefKind::Struct => "struct",
110 DefKind::Enum => "enum",
111 DefKind::Trait => "trait",
112 DefKind::Union => "union",
113 DefKind::Mod => "mod",
114 DefKind::Const | DefKind::ConstParam | DefKind::AssocConst | DefKind::AnonConst => {
117 DefKind::Static(_) => "static",
118 DefKind::Macro(MacroKind::Derive) => "derive",
119 // Now handle things that don't have a specific disambiguator
122 .expect("tried to calculate a disambiguator for a def without a namespace?")
124 Namespace::TypeNS => "type",
125 Namespace::ValueNS => "value",
126 Namespace::MacroNS => "macro",
130 Suggestion::Prefix(prefix)
134 impl TryFrom<ResolveRes> for Res {
137 fn try_from(res: ResolveRes) -> Result<Self, ()> {
138 use rustc_hir::def::Res::*;
140 Def(kind, id) => Ok(Res::Def(kind, id)),
141 PrimTy(prim) => Ok(Res::Primitive(PrimitiveType::from_hir(prim))),
143 NonMacroAttr(..) | Err => Result::Err(()),
144 other => bug!("unrecognized res {:?}", other),
149 /// The link failed to resolve. [`resolution_failure`] should look to see if there's
150 /// a more helpful error that can be given.
152 struct UnresolvedPath<'a> {
153 /// Item on which the link is resolved, used for resolving `Self`.
155 /// The scope the link was resolved in.
157 /// If part of the link resolved, this has the `Res`.
159 /// In `[std::io::Error::x]`, `std::io::Error` would be a partial resolution.
160 partial_res: Option<Res>,
161 /// The remaining unresolved path segments.
163 /// In `[std::io::Error::x]`, `x` would be unresolved.
164 unresolved: Cow<'a, str>,
168 enum ResolutionFailure<'a> {
169 /// This resolved, but with the wrong namespace.
171 /// What the link resolved to.
173 /// The expected namespace for the resolution, determined from the link's disambiguator.
175 /// E.g., for `[fn@Result]` this is [`Namespace::ValueNS`],
176 /// even though `Result`'s actual namespace is [`Namespace::TypeNS`].
177 expected_ns: Namespace,
179 NotResolved(UnresolvedPath<'a>),
182 #[derive(Clone, Copy, Debug)]
183 enum MalformedGenerics {
184 /// This link has unbalanced angle brackets.
186 /// For example, `Vec<T` should trigger this, as should `Vec<T>>`.
187 UnbalancedAngleBrackets,
188 /// The generics are not attached to a type.
190 /// For example, `<T>` should trigger this.
192 /// This is detected by checking if the path is empty after the generics are stripped.
194 /// The link uses fully-qualified syntax, which is currently unsupported.
196 /// For example, `<Vec as IntoIterator>::into_iter` should trigger this.
198 /// This is detected by checking if ` as ` (the keyword `as` with spaces around it) is inside
200 HasFullyQualifiedSyntax,
201 /// The link has an invalid path separator.
203 /// For example, `Vec:<T>:new()` should trigger this. Note that `Vec:new()` will **not**
204 /// trigger this because it has no generics and thus [`strip_generics_from_path`] will not be
207 /// Note that this will also **not** be triggered if the invalid path separator is inside angle
208 /// brackets because rustdoc mostly ignores what's inside angle brackets (except for
209 /// [`HasFullyQualifiedSyntax`](MalformedGenerics::HasFullyQualifiedSyntax)).
211 /// This is detected by checking if there is a colon followed by a non-colon in the link.
212 InvalidPathSeparator,
213 /// The link has too many angle brackets.
215 /// For example, `Vec<<T>>` should trigger this.
216 TooManyAngleBrackets,
217 /// The link has empty angle brackets.
219 /// For example, `Vec<>` should trigger this.
223 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
224 pub(crate) enum UrlFragment {
230 /// Render the fragment, including the leading `#`.
231 pub(crate) fn render(&self, s: &mut String, tcx: TyCtxt<'_>) {
234 &UrlFragment::Item(def_id) => {
235 let kind = match tcx.def_kind(def_id) {
236 DefKind::AssocFn => {
237 if tcx.impl_defaultness(def_id).has_value() {
243 DefKind::AssocConst => "associatedconstant.",
244 DefKind::AssocTy => "associatedtype.",
245 DefKind::Variant => "variant.",
247 let parent_id = tcx.parent(def_id);
248 if tcx.def_kind(parent_id) == DefKind::Variant {
249 s.push_str("variant.");
250 s.push_str(tcx.item_name(parent_id).as_str());
256 kind => bug!("unexpected associated item kind: {:?}", kind),
259 s.push_str(tcx.item_name(def_id).as_str());
261 UrlFragment::UserWritten(raw) => s.push_str(&raw),
266 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
267 struct ResolutionInfo {
270 dis: Option<Disambiguator>,
272 extra_fragment: Option<String>,
276 struct DiagnosticInfo<'a> {
280 link_range: Range<usize>,
283 struct LinkCollector<'a, 'tcx> {
284 cx: &'a mut DocContext<'tcx>,
285 /// A stack of modules used to decide what scope to resolve in.
287 /// The last module will be used if the parent scope of the current item is
290 /// Cache the resolved links so we can avoid resolving (and emitting errors for) the same link.
291 /// The link will be `None` if it could not be resolved (i.e. the error was cached).
292 visited_links: FxHashMap<ResolutionInfo, Option<(Res, Option<UrlFragment>)>>,
295 impl<'a, 'tcx> LinkCollector<'a, 'tcx> {
296 /// Given a full link, parse it as an [enum struct variant].
298 /// In particular, this will return an error whenever there aren't three
299 /// full path segments left in the link.
301 /// [enum struct variant]: rustc_hir::VariantData::Struct
302 fn variant_field<'path>(
304 path_str: &'path str,
307 ) -> Result<(Res, DefId), UnresolvedPath<'path>> {
308 let tcx = self.cx.tcx;
309 let no_res = || UnresolvedPath {
313 unresolved: path_str.into(),
316 debug!("looking for enum variant {}", path_str);
317 let mut split = path_str.rsplitn(3, "::");
318 let variant_field_name = split
320 .map(|f| Symbol::intern(f))
321 .expect("fold_item should ensure link is non-empty");
323 // we're not sure this is a variant at all, so use the full string
324 // If there's no second component, the link looks like `[path]`.
325 // So there's no partial res and we should say the whole link failed to resolve.
326 split.next().map(|f| Symbol::intern(f)).ok_or_else(no_res)?;
329 .map(|f| f.to_owned())
330 // If there's no third component, we saw `[a::b]` before and it failed to resolve.
331 // So there's no partial res.
332 .ok_or_else(no_res)?;
333 let ty_res = self.resolve_path(&path, TypeNS, item_id, module_id).ok_or_else(no_res)?;
336 Res::Def(DefKind::Enum, did) => match tcx.type_of(did).kind() {
337 ty::Adt(def, _) if def.is_enum() => {
338 if let Some(field) = def.all_fields().find(|f| f.name == variant_field_name) {
339 Ok((ty_res, field.did))
344 partial_res: Some(Res::Def(DefKind::Enum, def.did())),
345 unresolved: variant_field_name.to_string().into(),
351 _ => Err(UnresolvedPath {
354 partial_res: Some(ty_res),
355 unresolved: variant_name.to_string().into(),
360 /// Given a primitive type, try to resolve an associated item.
