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 `::`, assuming {} 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), ret)]
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 Some(tcx.associated_item(impl_assoc_id))
766 /// Given a type, return all trait impls in scope in `module` for that type.
767 /// Returns a set of pairs of `(impl_id, trait_id)`.
769 /// NOTE: this cannot be a query because more traits could be available when more crates are compiled!
770 /// So it is not stable to serialize cross-crate.
771 #[instrument(level = "debug", skip(cx))]
772 fn trait_impls_for<'a>(
773 cx: &mut DocContext<'a>,
776 ) -> FxHashSet<(DefId, DefId)> {
778 let iter = cx.resolver_caches.traits_in_scope[&module].iter().flat_map(|trait_candidate| {
779 let trait_ = trait_candidate.def_id;
780 trace!("considering explicit impl for trait {:?}", trait_);
782 // Look at each trait implementation to see if it's an impl for `did`
783 tcx.find_map_relevant_impl(trait_, ty, |impl_| {
784 let trait_ref = tcx.impl_trait_ref(impl_).expect("this is not an inherent impl");
785 // Check if these are the same type.
786 let impl_type = trait_ref.self_ty();
788 "comparing type {} with kind {:?} against type {:?}",
793 // Fast path: if this is a primitive simple `==` will work
794 // NOTE: the `match` is necessary; see #92662.
795 // this allows us to ignore generics because the user input
796 // may not include the generic placeholders
797 // e.g. this allows us to match Foo (user comment) with Foo<T> (actual type)
798 let saw_impl = impl_type == ty
799 || match (impl_type.kind(), ty.kind()) {
800 (ty::Adt(impl_def, _), ty::Adt(ty_def, _)) => {
801 debug!("impl def_id: {:?}, ty def_id: {:?}", impl_def.did(), ty_def.did());
802 impl_def.did() == ty_def.did()
807 if saw_impl { Some((impl_, trait_)) } else { None }
813 /// Check for resolve collisions between a trait and its derive.
815 /// These are common and we should just resolve to the trait in that case.
816 fn is_derive_trait_collision<T>(ns: &PerNS<Result<(Res, T), ResolutionFailure<'_>>>) -> bool {
820 type_ns: Ok((Res::Def(DefKind::Trait, _), _)),
821 macro_ns: Ok((Res::Def(DefKind::Macro(MacroKind::Derive), _), _)),
827 impl<'a, 'tcx> DocVisitor for LinkCollector<'a, 'tcx> {
828 fn visit_item(&mut self, item: &Item) {
830 item.item_id.as_def_id().and_then(|did| find_nearest_parent_module(self.cx.tcx, did));
831 if parent_node.is_some() {
832 trace!("got parent node for {:?} {:?}, id {:?}", item.type_(), item.name, item.item_id);
835 let inner_docs = item.inner_docs(self.cx.tcx);
837 if item.is_mod() && inner_docs {
838 self.mod_ids.push(item.item_id.expect_def_id());
841 // We want to resolve in the lexical scope of the documentation.
842 // In the presence of re-exports, this is not the same as the module of the item.
843 // Rather than merging all documentation into one, resolve it one attribute at a time
844 // so we know which module it came from.
845 for (parent_module, doc) in item.attrs.prepare_to_doc_link_resolution() {
846 if !may_have_doc_links(&doc) {
849 debug!("combined_docs={}", doc);
850 // NOTE: if there are links that start in one crate and end in another, this will not resolve them.
851 // This is a degenerate case and it's not supported by rustdoc.
852 let parent_node = parent_module.or(parent_node);
853 let mut tmp_links = self
858 .expect("`markdown_links` are already borrowed");
859 if !tmp_links.contains_key(&doc) {
860 tmp_links.insert(doc.clone(), preprocessed_markdown_links(&doc));
862 for md_link in &tmp_links[&doc] {
863 let link = self.resolve_link(item, &doc, parent_node, md_link);
864 if let Some(link) = link {
865 self.cx.cache.intra_doc_links.entry(item.item_id).or_default().push(link);
868 self.cx.resolver_caches.markdown_links = Some(tmp_links);
873 self.mod_ids.push(item.item_id.expect_def_id());
876 self.visit_item_recur(item);
879 self.visit_item_recur(item)
884 enum PreprocessingError {
885 /// User error: `[std#x#y]` is not valid
887 Disambiguator(Range<usize>, String),
888 MalformedGenerics(MalformedGenerics, String),
891 impl PreprocessingError {
892 fn report(&self, cx: &DocContext<'_>, diag_info: DiagnosticInfo<'_>) {
894 PreprocessingError::MultipleAnchors => report_multiple_anchors(cx, diag_info),
895 PreprocessingError::Disambiguator(range, msg) => {
896 disambiguator_error(cx, diag_info, range.clone(), msg)
898 PreprocessingError::MalformedGenerics(err, path_str) => {
899 report_malformed_generics(cx, diag_info, *err, path_str)
906 struct PreprocessingInfo {
908 disambiguator: Option<Disambiguator>,
909 extra_fragment: Option<String>,
913 // Not a typedef to avoid leaking several private structures from this module.