361 fn resolve_primitive_associated_item(
363 prim_ty: PrimitiveType,
366 ) -> Option<(Res, DefId)> {
367 let tcx = self.cx.tcx;
369 prim_ty.impls(tcx).find_map(|impl_| {
370 tcx.associated_items(impl_)
371 .find_by_name_and_namespace(tcx, Ident::with_dummy_span(item_name), ns, impl_)
372 .map(|item| (Res::Primitive(prim_ty), item.def_id))
376 fn resolve_self_ty(&self, path_str: &str, ns: Namespace, item_id: ItemId) -> Option<Res> {
377 if ns != TypeNS || path_str != "Self" {
381 let tcx = self.cx.tcx;
384 .map(|def_id| match tcx.def_kind(def_id) {
385 def_kind @ (DefKind::AssocFn
386 | DefKind::AssocConst
389 | DefKind::Field) => {
390 let parent_def_id = tcx.parent(def_id);
391 if def_kind == DefKind::Field && tcx.def_kind(parent_def_id) == DefKind::Variant
393 tcx.parent(parent_def_id)
400 .and_then(|self_id| match tcx.def_kind(self_id) {
401 DefKind::Impl => self.def_id_to_res(self_id),
402 def_kind => Some(Res::Def(def_kind, self_id)),
406 /// Convenience wrapper around `resolve_rustdoc_path`.
408 /// This also handles resolving `true` and `false` as booleans.
409 /// NOTE: `resolve_rustdoc_path` knows only about paths, not about types.
410 /// Associated items will never be resolved by this function.
418 if let res @ Some(..) = self.resolve_self_ty(path_str, ns, item_id) {
422 // Resolver doesn't know about true, false, and types that aren't paths (e.g. `()`).
426 .doc_link_resolutions
427 .get(&(Symbol::intern(path_str), ns, module_id))
430 self.cx.enter_resolver(|resolver| {
432 ParentScope::module(resolver.expect_module(module_id), resolver);
433 resolver.resolve_rustdoc_path(path_str, ns, parent_scope)
436 .and_then(|res| res.try_into().ok())
437 .or_else(|| resolve_primitive(path_str, ns));
438 debug!("{} resolved to {:?} in namespace {:?}", path_str, result, ns);
442 /// Resolves a string as a path within a particular namespace. Returns an
443 /// optional URL fragment in the case of variants and methods.
446 path_str: &'path str,
450 ) -> Result<(Res, Option<DefId>), UnresolvedPath<'path>> {
451 if let Some(res) = self.resolve_path(path_str, ns, item_id, module_id) {
452 return Ok(match res {
454 DefKind::AssocFn | DefKind::AssocConst | DefKind::AssocTy | DefKind::Variant,
456 ) => (Res::from_def_id(self.cx.tcx, self.cx.tcx.parent(def_id)), Some(def_id)),
459 } else if ns == MacroNS {
460 return Err(UnresolvedPath {
464 unresolved: path_str.into(),
468 // Try looking for methods and associated items.
469 let mut split = path_str.rsplitn(2, "::");
470 // NB: `split`'s first element is always defined, even if the delimiter was not present.
471 // NB: `item_str` could be empty when resolving in the root namespace (e.g. `::std`).
472 let item_str = split.next().unwrap();
473 let item_name = Symbol::intern(item_str);
474 let path_root = split
476 .map(|f| f.to_owned())
477 // If there's no `::`, it's not an associated item.
478 // So we can be sure that `rustc_resolve` was accurate when it said it wasn't resolved.
480 debug!("found no `::`, assumming {} was correctly not in scope", item_name);
485 unresolved: item_str.into(),
489 // FIXME(#83862): this arbitrarily gives precedence to primitives over modules to support
490 // links to primitives when `#[doc(primitive)]` is present. It should give an ambiguity
491 // error instead and special case *only* modules with `#[doc(primitive)]`, not all
493 resolve_primitive(&path_root, TypeNS)
494 .or_else(|| self.resolve_path(&path_root, TypeNS, item_id, module_id))
496 self.resolve_associated_item(ty_res, item_name, ns, module_id).map(Ok)
499 if ns == Namespace::ValueNS {
500 self.variant_field(path_str, item_id, module_id)
506 unresolved: path_root.into(),
510 .map(|(res, def_id)| (res, Some(def_id)))
513 /// Convert a DefId to a Res, where possible.
515 /// This is used for resolving type aliases.
516 fn def_id_to_res(&self, ty_id: DefId) -> Option<Res> {
517 use PrimitiveType::*;
518 Some(match *self.cx.tcx.type_of(ty_id).kind() {
519 ty::Bool => Res::Primitive(Bool),
520 ty::Char => Res::Primitive(Char),
521 ty::Int(ity) => Res::Primitive(ity.into()),
522 ty::Uint(uty) => Res::Primitive(uty.into()),
523 ty::Float(fty) => Res::Primitive(fty.into()),
524 ty::Str => Res::Primitive(Str),
525 ty::Tuple(tys) if tys.is_empty() => Res::Primitive(Unit),
526 ty::Tuple(_) => Res::Primitive(Tuple),
527 ty::Array(..) => Res::Primitive(Array),
528 ty::Slice(_) => Res::Primitive(Slice),
529 ty::RawPtr(_) => Res::Primitive(RawPointer),
530 ty::Ref(..) => Res::Primitive(Reference),
531 ty::FnDef(..) => panic!("type alias to a function definition"),
532 ty::FnPtr(_) => Res::Primitive(Fn),
533 ty::Never => Res::Primitive(Never),
534 ty::Adt(ty::AdtDef(Interned(&ty::AdtDefData { did, .. }, _)), _) | ty::Foreign(did) => {
535 Res::from_def_id(self.cx.tcx, did)
540 | ty::GeneratorWitness(_)
547 | ty::Error(_) => return None,
551 /// Convert a PrimitiveType to a Ty, where possible.
553 /// This is used for resolving trait impls for primitives
554 fn primitive_type_to_ty(&mut self, prim: PrimitiveType) -> Option<Ty<'tcx>> {
555 use PrimitiveType::*;
556 let tcx = self.cx.tcx;
558 // FIXME: Only simple types are supported here, see if we can support
559 // other types such as Tuple, Array, Slice, etc.
560 // See https://github.com/rust-lang/rust/issues/90703#issuecomment-1004263455
561 Some(tcx.mk_ty(match prim {
566 I8 => ty::Int(ty::IntTy::I8),
567 I16 => ty::Int(ty::IntTy::I16),
568 I32 => ty::Int(ty::IntTy::I32),
569 I64 => ty::Int(ty::IntTy::I64),
570 I128 => ty::Int(ty::IntTy::I128),
571 Isize => ty::Int(ty::IntTy::Isize),
572 F32 => ty::Float(ty::FloatTy::F32),
573 F64 => ty::Float(ty::FloatTy::F64),
574 U8 => ty::Uint(ty::UintTy::U8),
575 U16 => ty::Uint(ty::UintTy::U16),
576 U32 => ty::Uint(ty::UintTy::U32),
577 U64 => ty::Uint(ty::UintTy::U64),
578 U128 => ty::Uint(ty::UintTy::U128),
579 Usize => ty::Uint(ty::UintTy::Usize),
584 /// Resolve an associated item, returning its containing page's `Res`
585 /// and the fragment targeting the associated item on its page.
586 fn resolve_associated_item(
592 ) -> Option<(Res, DefId)> {
593 let tcx = self.cx.tcx;
596 Res::Primitive(prim) => {
597 self.resolve_primitive_associated_item(prim, ns, item_name).or_else(|| {
598 self.primitive_type_to_ty(prim)
600 resolve_associated_trait_item(ty, module_id, item_name, ns, self.cx)
602 .map(|item| (root_res, item.def_id))
605 Res::Def(DefKind::TyAlias, did) => {
606 // Resolve the link on the type the alias points to.
607 // FIXME: if the associated item is defined directly on the type alias,
608 // it will show up on its documentation page, we should link there instead.
609 let res = self.def_id_to_res(did)?;
610 self.resolve_associated_item(res, item_name, ns, module_id)
613 def_kind @ (DefKind::Struct | DefKind::Union | DefKind::Enum | DefKind::ForeignTy),
616 debug!("looking for associated item named {} for item {:?}", item_name, did);
617 // Checks if item_name is a variant of the `SomeItem` enum
618 if ns == TypeNS && def_kind == DefKind::Enum {
619 match tcx.type_of(did).kind() {
620 ty::Adt(adt_def, _) => {
621 for variant in adt_def.variants() {
622 if variant.name == item_name {
623 return Some((root_res, variant.def_id));
631 // Checks if item_name belongs to `impl SomeItem`
636 tcx.associated_items(imp).find_by_name_and_namespace(
638 Ident::with_dummy_span(item_name),
644 // There should only ever be one associated item that matches from any inherent impl
646 // Check if item_name belongs to `impl SomeTrait for SomeItem`
647 // FIXME(#74563): This gives precedence to `impl SomeItem`:
648 // Although having both would be ambiguous, use impl version for compatibility's sake.
649 // To handle that properly resolve() would have to support
650 // something like [`ambi_fn`](<SomeStruct as SomeTrait>::ambi_fn)
652 resolve_associated_trait_item(
661 debug!("got associated item {:?}", assoc_item);
663 if let Some(item) = assoc_item {
664 return Some((root_res, item.def_id));
667 if ns != Namespace::ValueNS {
670 debug!("looking for fields named {} for {:?}", item_name, did);
671 // FIXME: this doesn't really belong in `associated_item` (maybe `variant_field` is better?)
672 // NOTE: it's different from variant_field because it only resolves struct fields,
673 // not variant fields (2 path segments, not 3).
675 // We need to handle struct (and union) fields in this code because
676 // syntactically their paths are identical to associated item paths:
677 // `module::Type::field` and `module::Type::Assoc`.
679 // On the other hand, variant fields can't be mistaken for associated
680 // items because they look like this: `module::Type::Variant::field`.
682 // Variants themselves don't need to be handled here, even though
683 // they also look like associated items (`module::Type::Variant`),
684 // because they are real Rust syntax (unlike the intra-doc links
685 // field syntax) and are handled by the compiler's resolver.
686 let def = match tcx.type_of(did).kind() {
687 ty::Adt(def, _) if !def.is_enum() => def,
691 def.non_enum_variant().fields.iter().find(|item| item.name == item_name)?;
692 Some((root_res, field.did))
694 Res::Def(DefKind::Trait, did) => tcx
695 .associated_items(did)
696 .find_by_name_and_namespace(tcx, Ident::with_dummy_span(item_name), ns, did)
698 let res = Res::Def(item.kind.as_def_kind(), item.def_id);
706 fn full_res(tcx: TyCtxt<'_>, (base, assoc_item): (Res, Option<DefId>)) -> Res {
707 assoc_item.map_or(base, |def_id| Res::from_def_id(tcx, def_id))
710 /// Look to see if a resolved item has an associated item named `item_name`.
712 /// Given `[std::io::Error::source]`, where `source` is unresolved, this would
713 /// find `std::error::Error::source` and return
714 /// `<io::Error as error::Error>::source`.
715 fn resolve_associated_trait_item<'a>(
720 cx: &mut DocContext<'a>,
721 ) -> Option<ty::AssocItem> {
722 // FIXME: this should also consider blanket impls (`impl<T> X for T`). Unfortunately
723 // `get_auto_trait_and_blanket_impls` is broken because the caching behavior is wrong. In the
724 // meantime, just don't look for these blanket impls.
726 // Next consider explicit impls: `impl MyTrait for MyType`
727 // Give precedence to inherent impls.
728 let traits = trait_impls_for(cx, ty, module);
729 debug!("considering traits {:?}", traits);
730 let mut candidates = traits.iter().filter_map(|&(impl_, trait_)| {
732 .associated_items(trait_)
733 .find_by_name_and_namespace(cx.tcx, Ident::with_dummy_span(item_name), ns, trait_)
735 trait_assoc_to_impl_assoc_item(cx.tcx, impl_, trait_assoc.def_id)
736 .unwrap_or(trait_assoc)
739 // FIXME(#74563): warn about ambiguity
740 debug!("the candidates were {:?}", candidates.clone().collect::<Vec<_>>());
741 candidates.next().copied()
744 /// Find the associated item in the impl `impl_id` that corresponds to the
745 /// trait associated item `trait_assoc_id`.
747 /// This function returns `None` if no associated item was found in the impl.
748 /// This can occur when the trait associated item has a default value that is
749 /// not overridden in the impl.
751 /// This is just a wrapper around [`TyCtxt::impl_item_implementor_ids()`] and
752 /// [`TyCtxt::associated_item()`] (with some helpful logging added).
753 #[instrument(level = "debug", skip(tcx))]
754 fn trait_assoc_to_impl_assoc_item<'tcx>(
757 trait_assoc_id: DefId,
758 ) -> Option<&'tcx ty::AssocItem> {
759 let trait_to_impl_assoc_map = tcx.impl_item_implementor_ids(impl_id);
760 debug!(?trait_to_impl_assoc_map);
761 let impl_assoc_id = *trait_to_impl_assoc_map.get(&trait_assoc_id)?;
762 debug!(?impl_assoc_id);
763 let impl_assoc = tcx.associated_item(impl_assoc_id);
768 /// Given a type, return all trait impls in scope in `module` for that type.
769 /// Returns a set of pairs of `(impl_id, trait_id)`.
771 /// NOTE: this cannot be a query because more traits could be available when more crates are compiled!
772 /// So it is not stable to serialize cross-crate.
773 #[instrument(level = "debug", skip(cx))]
774 fn trait_impls_for<'a>(
775 cx: &mut DocContext<'a>,
778 ) -> FxHashSet<(DefId, DefId)> {
780 let iter = cx.resolver_caches.traits_in_scope[&module].iter().flat_map(|trait_candidate| {
781 let trait_ = trait_candidate.def_id;
782 trace!("considering explicit impl for trait {:?}", trait_);
784 // Look at each trait implementation to see if it's an impl for `did`
785 tcx.find_map_relevant_impl(trait_, ty, |impl_| {
786 let trait_ref = tcx.impl_trait_ref(impl_).expect("this is not an inherent impl");
787 // Check if these are the same type.
788 let impl_type = trait_ref.self_ty();
790 "comparing type {} with kind {:?} against type {:?}",
795 // Fast path: if this is a primitive simple `==` will work
796 // NOTE: the `match` is necessary; see #92662.
797 // this allows us to ignore generics because the user input
798 // may not include the generic placeholders
799 // e.g. this allows us to match Foo (user comment) with Foo<T> (actual type)
800 let saw_impl = impl_type == ty
801 || match (impl_type.kind(), ty.kind()) {
802 (ty::Adt(impl_def, _), ty::Adt(ty_def, _)) => {
803 debug!("impl def_id: {:?}, ty def_id: {:?}", impl_def.did(), ty_def.did());
804 impl_def.did() == ty_def.did()
809 if saw_impl { Some((impl_, trait_)) } else { None }
815 /// Check for resolve collisions between a trait and its derive.
817 /// These are common and we should just resolve to the trait in that case.
818 fn is_derive_trait_collision<T>(ns: &PerNS<Result<(Res, T), ResolutionFailure<'_>>>) -> bool {
822 type_ns: Ok((Res::Def(DefKind::Trait, _), _)),
823 macro_ns: Ok((Res::Def(DefKind::Macro(MacroKind::Derive), _), _)),
829 impl<'a, 'tcx> DocVisitor for LinkCollector<'a, 'tcx> {
830 fn visit_item(&mut self, item: &Item) {
832 item.item_id.as_def_id().and_then(|did| find_nearest_parent_module(self.cx.tcx, did));
833 if parent_node.is_some() {
834 trace!("got parent node for {:?} {:?}, id {:?}", item.type_(), item.name, item.item_id);
837 let inner_docs = item.inner_docs(self.cx.tcx);
839 if item.is_mod() && inner_docs {
840 self.mod_ids.push(item.item_id.expect_def_id());
843 // We want to resolve in the lexical scope of the documentation.
844 // In the presence of re-exports, this is not the same as the module of the item.
845 // Rather than merging all documentation into one, resolve it one attribute at a time
846 // so we know which module it came from.
847 for (parent_module, doc) in item.attrs.prepare_to_doc_link_resolution() {
848 if !may_have_doc_links(&doc) {
851 debug!("combined_docs={}", doc);
852 // NOTE: if there are links that start in one crate and end in another, this will not resolve them.
853 // This is a degenerate case and it's not supported by rustdoc.