914 pub(crate) struct PreprocessedMarkdownLink(
915 Result<PreprocessingInfo, PreprocessingError>,
920 /// - `None` if the link should be ignored.
921 /// - `Some(Err)` if the link should emit an error
922 /// - `Some(Ok)` if the link is valid
924 /// `link_buffer` is needed for lifetime reasons; it will always be overwritten and the contents ignored.
926 ori_link: &MarkdownLink,
927 ) -> Option<Result<PreprocessingInfo, PreprocessingError>> {
928 // [] is mostly likely not supposed to be a link
929 if ori_link.link.is_empty() {
933 // Bail early for real links.
934 if ori_link.link.contains('/') {
938 let stripped = ori_link.link.replace('`', "");
939 let mut parts = stripped.split('#');
941 let link = parts.next().unwrap();
942 if link.trim().is_empty() {
943 // This is an anchor to an element of the current page, nothing to do in here!
946 let extra_fragment = parts.next();
947 if parts.next().is_some() {
948 // A valid link can't have multiple #'s
949 return Some(Err(PreprocessingError::MultipleAnchors));
952 // Parse and strip the disambiguator from the link, if present.
953 let (disambiguator, path_str, link_text) = match Disambiguator::from_str(link) {
954 Ok(Some((d, path, link_text))) => (Some(d), path.trim(), link_text.trim()),
955 Ok(None) => (None, link.trim(), link.trim()),
956 Err((err_msg, relative_range)) => {
957 // Only report error if we would not have ignored this link. See issue #83859.
958 if !should_ignore_link_with_disambiguators(link) {
959 let no_backticks_range = range_between_backticks(ori_link);
960 let disambiguator_range = (no_backticks_range.start + relative_range.start)
961 ..(no_backticks_range.start + relative_range.end);
962 return Some(Err(PreprocessingError::Disambiguator(disambiguator_range, err_msg)));
969 if should_ignore_link(path_str) {
973 // Strip generics from the path.
974 let path_str = if path_str.contains(['<', '>'].as_slice()) {
975 match strip_generics_from_path(path_str) {
978 debug!("link has malformed generics: {}", path_str);
979 return Some(Err(PreprocessingError::MalformedGenerics(err, path_str.to_owned())));
986 // Sanity check to make sure we don't have any angle brackets after stripping generics.
987 assert!(!path_str.contains(['<', '>'].as_slice()));
989 // The link is not an intra-doc link if it still contains spaces after stripping generics.
990 if path_str.contains(' ') {
994 Some(Ok(PreprocessingInfo {
997 extra_fragment: extra_fragment.map(|frag| frag.to_owned()),
998 link_text: link_text.to_owned(),
1002 fn preprocessed_markdown_links(s: &str) -> Vec<PreprocessedMarkdownLink> {
1003 markdown_links(s, |link| {
1004 preprocess_link(&link).map(|pp_link| PreprocessedMarkdownLink(pp_link, link))
1008 impl LinkCollector<'_, '_> {
1009 /// This is the entry point for resolving an intra-doc link.
1011 /// FIXME(jynelson): this is way too many arguments
1016 parent_node: Option<DefId>,
1017 link: &PreprocessedMarkdownLink,
1018 ) -> Option<ItemLink> {
1019 let PreprocessedMarkdownLink(pp_link, ori_link) = link;
1020 trace!("considering link '{}'", ori_link.link);
1022 let diag_info = DiagnosticInfo {
1025 ori_link: &ori_link.link,
1026 link_range: ori_link.range.clone(),
1029 let PreprocessingInfo { path_str, disambiguator, extra_fragment, link_text } =
1030 pp_link.as_ref().map_err(|err| err.report(self.cx, diag_info.clone())).ok()?;
1031 let disambiguator = *disambiguator;
1033 // In order to correctly resolve intra-doc links we need to
1034 // pick a base AST node to work from. If the documentation for
1035 // this module came from an inner comment (//!) then we anchor
1036 // our name resolution *inside* the module. If, on the other
1037 // hand it was an outer comment (///) then we anchor the name
1038 // resolution in the parent module on the basis that the names
1039 // used are more likely to be intended to be parent names. For
1040 // this, we set base_node to None for inner comments since
1041 // we've already pushed this node onto the resolution stack but
1042 // for outer comments we explicitly try and resolve against the
1043 // parent_node first.
1044 let inner_docs = item.inner_docs(self.cx.tcx);
1046 if item.is_mod() && inner_docs { self.mod_ids.last().copied() } else { parent_node };
1047 let module_id = base_node.expect("doc link without parent module");
1049 let (mut res, fragment) = self.resolve_with_disambiguator_cached(
1051 item_id: item.item_id,
1054 path_str: path_str.to_owned(),
1055 extra_fragment: extra_fragment.clone(),
1057 diag_info.clone(), // this struct should really be Copy, but Range is not :(
1058 // For reference-style links we want to report only one error so unsuccessful
1059 // resolutions are cached, for other links we want to report an error every
1060 // time so they are not cached.