854 let parent_node = parent_module.or(parent_node);
855 let mut tmp_links = self
860 .expect("`markdown_links` are already borrowed");
861 if !tmp_links.contains_key(&doc) {
862 tmp_links.insert(doc.clone(), preprocessed_markdown_links(&doc));
864 for md_link in &tmp_links[&doc] {
865 let link = self.resolve_link(item, &doc, parent_node, md_link);
866 if let Some(link) = link {
867 self.cx.cache.intra_doc_links.entry(item.item_id).or_default().push(link);
870 self.cx.resolver_caches.markdown_links = Some(tmp_links);
875 self.mod_ids.push(item.item_id.expect_def_id());
878 self.visit_item_recur(item);
881 self.visit_item_recur(item)
886 enum PreprocessingError {
887 /// User error: `[std#x#y]` is not valid
889 Disambiguator(Range<usize>, String),
890 MalformedGenerics(MalformedGenerics, String),
893 impl PreprocessingError {
894 fn report(&self, cx: &DocContext<'_>, diag_info: DiagnosticInfo<'_>) {
896 PreprocessingError::MultipleAnchors => report_multiple_anchors(cx, diag_info),
897 PreprocessingError::Disambiguator(range, msg) => {
898 disambiguator_error(cx, diag_info, range.clone(), msg)
900 PreprocessingError::MalformedGenerics(err, path_str) => {
901 report_malformed_generics(cx, diag_info, *err, path_str)
908 struct PreprocessingInfo {
910 disambiguator: Option<Disambiguator>,
911 extra_fragment: Option<String>,
915 // Not a typedef to avoid leaking several private structures from this module.
916 pub(crate) struct PreprocessedMarkdownLink(
917 Result<PreprocessingInfo, PreprocessingError>,
922 /// - `None` if the link should be ignored.
923 /// - `Some(Err)` if the link should emit an error
924 /// - `Some(Ok)` if the link is valid
926 /// `link_buffer` is needed for lifetime reasons; it will always be overwritten and the contents ignored.
928 ori_link: &MarkdownLink,
929 ) -> Option<Result<PreprocessingInfo, PreprocessingError>> {
930 // [] is mostly likely not supposed to be a link
931 if ori_link.link.is_empty() {
935 // Bail early for real links.
936 if ori_link.link.contains('/') {
940 let stripped = ori_link.link.replace('`', "");
941 let mut parts = stripped.split('#');
943 let link = parts.next().unwrap();
944 if link.trim().is_empty() {
945 // This is an anchor to an element of the current page, nothing to do in here!
948 let extra_fragment = parts.next();
949 if parts.next().is_some() {
950 // A valid link can't have multiple #'s
951 return Some(Err(PreprocessingError::MultipleAnchors));
954 // Parse and strip the disambiguator from the link, if present.
955 let (disambiguator, path_str, link_text) = match Disambiguator::from_str(link) {
956 Ok(Some((d, path, link_text))) => (Some(d), path.trim(), link_text.trim()),
957 Ok(None) => (None, link.trim(), link.trim()),
958 Err((err_msg, relative_range)) => {
959 // Only report error if we would not have ignored this link. See issue #83859.
960 if !should_ignore_link_with_disambiguators(link) {
961 let no_backticks_range = range_between_backticks(ori_link);
962 let disambiguator_range = (no_backticks_range.start + relative_range.start)
963 ..(no_backticks_range.start + relative_range.end);
964 return Some(Err(PreprocessingError::Disambiguator(disambiguator_range, err_msg)));
971 if should_ignore_link(path_str) {
975 // Strip generics from the path.
976 let path_str = if path_str.contains(['<', '>'].as_slice()) {
977 match strip_generics_from_path(path_str) {
980 debug!("link has malformed generics: {}", path_str);
981 return Some(Err(PreprocessingError::MalformedGenerics(err, path_str.to_owned())));
988 // Sanity check to make sure we don't have any angle brackets after stripping generics.
989 assert!(!path_str.contains(['<', '>'].as_slice()));
991 // The link is not an intra-doc link if it still contains spaces after stripping generics.
992 if path_str.contains(' ') {
996 Some(Ok(PreprocessingInfo {
999 extra_fragment: extra_fragment.map(|frag| frag.to_owned()),
1000 link_text: link_text.to_owned(),
1004 fn preprocessed_markdown_links(s: &str) -> Vec<PreprocessedMarkdownLink> {
1005 markdown_links(s, |link| {
1006 preprocess_link(&link).map(|pp_link| PreprocessedMarkdownLink(pp_link, link))
1010 impl LinkCollector<'_, '_> {
1011 /// This is the entry point for resolving an intra-doc link.
1013 /// FIXME(jynelson): this is way too many arguments
1018 parent_node: Option<DefId>,
1019 link: &PreprocessedMarkdownLink,
1020 ) -> Option<ItemLink> {
1021 let PreprocessedMarkdownLink(pp_link, ori_link) = link;
1022 trace!("considering link '{}'", ori_link.link);
1024 let diag_info = DiagnosticInfo {
1027 ori_link: &ori_link.link,
1028 link_range: ori_link.range.clone(),
1031 let PreprocessingInfo { path_str, disambiguator, extra_fragment, link_text } =
1032 pp_link.as_ref().map_err(|err| err.report(self.cx, diag_info.clone())).ok()?;
1033 let disambiguator = *disambiguator;
1035 // In order to correctly resolve intra-doc links we need to
1036 // pick a base AST node to work from. If the documentation for
1037 // this module came from an inner comment (//!) then we anchor
1038 // our name resolution *inside* the module. If, on the other
1039 // hand it was an outer comment (///) then we anchor the name
1040 // resolution in the parent module on the basis that the names
1041 // used are more likely to be intended to be parent names. For
1042 // this, we set base_node to None for inner comments since
1043 // we've already pushed this node onto the resolution stack but
1044 // for outer comments we explicitly try and resolve against the
1045 // parent_node first.
1046 let inner_docs = item.inner_docs(self.cx.tcx);
1048 if item.is_mod() && inner_docs { self.mod_ids.last().copied() } else { parent_node };
1049 let module_id = base_node.expect("doc link without parent module");
1051 let (mut res, fragment) = self.resolve_with_disambiguator_cached(
1053 item_id: item.item_id,
1056 path_str: path_str.to_owned(),
1057 extra_fragment: extra_fragment.clone(),
1059 diag_info.clone(), // this struct should really be Copy, but Range is not :(
1060 // For reference-style links we want to report only one error so unsuccessful
1061 // resolutions are cached, for other links we want to report an error every
1062 // time so they are not cached.
1063 matches!(ori_link.kind, LinkType::Reference | LinkType::Shortcut),
1066 // Check for a primitive which might conflict with a module
1067 // Report the ambiguity and require that the user specify which one they meant.
1068 // FIXME: could there ever be a primitive not in the type namespace?
1071 None | Some(Disambiguator::Namespace(Namespace::TypeNS) | Disambiguator::Primitive)
1072 ) && !matches!(res, Res::Primitive(_))
1074 if let Some(prim) = resolve_primitive(path_str, TypeNS) {
1076 if matches!(disambiguator, Some(Disambiguator::Primitive)) {
1079 // `[char]` when a `char` module is in scope
1080 let candidates = vec![res, prim];
1081 ambiguity_error(self.cx, diag_info, path_str, candidates);
1088 Res::Primitive(prim) => {
1089 if let Some(UrlFragment::Item(id)) = fragment {
1090 // We're actually resolving an associated item of a primitive, so we need to
1091 // verify the disambiguator (if any) matches the type of the associated item.
1092 // This case should really follow the same flow as the `Res::Def` branch below,
1093 // but attempting to add a call to `clean::register_res` causes an ICE. @jyn514
1094 // thinks `register_res` is only needed for cross-crate re-exports, but Rust
1095 // doesn't allow statements like `use str::trim;`, making this a (hopefully)
1096 // valid omission. See https://github.com/rust-lang/rust/pull/80660#discussion_r551585677
1097 // for discussion on the matter.
1098 let kind = self.cx.tcx.def_kind(id);
1099 self.verify_disambiguator(
1109 // FIXME: it would be nice to check that the feature gate was enabled in the original crate, not just ignore it altogether.
1110 // However I'm not sure how to check that across crates.
1111 if prim == PrimitiveType::RawPointer
1112 && item.item_id.is_local()
1113 && !self.cx.tcx.features().intra_doc_pointers
1115 self.report_rawptr_assoc_feature_gate(dox, ori_link, item);
1118 match disambiguator {
1119 Some(Disambiguator::Primitive | Disambiguator::Namespace(_)) | None => {}
1121 self.report_disambiguator_mismatch(
1122 path_str, ori_link, other, res, &diag_info,
1130 link: ori_link.link.clone(),
1131 link_text: link_text.clone(),
1132 did: res.def_id(self.cx.tcx),
1136 Res::Def(kind, id) => {
1137 let (kind_for_dis, id_for_dis) = if let Some(UrlFragment::Item(id)) = fragment {
1138 (self.cx.tcx.def_kind(id), id)
1142 self.verify_disambiguator(
1151 let id = clean::register_res(self.cx, rustc_hir::def::Res::Def(kind, id));
1153 link: ori_link.link.clone(),
1154 link_text: link_text.clone(),
1162 fn verify_disambiguator(
1165 ori_link: &MarkdownLink,
1168 disambiguator: Option<Disambiguator>,
1170 diag_info: &DiagnosticInfo<'_>,
1172 debug!("intra-doc link to {} resolved to {:?}", path_str, (kind, id));
1174 // Disallow e.g. linking to enums with `struct@`
1175 debug!("saw kind {:?} with disambiguator {:?}", kind, disambiguator);
1176 match (kind, disambiguator) {
1177 | (DefKind::Const | DefKind::ConstParam | DefKind::AssocConst | DefKind::AnonConst, Some(Disambiguator::Kind(DefKind::Const)))
1178 // NOTE: this allows 'method' to mean both normal functions and associated functions
1179 // This can't cause ambiguity because both are in the same namespace.
1180 | (DefKind::Fn | DefKind::AssocFn, Some(Disambiguator::Kind(DefKind::Fn)))
1181 // These are namespaces; allow anything in the namespace to match
1182 | (_, Some(Disambiguator::Namespace(_)))
1183 // If no disambiguator given, allow anything
1185 // All of these are valid, so do nothing
1187 (actual, Some(Disambiguator::Kind(expected))) if actual == expected => {}
1188 (_, Some(specified @ Disambiguator::Kind(_) | specified @ Disambiguator::Primitive)) => {
1189 self.report_disambiguator_mismatch(path_str,ori_link,specified, Res::Def(kind, id),diag_info);
1194 // item can be non-local e.g. when using #[doc(primitive = "pointer")]
1195 if let Some((src_id, dst_id)) = id
1197 // The `expect_def_id()` should be okay because `local_def_id_to_hir_id`
1198 // would presumably panic if a fake `DefIndex` were passed.
1199 .and_then(|dst_id| {
1200 item.item_id.expect_def_id().as_local().map(|src_id| (src_id, dst_id))
1203 if self.cx.tcx.privacy_access_levels(()).is_exported(src_id)
1204 && !self.cx.tcx.privacy_access_levels(()).is_exported(dst_id)
1206 privacy_error(self.cx, diag_info, path_str);
1213 fn report_disambiguator_mismatch(
1216 ori_link: &MarkdownLink,
1217 specified: Disambiguator,
1219 diag_info: &DiagnosticInfo<'_>,
1221 // The resolved item did not match the disambiguator; give a better error than 'not found'
1222 let msg = format!("incompatible link kind for `{}`", path_str);
1223 let callback = |diag: &mut Diagnostic, sp: Option<rustc_span::Span>| {
1225 "this link resolved to {} {}, which is not {} {}",
1228 specified.article(),
1231 if let Some(sp) = sp {
1232 diag.span_label(sp, ¬e);
1236 suggest_disambiguator(resolved, diag, path_str, &ori_link.link, sp);
1238 report_diagnostic(self.cx.tcx, BROKEN_INTRA_DOC_LINKS, &msg, diag_info, callback);
1241 fn report_rawptr_assoc_feature_gate(&self, dox: &str, ori_link: &MarkdownLink, item: &Item) {
1243 super::source_span_for_markdown_range(self.cx.tcx, dox, &ori_link.range, &item.attrs)
1244 .unwrap_or_else(|| item.attr_span(self.cx.tcx));
1245 rustc_session::parse::feature_err(
1246 &self.cx.tcx.sess.parse_sess,
1247 sym::intra_doc_pointers,
1249 "linking to associated items of raw pointers is experimental",
1251 .note("rustdoc does not allow disambiguating between `*const` and `*mut`, and pointers are unstable until it does")
1255 fn resolve_with_disambiguator_cached(
1257 key: ResolutionInfo,
1258 diag: DiagnosticInfo<'_>,
1259 // If errors are cached then they are only reported on first ocurrence
1260 // which we want in some cases but not in others.
1262 ) -> Option<(Res, Option<UrlFragment>)> {
1263 if let Some(res) = self.visited_links.get(&key) {
1264 if res.is_some() || cache_errors {
1269 let res = self.resolve_with_disambiguator(&key, diag.clone()).and_then(|(res, def_id)| {
1270 let fragment = match (&key.extra_fragment, def_id) {
1271 (Some(_), Some(def_id)) => {
1272 report_anchor_conflict(self.cx, diag, def_id);
1275 (Some(u_frag), None) => Some(UrlFragment::UserWritten(u_frag.clone())),
1276 (None, Some(def_id)) => Some(UrlFragment::Item(def_id)),
1277 (None, None) => None,
1279 Some((res, fragment))
1282 if res.is_some() || cache_errors {
1283 self.visited_links.insert(key, res.clone());
1288 /// After parsing the disambiguator, resolve the main part of the link.
1289 // FIXME(jynelson): wow this is just so much
1290 fn resolve_with_disambiguator(
1292 key: &ResolutionInfo,
1293 diag: DiagnosticInfo<'_>,
1294 ) -> Option<(Res, Option<DefId>)> {
1295 let disambiguator = key.dis;
1296 let path_str = &key.path_str;
1297 let item_id = key.item_id;
1298 let base_node = key.module_id;
1300 match disambiguator.map(Disambiguator::ns) {
1301 Some(expected_ns) => {
1302 match self.resolve(path_str, expected_ns, item_id, base_node) {
1303 Ok(res) => Some(res),
1305 // We only looked in one namespace. Try to give a better error if possible.
1306 // FIXME: really it should be `resolution_failure` that does this, not `resolve_with_disambiguator`.
1307 // See https://github.com/rust-lang/rust/pull/76955#discussion_r493953382 for a good approach.
1308 let mut err = ResolutionFailure::NotResolved(err);
1309 for other_ns in [TypeNS, ValueNS, MacroNS] {
1310 if other_ns != expected_ns {
1312 self.resolve(path_str, other_ns, item_id, base_node)
1314 err = ResolutionFailure::WrongNamespace {
1315 res: full_res(self.cx.tcx, res),
1322 resolution_failure(self, diag, path_str, disambiguator, smallvec![err])
1328 let mut candidate = |ns| {
1329 self.resolve(path_str, ns, item_id, base_node)
1330 .map_err(ResolutionFailure::NotResolved)
1333 let candidates = PerNS {
1334 macro_ns: candidate(MacroNS),
1335 type_ns: candidate(TypeNS),
1336 value_ns: candidate(ValueNS).and_then(|(res, def_id)| {
1338 // Constructors are picked up in the type namespace.