1061 matches!(ori_link.kind, LinkType::Reference | LinkType::Shortcut),
1064 // Check for a primitive which might conflict with a module
1065 // Report the ambiguity and require that the user specify which one they meant.
1066 // FIXME: could there ever be a primitive not in the type namespace?
1069 None | Some(Disambiguator::Namespace(Namespace::TypeNS) | Disambiguator::Primitive)
1070 ) && !matches!(res, Res::Primitive(_))
1072 if let Some(prim) = resolve_primitive(path_str, TypeNS) {
1074 if matches!(disambiguator, Some(Disambiguator::Primitive)) {
1077 // `[char]` when a `char` module is in scope
1078 let candidates = vec![res, prim];
1079 ambiguity_error(self.cx, diag_info, path_str, candidates);
1086 Res::Primitive(prim) => {
1087 if let Some(UrlFragment::Item(id)) = fragment {
1088 // We're actually resolving an associated item of a primitive, so we need to
1089 // verify the disambiguator (if any) matches the type of the associated item.
1090 // This case should really follow the same flow as the `Res::Def` branch below,
1091 // but attempting to add a call to `clean::register_res` causes an ICE. @jyn514
1092 // thinks `register_res` is only needed for cross-crate re-exports, but Rust
1093 // doesn't allow statements like `use str::trim;`, making this a (hopefully)
1094 // valid omission. See https://github.com/rust-lang/rust/pull/80660#discussion_r551585677
1095 // for discussion on the matter.
1096 let kind = self.cx.tcx.def_kind(id);
1097 self.verify_disambiguator(
1107 // FIXME: it would be nice to check that the feature gate was enabled in the original crate, not just ignore it altogether.
1108 // However I'm not sure how to check that across crates.
1109 if prim == PrimitiveType::RawPointer
1110 && item.item_id.is_local()
1111 && !self.cx.tcx.features().intra_doc_pointers
1113 self.report_rawptr_assoc_feature_gate(dox, ori_link, item);
1116 match disambiguator {
1117 Some(Disambiguator::Primitive | Disambiguator::Namespace(_)) | None => {}
1119 self.report_disambiguator_mismatch(
1120 path_str, ori_link, other, res, &diag_info,
1128 link: ori_link.link.clone(),
1129 link_text: link_text.clone(),
1130 did: res.def_id(self.cx.tcx),
1134 Res::Def(kind, id) => {
1135 let (kind_for_dis, id_for_dis) = if let Some(UrlFragment::Item(id)) = fragment {
1136 (self.cx.tcx.def_kind(id), id)
1140 self.verify_disambiguator(
1149 let id = clean::register_res(self.cx, rustc_hir::def::Res::Def(kind, id));
1151 link: ori_link.link.clone(),
1152 link_text: link_text.clone(),
1160 fn verify_disambiguator(
1163 ori_link: &MarkdownLink,
1166 disambiguator: Option<Disambiguator>,
1168 diag_info: &DiagnosticInfo<'_>,
1170 debug!("intra-doc link to {} resolved to {:?}", path_str, (kind, id));
1172 // Disallow e.g. linking to enums with `struct@`
1173 debug!("saw kind {:?} with disambiguator {:?}", kind, disambiguator);
1174 match (kind, disambiguator) {
1175 | (DefKind::Const | DefKind::ConstParam | DefKind::AssocConst | DefKind::AnonConst, Some(Disambiguator::Kind(DefKind::Const)))
1176 // NOTE: this allows 'method' to mean both normal functions and associated functions
1177 // This can't cause ambiguity because both are in the same namespace.
1178 | (DefKind::Fn | DefKind::AssocFn, Some(Disambiguator::Kind(DefKind::Fn)))
1179 // These are namespaces; allow anything in the namespace to match
1180 | (_, Some(Disambiguator::Namespace(_)))
1181 // If no disambiguator given, allow anything
1183 // All of these are valid, so do nothing
1185 (actual, Some(Disambiguator::Kind(expected))) if actual == expected => {}
1186 (_, Some(specified @ Disambiguator::Kind(_) | specified @ Disambiguator::Primitive)) => {
1187 self.report_disambiguator_mismatch(path_str,ori_link,specified, Res::Def(kind, id),diag_info);
1192 // item can be non-local e.g. when using #[doc(primitive = "pointer")]
1193 if let Some((src_id, dst_id)) = id
1195 // The `expect_def_id()` should be okay because `local_def_id_to_hir_id`
1196 // would presumably panic if a fake `DefIndex` were passed.
1197 .and_then(|dst_id| {
1198 item.item_id.expect_def_id().as_local().map(|src_id| (src_id, dst_id))
1201 if self.cx.tcx.privacy_access_levels(()).is_exported(src_id)
1202 && !self.cx.tcx.privacy_access_levels(()).is_exported(dst_id)
1204 privacy_error(self.cx, diag_info, path_str);
1211 fn report_disambiguator_mismatch(
1214 ori_link: &MarkdownLink,
1215 specified: Disambiguator,
1217 diag_info: &DiagnosticInfo<'_>,
1219 // The resolved item did not match the disambiguator; give a better error than 'not found'
1220 let msg = format!("incompatible link kind for `{}`", path_str);
1221 let callback = |diag: &mut Diagnostic, sp: Option<rustc_span::Span>| {
1223 "this link resolved to {} {}, which is not {} {}",
1226 specified.article(),
1229 if let Some(sp) = sp {
1230 diag.span_label(sp, ¬e);
1234 suggest_disambiguator(resolved, diag, path_str, &ori_link.link, sp);
1236 report_diagnostic(self.cx.tcx, BROKEN_INTRA_DOC_LINKS, &msg, diag_info, callback);
1239 fn report_rawptr_assoc_feature_gate(&self, dox: &str, ori_link: &MarkdownLink, item: &Item) {
1241 super::source_span_for_markdown_range(self.cx.tcx, dox, &ori_link.range, &item.attrs)
1242 .unwrap_or_else(|| item.attr_span(self.cx.tcx));
1243 rustc_session::parse::feature_err(
1244 &self.cx.tcx.sess.parse_sess,
1245 sym::intra_doc_pointers,
1247 "linking to associated items of raw pointers is experimental",
1249 .note("rustdoc does not allow disambiguating between `*const` and `*mut`, and pointers are unstable until it does")
1253 fn resolve_with_disambiguator_cached(
1255 key: ResolutionInfo,
1256 diag: DiagnosticInfo<'_>,
1257 // If errors are cached then they are only reported on first occurrence
1258 // which we want in some cases but not in others.
1260 ) -> Option<(Res, Option<UrlFragment>)> {
1261 if let Some(res) = self.visited_links.get(&key) {
1262 if res.is_some() || cache_errors {
1267 let res = self.resolve_with_disambiguator(&key, diag.clone()).and_then(|(res, def_id)| {
1268 let fragment = match (&key.extra_fragment, def_id) {
1269 (Some(_), Some(def_id)) => {
1270 report_anchor_conflict(self.cx, diag, def_id);
1273 (Some(u_frag), None) => Some(UrlFragment::UserWritten(u_frag.clone())),
1274 (None, Some(def_id)) => Some(UrlFragment::Item(def_id)),
1275 (None, None) => None,
1277 Some((res, fragment))
1280 if res.is_some() || cache_errors {
1281 self.visited_links.insert(key, res.clone());
1286 /// After parsing the disambiguator, resolve the main part of the link.
1287 // FIXME(jynelson): wow this is just so much
1288 fn resolve_with_disambiguator(
1290 key: &ResolutionInfo,
1291 diag: DiagnosticInfo<'_>,
1292 ) -> Option<(Res, Option<DefId>)> {
1293 let disambiguator = key.dis;
1294 let path_str = &key.path_str;
1295 let item_id = key.item_id;
1296 let base_node = key.module_id;
1298 match disambiguator.map(Disambiguator::ns) {
1299 Some(expected_ns) => {
1300 match self.resolve(path_str, expected_ns, item_id, base_node) {
1301 Ok(res) => Some(res),
1303 // We only looked in one namespace. Try to give a better error if possible.
1304 // FIXME: really it should be `resolution_failure` that does this, not `resolve_with_disambiguator`.
1305 // See https://github.com/rust-lang/rust/pull/76955#discussion_r493953382 for a good approach.
1306 let mut err = ResolutionFailure::NotResolved(err);
1307 for other_ns in [TypeNS, ValueNS, MacroNS] {
1308 if other_ns != expected_ns {
1310 self.resolve(path_str, other_ns, item_id, base_node)
1312 err = ResolutionFailure::WrongNamespace {
1313 res: full_res(self.cx.tcx, res),
1320 resolution_failure(self, diag, path_str, disambiguator, smallvec![err])
1326 let mut candidate = |ns| {
1327 self.resolve(path_str, ns, item_id, base_node)
1328 .map_err(ResolutionFailure::NotResolved)
1331 let candidates = PerNS {
1332 macro_ns: candidate(MacroNS),
1333 type_ns: candidate(TypeNS),
1334 value_ns: candidate(ValueNS).and_then(|(res, def_id)| {
1336 // Constructors are picked up in the type namespace.