1339 Res::Def(DefKind::Ctor(..), _) => {
1340 Err(ResolutionFailure::WrongNamespace { res, expected_ns: TypeNS })
1342 _ => Ok((res, def_id)),
1347 let len = candidates.iter().filter(|res| res.is_ok()).count();
1350 return resolution_failure(
1355 candidates.into_iter().filter_map(|res| res.err()).collect(),
1360 Some(candidates.into_iter().find_map(|res| res.ok()).unwrap())
1361 } else if len == 2 && is_derive_trait_collision(&candidates) {
1362 Some(candidates.type_ns.unwrap())
1364 let ignore_macro = is_derive_trait_collision(&candidates);
1365 // If we're reporting an ambiguity, don't mention the namespaces that failed
1366 let mut candidates =
1367 candidates.map(|candidate| candidate.ok().map(|(res, _)| res));
1369 candidates.macro_ns = None;
1371 ambiguity_error(self.cx, diag, path_str, candidates.present_items().collect());
1379 /// Get the section of a link between the backticks,
1380 /// or the whole link if there aren't any backticks.
1388 fn range_between_backticks(ori_link: &MarkdownLink) -> Range<usize> {
1389 let after_first_backtick_group = ori_link.link.bytes().position(|b| b != b'`').unwrap_or(0);
1390 let before_second_backtick_group = ori_link
1393 .skip(after_first_backtick_group)
1394 .position(|b| b == b'`')
1395 .unwrap_or(ori_link.link.len());
1396 (ori_link.range.start + after_first_backtick_group)
1397 ..(ori_link.range.start + before_second_backtick_group)
1400 /// Returns true if we should ignore `link` due to it being unlikely
1401 /// that it is an intra-doc link. `link` should still have disambiguators
1402 /// if there were any.
1404 /// The difference between this and [`should_ignore_link()`] is that this
1405 /// check should only be used on links that still have disambiguators.
1406 fn should_ignore_link_with_disambiguators(link: &str) -> bool {
1407 link.contains(|ch: char| !(ch.is_alphanumeric() || ":_<>, !*&;@()".contains(ch)))
1410 /// Returns true if we should ignore `path_str` due to it being unlikely
1411 /// that it is an intra-doc link.
1412 fn should_ignore_link(path_str: &str) -> bool {
1413 path_str.contains(|ch: char| !(ch.is_alphanumeric() || ":_<>, !*&;".contains(ch)))
1416 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
1417 /// Disambiguators for a link.
1418 enum Disambiguator {
1421 /// This is buggy, see <https://github.com/rust-lang/rust/pull/77875#discussion_r503583103>
1423 /// `struct@` or `f()`
1426 Namespace(Namespace),
1429 impl Disambiguator {
1430 /// Given a link, parse and return `(disambiguator, path_str, link_text)`.
1432 /// This returns `Ok(Some(...))` if a disambiguator was found,
1433 /// `Ok(None)` if no disambiguator was found, or `Err(...)`
1434 /// if there was a problem with the disambiguator.
1435 fn from_str(link: &str) -> Result<Option<(Self, &str, &str)>, (String, Range<usize>)> {
1436 use Disambiguator::{Kind, Namespace as NS, Primitive};
1438 if let Some(idx) = link.find('@') {
1439 let (prefix, rest) = link.split_at(idx);
1440 let d = match prefix {
1441 "struct" => Kind(DefKind::Struct),
1442 "enum" => Kind(DefKind::Enum),
1443 "trait" => Kind(DefKind::Trait),
1444 "union" => Kind(DefKind::Union),
1445 "module" | "mod" => Kind(DefKind::Mod),
1446 "const" | "constant" => Kind(DefKind::Const),
1447 "static" => Kind(DefKind::Static(Mutability::Not)),
1448 "function" | "fn" | "method" => Kind(DefKind::Fn),
1449 "derive" => Kind(DefKind::Macro(MacroKind::Derive)),
1450 "type" => NS(Namespace::TypeNS),
1451 "value" => NS(Namespace::ValueNS),
1452 "macro" => NS(Namespace::MacroNS),
1453 "prim" | "primitive" => Primitive,
1454 _ => return Err((format!("unknown disambiguator `{}`", prefix), 0..idx)),
1456 Ok(Some((d, &rest[1..], &rest[1..])))
1459 ("!()", DefKind::Macro(MacroKind::Bang)),
1460 ("!{}", DefKind::Macro(MacroKind::Bang)),
1461 ("![]", DefKind::Macro(MacroKind::Bang)),
1462 ("()", DefKind::Fn),
1463 ("!", DefKind::Macro(MacroKind::Bang)),
1465 for (suffix, kind) in suffixes {
1466 if let Some(path_str) = link.strip_suffix(suffix) {
1467 // Avoid turning `!` or `()` into an empty string
1468 if !path_str.is_empty() {
1469 return Ok(Some((Kind(kind), path_str, link)));
1477 fn ns(self) -> Namespace {
1479 Self::Namespace(n) => n,
1481 k.ns().expect("only DefKinds with a valid namespace can be disambiguators")
1483 Self::Primitive => TypeNS,
1487 fn article(self) -> &'static str {
1489 Self::Namespace(_) => panic!("article() doesn't make sense for namespaces"),
1490 Self::Kind(k) => k.article(),
1491 Self::Primitive => "a",
1495 fn descr(self) -> &'static str {
1497 Self::Namespace(n) => n.descr(),
1498 // HACK(jynelson): the source of `DefKind::descr` only uses the DefId for
1499 // printing "module" vs "crate" so using the wrong ID is not a huge problem
1500 Self::Kind(k) => k.descr(CRATE_DEF_ID.to_def_id()),
1501 Self::Primitive => "builtin type",
1506 /// A suggestion to show in a diagnostic.
1509 Prefix(&'static str),
1514 /// `foo` without any disambiguator
1515 RemoveDisambiguator,
1519 fn descr(&self) -> Cow<'static, str> {
1521 Self::Prefix(x) => format!("prefix with `{}@`", x).into(),
1522 Self::Function => "add parentheses".into(),
1523 Self::Macro => "add an exclamation mark".into(),
1524 Self::RemoveDisambiguator => "remove the disambiguator".into(),
1528 fn as_help(&self, path_str: &str) -> String {
1529 // FIXME: if this is an implied shortcut link, it's bad style to suggest `@`
1531 Self::Prefix(prefix) => format!("{}@{}", prefix, path_str),
1532 Self::Function => format!("{}()", path_str),
1533 Self::Macro => format!("{}!", path_str),
1534 Self::RemoveDisambiguator => path_str.into(),
1542 sp: rustc_span::Span,
1543 ) -> Vec<(rustc_span::Span, String)> {
1544 let inner_sp = match ori_link.find('(') {
1545 Some(index) => sp.with_hi(sp.lo() + BytePos(index as _)),
1548 let inner_sp = match ori_link.find('!') {
1549 Some(index) => inner_sp.with_hi(inner_sp.lo() + BytePos(index as _)),
1552 let inner_sp = match ori_link.find('@') {
1553 Some(index) => inner_sp.with_lo(inner_sp.lo() + BytePos(index as u32 + 1)),
1557 Self::Prefix(prefix) => {
1558 // FIXME: if this is an implied shortcut link, it's bad style to suggest `@`
1559 let mut sugg = vec![(sp.with_hi(inner_sp.lo()), format!("{}@", prefix))];
1560 if sp.hi() != inner_sp.hi() {
1561 sugg.push((inner_sp.shrink_to_hi().with_hi(sp.hi()), String::new()));
1566 let mut sugg = vec![(inner_sp.shrink_to_hi().with_hi(sp.hi()), "()".to_string())];
1567 if sp.lo() != inner_sp.lo() {
1568 sugg.push((inner_sp.shrink_to_lo().with_lo(sp.lo()), String::new()));
1573 let mut sugg = vec![(inner_sp.shrink_to_hi(), "!".to_string())];
1574 if sp.lo() != inner_sp.lo() {
1575 sugg.push((inner_sp.shrink_to_lo().with_lo(sp.lo()), String::new()));
1579 Self::RemoveDisambiguator => vec![(sp, path_str.into())],
1584 /// Reports a diagnostic for an intra-doc link.
1586 /// If no link range is provided, or the source span of the link cannot be determined, the span of
1587 /// the entire documentation block is used for the lint. If a range is provided but the span
1588 /// calculation fails, a note is added to the diagnostic pointing to the link in the markdown.