1337 Res::Def(DefKind::Ctor(..), _) => {
1338 Err(ResolutionFailure::WrongNamespace { res, expected_ns: TypeNS })
1340 _ => Ok((res, def_id)),
1345 let len = candidates.iter().filter(|res| res.is_ok()).count();
1348 return resolution_failure(
1353 candidates.into_iter().filter_map(|res| res.err()).collect(),
1358 Some(candidates.into_iter().find_map(|res| res.ok()).unwrap())
1359 } else if len == 2 && is_derive_trait_collision(&candidates) {
1360 Some(candidates.type_ns.unwrap())
1362 let ignore_macro = is_derive_trait_collision(&candidates);
1363 // If we're reporting an ambiguity, don't mention the namespaces that failed
1364 let mut candidates =
1365 candidates.map(|candidate| candidate.ok().map(|(res, _)| res));
1367 candidates.macro_ns = None;
1369 ambiguity_error(self.cx, diag, path_str, candidates.present_items().collect());
1377 /// Get the section of a link between the backticks,
1378 /// or the whole link if there aren't any backticks.
1386 fn range_between_backticks(ori_link: &MarkdownLink) -> Range<usize> {
1387 let after_first_backtick_group = ori_link.link.bytes().position(|b| b != b'`').unwrap_or(0);
1388 let before_second_backtick_group = ori_link
1391 .skip(after_first_backtick_group)
1392 .position(|b| b == b'`')
1393 .unwrap_or(ori_link.link.len());
1394 (ori_link.range.start + after_first_backtick_group)
1395 ..(ori_link.range.start + before_second_backtick_group)
1398 /// Returns true if we should ignore `link` due to it being unlikely
1399 /// that it is an intra-doc link. `link` should still have disambiguators
1400 /// if there were any.
1402 /// The difference between this and [`should_ignore_link()`] is that this
1403 /// check should only be used on links that still have disambiguators.
1404 fn should_ignore_link_with_disambiguators(link: &str) -> bool {
1405 link.contains(|ch: char| !(ch.is_alphanumeric() || ":_<>, !*&;@()".contains(ch)))
1408 /// Returns true if we should ignore `path_str` due to it being unlikely
1409 /// that it is an intra-doc link.
1410 fn should_ignore_link(path_str: &str) -> bool {
1411 path_str.contains(|ch: char| !(ch.is_alphanumeric() || ":_<>, !*&;".contains(ch)))
1414 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
1415 /// Disambiguators for a link.
1416 enum Disambiguator {
1419 /// This is buggy, see <https://github.com/rust-lang/rust/pull/77875#discussion_r503583103>
1421 /// `struct@` or `f()`
1424 Namespace(Namespace),
1427 impl Disambiguator {
1428 /// Given a link, parse and return `(disambiguator, path_str, link_text)`.
1430 /// This returns `Ok(Some(...))` if a disambiguator was found,
1431 /// `Ok(None)` if no disambiguator was found, or `Err(...)`
1432 /// if there was a problem with the disambiguator.
1433 fn from_str(link: &str) -> Result<Option<(Self, &str, &str)>, (String, Range<usize>)> {
1434 use Disambiguator::{Kind, Namespace as NS, Primitive};
1436 if let Some(idx) = link.find('@') {
1437 let (prefix, rest) = link.split_at(idx);
1438 let d = match prefix {
1439 "struct" => Kind(DefKind::Struct),
1440 "enum" => Kind(DefKind::Enum),
1441 "trait" => Kind(DefKind::Trait),
1442 "union" => Kind(DefKind::Union),
1443 "module" | "mod" => Kind(DefKind::Mod),
1444 "const" | "constant" => Kind(DefKind::Const),
1445 "static" => Kind(DefKind::Static(Mutability::Not)),
1446 "function" | "fn" | "method" => Kind(DefKind::Fn),
1447 "derive" => Kind(DefKind::Macro(MacroKind::Derive)),
1448 "type" => NS(Namespace::TypeNS),
1449 "value" => NS(Namespace::ValueNS),
1450 "macro" => NS(Namespace::MacroNS),
1451 "prim" | "primitive" => Primitive,
1452 _ => return Err((format!("unknown disambiguator `{}`", prefix), 0..idx)),
1454 Ok(Some((d, &rest[1..], &rest[1..])))
1457 ("!()", DefKind::Macro(MacroKind::Bang)),
1458 ("!{}", DefKind::Macro(MacroKind::Bang)),
1459 ("![]", DefKind::Macro(MacroKind::Bang)),
1460 ("()", DefKind::Fn),
1461 ("!", DefKind::Macro(MacroKind::Bang)),
1463 for (suffix, kind) in suffixes {
1464 if let Some(path_str) = link.strip_suffix(suffix) {
1465 // Avoid turning `!` or `()` into an empty string
1466 if !path_str.is_empty() {
1467 return Ok(Some((Kind(kind), path_str, link)));
1475 fn ns(self) -> Namespace {
1477 Self::Namespace(n) => n,
1479 k.ns().expect("only DefKinds with a valid namespace can be disambiguators")
1481 Self::Primitive => TypeNS,
1485 fn article(self) -> &'static str {
1487 Self::Namespace(_) => panic!("article() doesn't make sense for namespaces"),
1488 Self::Kind(k) => k.article(),
1489 Self::Primitive => "a",
1493 fn descr(self) -> &'static str {
1495 Self::Namespace(n) => n.descr(),
1496 // HACK(jynelson): the source of `DefKind::descr` only uses the DefId for
1497 // printing "module" vs "crate" so using the wrong ID is not a huge problem
1498 Self::Kind(k) => k.descr(CRATE_DEF_ID.to_def_id()),
1499 Self::Primitive => "builtin type",
1504 /// A suggestion to show in a diagnostic.
1507 Prefix(&'static str),
1512 /// `foo` without any disambiguator
1513 RemoveDisambiguator,
1517 fn descr(&self) -> Cow<'static, str> {
1519 Self::Prefix(x) => format!("prefix with `{}@`", x).into(),
1520 Self::Function => "add parentheses".into(),
1521 Self::Macro => "add an exclamation mark".into(),
1522 Self::RemoveDisambiguator => "remove the disambiguator".into(),
1526 fn as_help(&self, path_str: &str) -> String {
1527 // FIXME: if this is an implied shortcut link, it's bad style to suggest `@`
1529 Self::Prefix(prefix) => format!("{}@{}", prefix, path_str),
1530 Self::Function => format!("{}()", path_str),
1531 Self::Macro => format!("{}!", path_str),
1532 Self::RemoveDisambiguator => path_str.into(),
1540 sp: rustc_span::Span,
1541 ) -> Vec<(rustc_span::Span, String)> {
1542 let inner_sp = match ori_link.find('(') {
1543 Some(index) => sp.with_hi(sp.lo() + BytePos(index as _)),
1546 let inner_sp = match ori_link.find('!') {
1547 Some(index) => inner_sp.with_hi(inner_sp.lo() + BytePos(index as _)),
1550 let inner_sp = match ori_link.find('@') {
1551 Some(index) => inner_sp.with_lo(inner_sp.lo() + BytePos(index as u32 + 1)),
1555 Self::Prefix(prefix) => {
1556 // FIXME: if this is an implied shortcut link, it's bad style to suggest `@`
1557 let mut sugg = vec![(sp.with_hi(inner_sp.lo()), format!("{}@", prefix))];
1558 if sp.hi() != inner_sp.hi() {
1559 sugg.push((inner_sp.shrink_to_hi().with_hi(sp.hi()), String::new()));
1564 let mut sugg = vec![(inner_sp.shrink_to_hi().with_hi(sp.hi()), "()".to_string())];
1565 if sp.lo() != inner_sp.lo() {
1566 sugg.push((inner_sp.shrink_to_lo().with_lo(sp.lo()), String::new()));
1571 let mut sugg = vec![(inner_sp.shrink_to_hi(), "!".to_string())];
1572 if sp.lo() != inner_sp.lo() {
1573 sugg.push((inner_sp.shrink_to_lo().with_lo(sp.lo()), String::new()));
1577 Self::RemoveDisambiguator => vec![(sp, path_str.into())],
1582 /// Reports a diagnostic for an intra-doc link.
1584 /// If no link range is provided, or the source span of the link cannot be determined, the span of
1585 /// the entire documentation block is used for the lint. If a range is provided but the span
1586 /// calculation fails, a note is added to the diagnostic pointing to the link in the markdown.
1588 /// The `decorate` callback is invoked in all cases to allow further customization of the
1589 /// diagnostic before emission. If the span of the link was able to be determined, the second
1590 /// parameter of the callback will contain it, and the primary span of the diagnostic will be set
1592 fn report_diagnostic(
1594 lint: &'static Lint,
1596 DiagnosticInfo { item, ori_link: _, dox, link_range }: &DiagnosticInfo<'_>,
1597 decorate: impl FnOnce(&mut Diagnostic, Option<rustc_span::Span>),
1599 let Some(hir_id) = DocContext::as_local_hir_id(tcx, item.item_id)
1601 // If non-local, no need to check anything.
1602 info!("ignoring warning from parent crate: {}", msg);
1606 let sp = item.attr_span(tcx);
1608 tcx.struct_span_lint_hir(lint, hir_id, sp, |lint| {
1609 let mut diag = lint.build(msg);
1612 super::source_span_for_markdown_range(tcx, dox, link_range, &item.attrs).map(|sp| {
1613 if dox.as_bytes().get(link_range.start) == Some(&b'`')
1614 && dox.as_bytes().get(link_range.end - 1) == Some(&b'`')
1616 sp.with_lo(sp.lo() + BytePos(1)).with_hi(sp.hi() - BytePos(1))
1622 if let Some(sp) = span {
1625 // blah blah blah\nblah\nblah [blah] blah blah\nblah blah
1628 // last_new_line_offset
1629 let last_new_line_offset = dox[..link_range.start].rfind('\n').map_or(0, |n| n + 1);
1630 let line = dox[last_new_line_offset..].lines().next().unwrap_or("");
1632 // Print the line containing the `link_range` and manually mark it with '^'s.
1634 "the link appears in this line:\n\n{line}\n\
1635 {indicator: <before$}{indicator:^<found$}",
1638 before = link_range.start - last_new_line_offset,
1639 found = link_range.len(),
1643 decorate(&mut diag, span);
1649 /// Reports a link that failed to resolve.