1590 /// The `decorate` callback is invoked in all cases to allow further customization of the
1591 /// diagnostic before emission. If the span of the link was able to be determined, the second
1592 /// parameter of the callback will contain it, and the primary span of the diagnostic will be set
1594 fn report_diagnostic(
1596 lint: &'static Lint,
1598 DiagnosticInfo { item, ori_link: _, dox, link_range }: &DiagnosticInfo<'_>,
1599 decorate: impl FnOnce(&mut Diagnostic, Option<rustc_span::Span>),
1601 let Some(hir_id) = DocContext::as_local_hir_id(tcx, item.item_id)
1603 // If non-local, no need to check anything.
1604 info!("ignoring warning from parent crate: {}", msg);
1608 let sp = item.attr_span(tcx);
1610 tcx.struct_span_lint_hir(lint, hir_id, sp, |lint| {
1611 let mut diag = lint.build(msg);
1614 super::source_span_for_markdown_range(tcx, dox, link_range, &item.attrs).map(|sp| {
1615 if dox.as_bytes().get(link_range.start) == Some(&b'`')
1616 && dox.as_bytes().get(link_range.end - 1) == Some(&b'`')
1618 sp.with_lo(sp.lo() + BytePos(1)).with_hi(sp.hi() - BytePos(1))
1624 if let Some(sp) = span {
1627 // blah blah blah\nblah\nblah [blah] blah blah\nblah blah
1630 // last_new_line_offset
1631 let last_new_line_offset = dox[..link_range.start].rfind('\n').map_or(0, |n| n + 1);
1632 let line = dox[last_new_line_offset..].lines().next().unwrap_or("");
1634 // Print the line containing the `link_range` and manually mark it with '^'s.
1636 "the link appears in this line:\n\n{line}\n\
1637 {indicator: <before$}{indicator:^<found$}",
1640 before = link_range.start - last_new_line_offset,
1641 found = link_range.len(),
1645 decorate(&mut diag, span);
1651 /// Reports a link that failed to resolve.
1653 /// This also tries to resolve any intermediate path segments that weren't
1654 /// handled earlier. For example, if passed `Item::Crate(std)` and `path_str`
1655 /// `std::io::Error::x`, this will resolve `std::io::Error`.
1656 fn resolution_failure(
1657 collector: &mut LinkCollector<'_, '_>,
1658 diag_info: DiagnosticInfo<'_>,
1660 disambiguator: Option<Disambiguator>,
1661 kinds: SmallVec<[ResolutionFailure<'_>; 3]>,
1662 ) -> Option<(Res, Option<DefId>)> {
1663 let tcx = collector.cx.tcx;
1664 let mut recovered_res = None;
1667 BROKEN_INTRA_DOC_LINKS,
1668 &format!("unresolved link to `{}`", path_str),
1671 let item = |res: Res| format!("the {} `{}`", res.descr(), res.name(tcx),);
1672 let assoc_item_not_allowed = |res: Res| {
1673 let name = res.name(tcx);
1675 "`{}` is {} {}, not a module or type, and cannot have associated items",
1681 // ignore duplicates
1682 let mut variants_seen = SmallVec::<[_; 3]>::new();
1683 for mut failure in kinds {
1684 let variant = std::mem::discriminant(&failure);
1685 if variants_seen.contains(&variant) {
1688 variants_seen.push(variant);
1690 if let ResolutionFailure::NotResolved(UnresolvedPath {
1699 let item_id = *item_id;
1700 let module_id = *module_id;
1701 // FIXME(jynelson): this might conflict with my `Self` fix in #76467
1702 // FIXME: maybe use itertools `collect_tuple` instead?
1703 fn split(path: &str) -> Option<(&str, &str)> {
1704 let mut splitter = path.rsplitn(2, "::");
1705 splitter.next().and_then(|right| splitter.next().map(|left| (left, right)))
1708 // Check if _any_ parent of the path gets resolved.
1709 // If so, report it and say the first which failed; if not, say the first path segment didn't resolve.
1710 let mut name = path_str;
1712 let Some((start, end)) = split(name) else {
1713 // avoid bug that marked [Quux::Z] as missing Z, not Quux
1714 if partial_res.is_none() {
1715 *unresolved = name.into();
1720 for ns in [TypeNS, ValueNS, MacroNS] {
1721 if let Ok(res) = collector.resolve(start, ns, item_id, module_id) {
1722 debug!("found partial_res={:?}", res);
1723 *partial_res = Some(full_res(collector.cx.tcx, res));
1724 *unresolved = end.into();
1728 *unresolved = end.into();
1731 let last_found_module = match *partial_res {
1732 Some(Res::Def(DefKind::Mod, id)) => Some(id),
1733 None => Some(module_id),
1736 // See if this was a module: `[path]` or `[std::io::nope]`
1737 if let Some(module) = last_found_module {
1738 let note = if partial_res.is_some() {
1739 // Part of the link resolved; e.g. `std::io::nonexistent`
1740 let module_name = tcx.item_name(module);
1741 format!("no item named `{}` in module `{}`", unresolved, module_name)
1743 // None of the link resolved; e.g. `Notimported`
1744 format!("no item named `{}` in scope", unresolved)
1746 if let Some(span) = sp {
1747 diag.span_label(span, ¬e);
1752 if !path_str.contains("::") {
1753 if disambiguator.map_or(true, |d| d.ns() == MacroNS)
1754 && let Some(&res) = collector.cx.resolver_caches.all_macro_rules
1755 .get(&Symbol::intern(path_str))
1758 "`macro_rules` named `{path_str}` exists in this crate, \
1759 but it is not in scope at this link's location"
1761 recovered_res = res.try_into().ok().map(|res| (res, None));
1763 // If the link has `::` in it, assume it was meant to be an
1764 // intra-doc link. Otherwise, the `[]` might be unrelated.
1765 diag.help("to escape `[` and `]` characters, \
1766 add '\\' before them like `\\[` or `\\]`");
1773 // Otherwise, it must be an associated item or variant
1774 let res = partial_res.expect("None case was handled by `last_found_module`");
1775 let name = res.name(tcx);
1776 let kind = match res {
1777 Res::Def(kind, _) => Some(kind),
1778 Res::Primitive(_) => None,
1780 let path_description = if let Some(kind) = kind {
1782 Mod | ForeignMod => "inner item",
1783 Struct => "field or associated item",
1784 Enum | Union => "variant or associated item",
1802 let note = assoc_item_not_allowed(res);
1803 if let Some(span) = sp {
1804 diag.span_label(span, ¬e);
1810 Trait | TyAlias | ForeignTy | OpaqueTy | TraitAlias | TyParam
1811 | Static(_) => "associated item",
1812 Impl | GlobalAsm => unreachable!("not a path"),
1818 "the {} `{}` has no {} named `{}`",
1821 disambiguator.map_or(path_description, |d| d.descr()),
1824 if let Some(span) = sp {
1825 diag.span_label(span, ¬e);
1832 let note = match failure {
1833 ResolutionFailure::NotResolved { .. } => unreachable!("handled above"),
1834 ResolutionFailure::WrongNamespace { res, expected_ns } => {
1835 suggest_disambiguator(res, diag, path_str, diag_info.ori_link, sp);
1838 "this link resolves to {}, which is not in the {} namespace",
1844 if let Some(span) = sp {
1845 diag.span_label(span, ¬e);
1856 fn report_multiple_anchors(cx: &DocContext<'_>, diag_info: DiagnosticInfo<'_>) {
1857 let msg = format!("`{}` contains multiple anchors", diag_info.ori_link);
1858 anchor_failure(cx, diag_info, &msg, 1)
1861 fn report_anchor_conflict(cx: &DocContext<'_>, diag_info: DiagnosticInfo<'_>, def_id: DefId) {
1862 let (link, kind) = (diag_info.ori_link, Res::from_def_id(cx.tcx, def_id).descr());
1863 let msg = format!("`{link}` contains an anchor, but links to {kind}s are already anchored");
1864 anchor_failure(cx, diag_info, &msg, 0)
1867 /// Report an anchor failure.