1651 /// This also tries to resolve any intermediate path segments that weren't
1652 /// handled earlier. For example, if passed `Item::Crate(std)` and `path_str`
1653 /// `std::io::Error::x`, this will resolve `std::io::Error`.
1654 fn resolution_failure(
1655 collector: &mut LinkCollector<'_, '_>,
1656 diag_info: DiagnosticInfo<'_>,
1658 disambiguator: Option<Disambiguator>,
1659 kinds: SmallVec<[ResolutionFailure<'_>; 3]>,
1660 ) -> Option<(Res, Option<DefId>)> {
1661 let tcx = collector.cx.tcx;
1662 let mut recovered_res = None;
1665 BROKEN_INTRA_DOC_LINKS,
1666 &format!("unresolved link to `{}`", path_str),
1669 let item = |res: Res| format!("the {} `{}`", res.descr(), res.name(tcx),);
1670 let assoc_item_not_allowed = |res: Res| {
1671 let name = res.name(tcx);
1673 "`{}` is {} {}, not a module or type, and cannot have associated items",
1679 // ignore duplicates
1680 let mut variants_seen = SmallVec::<[_; 3]>::new();
1681 for mut failure in kinds {
1682 let variant = std::mem::discriminant(&failure);
1683 if variants_seen.contains(&variant) {
1686 variants_seen.push(variant);
1688 if let ResolutionFailure::NotResolved(UnresolvedPath {
1697 let item_id = *item_id;
1698 let module_id = *module_id;
1699 // FIXME(jynelson): this might conflict with my `Self` fix in #76467
1700 // FIXME: maybe use itertools `collect_tuple` instead?
1701 fn split(path: &str) -> Option<(&str, &str)> {
1702 let mut splitter = path.rsplitn(2, "::");
1703 splitter.next().and_then(|right| splitter.next().map(|left| (left, right)))
1706 // Check if _any_ parent of the path gets resolved.
1707 // If so, report it and say the first which failed; if not, say the first path segment didn't resolve.
1708 let mut name = path_str;
1710 let Some((start, end)) = split(name) else {
1711 // avoid bug that marked [Quux::Z] as missing Z, not Quux
1712 if partial_res.is_none() {
1713 *unresolved = name.into();
1718 for ns in [TypeNS, ValueNS, MacroNS] {
1719 if let Ok(res) = collector.resolve(start, ns, item_id, module_id) {
1720 debug!("found partial_res={:?}", res);
1721 *partial_res = Some(full_res(collector.cx.tcx, res));
1722 *unresolved = end.into();
1726 *unresolved = end.into();
1729 let last_found_module = match *partial_res {
1730 Some(Res::Def(DefKind::Mod, id)) => Some(id),
1731 None => Some(module_id),
1734 // See if this was a module: `[path]` or `[std::io::nope]`
1735 if let Some(module) = last_found_module {
1736 let note = if partial_res.is_some() {
1737 // Part of the link resolved; e.g. `std::io::nonexistent`
1738 let module_name = tcx.item_name(module);
1739 format!("no item named `{}` in module `{}`", unresolved, module_name)
1741 // None of the link resolved; e.g. `Notimported`
1742 format!("no item named `{}` in scope", unresolved)
1744 if let Some(span) = sp {
1745 diag.span_label(span, ¬e);
1750 if !path_str.contains("::") {
1751 if disambiguator.map_or(true, |d| d.ns() == MacroNS)
1752 && let Some(&res) = collector.cx.resolver_caches.all_macro_rules
1753 .get(&Symbol::intern(path_str))
1756 "`macro_rules` named `{path_str}` exists in this crate, \
1757 but it is not in scope at this link's location"
1759 recovered_res = res.try_into().ok().map(|res| (res, None));
1761 // If the link has `::` in it, assume it was meant to be an
1762 // intra-doc link. Otherwise, the `[]` might be unrelated.