1869 cx: &DocContext<'_>,
1870 diag_info: DiagnosticInfo<'_>,
1874 report_diagnostic(cx.tcx, BROKEN_INTRA_DOC_LINKS, msg, &diag_info, |diag, sp| {
1875 if let Some(mut sp) = sp {
1876 if let Some((fragment_offset, _)) =
1877 diag_info.ori_link.char_indices().filter(|(_, x)| *x == '#').nth(anchor_idx)
1879 sp = sp.with_lo(sp.lo() + BytePos(fragment_offset as _));
1881 diag.span_label(sp, "invalid anchor");
1886 /// Report an error in the link disambiguator.
1887 fn disambiguator_error(
1888 cx: &DocContext<'_>,
1889 mut diag_info: DiagnosticInfo<'_>,
1890 disambiguator_range: Range<usize>,
1893 diag_info.link_range = disambiguator_range;
1894 report_diagnostic(cx.tcx, BROKEN_INTRA_DOC_LINKS, msg, &diag_info, |diag, _sp| {
1896 "see {}/rustdoc/linking-to-items-by-name.html#namespaces-and-disambiguators for more info about disambiguators",
1897 crate::DOC_RUST_LANG_ORG_CHANNEL
1903 fn report_malformed_generics(
1904 cx: &DocContext<'_>,
1905 diag_info: DiagnosticInfo<'_>,
1906 err: MalformedGenerics,
1911 BROKEN_INTRA_DOC_LINKS,
1912 &format!("unresolved link to `{}`", path_str),
1915 let note = match err {
1916 MalformedGenerics::UnbalancedAngleBrackets => "unbalanced angle brackets",
1917 MalformedGenerics::MissingType => "missing type for generic parameters",
1918 MalformedGenerics::HasFullyQualifiedSyntax => {
1920 "see https://github.com/rust-lang/rust/issues/74563 for more information",
1922 "fully-qualified syntax is unsupported"
1924 MalformedGenerics::InvalidPathSeparator => "has invalid path separator",
1925 MalformedGenerics::TooManyAngleBrackets => "too many angle brackets",
1926 MalformedGenerics::EmptyAngleBrackets => "empty angle brackets",
1928 if let Some(span) = sp {
1929 diag.span_label(span, note);
1937 /// Report an ambiguity error, where there were multiple possible resolutions.
1939 cx: &DocContext<'_>,
1940 diag_info: DiagnosticInfo<'_>,
1942 candidates: Vec<Res>,
1944 let mut msg = format!("`{}` is ", path_str);
1946 match candidates.as_slice() {
1947 [first_def, second_def] => {
1949 "both {} {} and {} {}",
1950 first_def.article(),
1952 second_def.article(),
1957 let mut candidates = candidates.iter().peekable();
1958 while let Some(res) = candidates.next() {
1959 if candidates.peek().is_some() {
1960 msg += &format!("{} {}, ", res.article(), res.descr());
1962 msg += &format!("and {} {}", res.article(), res.descr());
1968 report_diagnostic(cx.tcx, BROKEN_INTRA_DOC_LINKS, &msg, &diag_info, |diag, sp| {
1969 if let Some(sp) = sp {
1970 diag.span_label(sp, "ambiguous link");
1972 diag.note("ambiguous link");
1975 for res in candidates {
1976 suggest_disambiguator(res, diag, path_str, diag_info.ori_link, sp);
1981 /// In case of an ambiguity or mismatched disambiguator, suggest the correct
1983 fn suggest_disambiguator(
1985 diag: &mut Diagnostic,
1988 sp: Option<rustc_span::Span>,
1990 let suggestion = res.disambiguator_suggestion();
1991 let help = format!("to link to the {}, {}", res.descr(), suggestion.descr());
1993 if let Some(sp) = sp {
1994 let mut spans = suggestion.as_help_span(path_str, ori_link, sp);
1995 if spans.len() > 1 {
1996 diag.multipart_suggestion(&help, spans, Applicability::MaybeIncorrect);
1998 let (sp, suggestion_text) = spans.pop().unwrap();
1999 diag.span_suggestion_verbose(sp, &help, suggestion_text, Applicability::MaybeIncorrect);
2002 diag.help(&format!("{}: {}", help, suggestion.as_help(path_str)));
2006 /// Report a link from a public item to a private one.
2007 fn privacy_error(cx: &DocContext<'_>, diag_info: &DiagnosticInfo<'_>, path_str: &str) {
2009 let item_name = match diag_info.item.name {
2014 None => "<unknown>",
2017 format!("public documentation for `{}` links to private item `{}`", item_name, path_str);
2019 report_diagnostic(cx.tcx, PRIVATE_INTRA_DOC_LINKS, &msg, diag_info, |diag, sp| {
2020 if let Some(sp) = sp {
2021 diag.span_label(sp, "this item is private");
2024 let note_msg = if cx.render_options.document_private {
2025 "this link resolves only because you passed `--document-private-items`, but will break without"
2027 "this link will resolve properly if you pass `--document-private-items`"
2029 diag.note(note_msg);
2033 /// Resolve a primitive type or value.
2034 fn resolve_primitive(path_str: &str, ns: Namespace) -> Option<Res> {
2038 use PrimitiveType::*;
2039 let prim = match path_str {
2055 "bool" | "true" | "false" => Bool,
2056 "str" | "&str" => Str,
2057 // See #80181 for why these don't have symbols associated.
2062 "pointer" | "*const" | "*mut" => RawPointer,
2063 "reference" | "&" | "&mut" => Reference,
2065 "never" | "!" => Never,
2068 debug!("resolved primitives {:?}", prim);
2069 Some(Res::Primitive(prim))
2072 fn strip_generics_from_path(path_str: &str) -> Result<String, MalformedGenerics> {
2073 let mut stripped_segments = vec![];
2074 let mut path = path_str.chars().peekable();
2075 let mut segment = Vec::new();
2077 while let Some(chr) = path.next() {
2080 if path.next_if_eq(&':').is_some() {
2081 let stripped_segment =
2082 strip_generics_from_path_segment(mem::take(&mut segment))?;
2083 if !stripped_segment.is_empty() {
2084 stripped_segments.push(stripped_segment);
2087 return Err(MalformedGenerics::InvalidPathSeparator);
2095 return Err(MalformedGenerics::TooManyAngleBrackets);
2098 return Err(MalformedGenerics::EmptyAngleBrackets);
2103 while let Some(chr) = path.next_if(|c| *c != '>') {
2110 _ => segment.push(chr),
2112 trace!("raw segment: {:?}", segment);
2115 if !segment.is_empty() {
2116 let stripped_segment = strip_generics_from_path_segment(segment)?;
2117 if !stripped_segment.is_empty() {
2118 stripped_segments.push(stripped_segment);
2122 debug!("path_str: {:?}\nstripped segments: {:?}", path_str, &stripped_segments);
2124 let stripped_path = stripped_segments.join("::");
2126 if !stripped_path.is_empty() { Ok(stripped_path) } else { Err(MalformedGenerics::MissingType) }
2129 fn strip_generics_from_path_segment(segment: Vec<char>) -> Result<String, MalformedGenerics> {
2130 let mut stripped_segment = String::new();
2131 let mut param_depth = 0;
2133 let mut latest_generics_chunk = String::new();
2138 latest_generics_chunk.clear();
2139 } else if c == '>' {
2141 if latest_generics_chunk.contains(" as ") {
2142 // The segment tries to use fully-qualified syntax, which is currently unsupported.
2143 // Give a helpful error message instead of completely ignoring the angle brackets.
2144 return Err(MalformedGenerics::HasFullyQualifiedSyntax);
2147 if param_depth == 0 {
2148 stripped_segment.push(c);
2150 latest_generics_chunk.push(c);
2155 if param_depth == 0 {
2156 Ok(stripped_segment)
2158 // The segment has unbalanced angle brackets, e.g. `Vec<T` or `Vec<T>>`
2159 Err(MalformedGenerics::UnbalancedAngleBrackets)