1763 diag.help("to escape `[` and `]` characters, \
1764 add '\\' before them like `\\[` or `\\]`");
1771 // Otherwise, it must be an associated item or variant
1772 let res = partial_res.expect("None case was handled by `last_found_module`");
1773 let name = res.name(tcx);
1774 let kind = match res {
1775 Res::Def(kind, _) => Some(kind),
1776 Res::Primitive(_) => None,
1778 let path_description = if let Some(kind) = kind {
1780 Mod | ForeignMod => "inner item",
1781 Struct => "field or associated item",
1782 Enum | Union => "variant or associated item",
1800 let note = assoc_item_not_allowed(res);
1801 if let Some(span) = sp {
1802 diag.span_label(span, ¬e);
1808 Trait | TyAlias | ForeignTy | OpaqueTy | TraitAlias | TyParam
1809 | Static(_) => "associated item",
1810 Impl | GlobalAsm => unreachable!("not a path"),
1816 "the {} `{}` has no {} named `{}`",
1819 disambiguator.map_or(path_description, |d| d.descr()),
1822 if let Some(span) = sp {
1823 diag.span_label(span, ¬e);
1830 let note = match failure {
1831 ResolutionFailure::NotResolved { .. } => unreachable!("handled above"),
1832 ResolutionFailure::WrongNamespace { res, expected_ns } => {
1833 suggest_disambiguator(res, diag, path_str, diag_info.ori_link, sp);
1836 "this link resolves to {}, which is not in the {} namespace",
1842 if let Some(span) = sp {
1843 diag.span_label(span, ¬e);
1854 fn report_multiple_anchors(cx: &DocContext<'_>, diag_info: DiagnosticInfo<'_>) {
1855 let msg = format!("`{}` contains multiple anchors", diag_info.ori_link);
1856 anchor_failure(cx, diag_info, &msg, 1)
1859 fn report_anchor_conflict(cx: &DocContext<'_>, diag_info: DiagnosticInfo<'_>, def_id: DefId) {
1860 let (link, kind) = (diag_info.ori_link, Res::from_def_id(cx.tcx, def_id).descr());
1861 let msg = format!("`{link}` contains an anchor, but links to {kind}s are already anchored");
1862 anchor_failure(cx, diag_info, &msg, 0)
1865 /// Report an anchor failure.
1867 cx: &DocContext<'_>,
1868 diag_info: DiagnosticInfo<'_>,
1872 report_diagnostic(cx.tcx, BROKEN_INTRA_DOC_LINKS, msg, &diag_info, |diag, sp| {
1873 if let Some(mut sp) = sp {
1874 if let Some((fragment_offset, _)) =
1875 diag_info.ori_link.char_indices().filter(|(_, x)| *x == '#').nth(anchor_idx)
1877 sp = sp.with_lo(sp.lo() + BytePos(fragment_offset as _));
1879 diag.span_label(sp, "invalid anchor");
1884 /// Report an error in the link disambiguator.
1885 fn disambiguator_error(
1886 cx: &DocContext<'_>,
1887 mut diag_info: DiagnosticInfo<'_>,
1888 disambiguator_range: Range<usize>,
1891 diag_info.link_range = disambiguator_range;
1892 report_diagnostic(cx.tcx, BROKEN_INTRA_DOC_LINKS, msg, &diag_info, |diag, _sp| {
1894 "see {}/rustdoc/linking-to-items-by-name.html#namespaces-and-disambiguators for more info about disambiguators",
1895 crate::DOC_RUST_LANG_ORG_CHANNEL
1901 fn report_malformed_generics(
1902 cx: &DocContext<'_>,
1903 diag_info: DiagnosticInfo<'_>,
1904 err: MalformedGenerics,
1909 BROKEN_INTRA_DOC_LINKS,
1910 &format!("unresolved link to `{}`", path_str),
1913 let note = match err {
1914 MalformedGenerics::UnbalancedAngleBrackets => "unbalanced angle brackets",
1915 MalformedGenerics::MissingType => "missing type for generic parameters",
1916 MalformedGenerics::HasFullyQualifiedSyntax => {
1918 "see https://github.com/rust-lang/rust/issues/74563 for more information",
1920 "fully-qualified syntax is unsupported"
1922 MalformedGenerics::InvalidPathSeparator => "has invalid path separator",
1923 MalformedGenerics::TooManyAngleBrackets => "too many angle brackets",
1924 MalformedGenerics::EmptyAngleBrackets => "empty angle brackets",
1926 if let Some(span) = sp {
1927 diag.span_label(span, note);
1935 /// Report an ambiguity error, where there were multiple possible resolutions.
1937 cx: &DocContext<'_>,
1938 diag_info: DiagnosticInfo<'_>,
1940 candidates: Vec<Res>,
1942 let mut msg = format!("`{}` is ", path_str);
1944 match candidates.as_slice() {
1945 [first_def, second_def] => {
1947 "both {} {} and {} {}",
1948 first_def.article(),
1950 second_def.article(),
1955 let mut candidates = candidates.iter().peekable();
1956 while let Some(res) = candidates.next() {
1957 if candidates.peek().is_some() {
1958 msg += &format!("{} {}, ", res.article(), res.descr());
1960 msg += &format!("and {} {}", res.article(), res.descr());
1966 report_diagnostic(cx.tcx, BROKEN_INTRA_DOC_LINKS, &msg, &diag_info, |diag, sp| {
1967 if let Some(sp) = sp {
1968 diag.span_label(sp, "ambiguous link");
1970 diag.note("ambiguous link");
1973 for res in candidates {
1974 suggest_disambiguator(res, diag, path_str, diag_info.ori_link, sp);
1979 /// In case of an ambiguity or mismatched disambiguator, suggest the correct
1981 fn suggest_disambiguator(
1983 diag: &mut Diagnostic,
1986 sp: Option<rustc_span::Span>,
1988 let suggestion = res.disambiguator_suggestion();
1989 let help = format!("to link to the {}, {}", res.descr(), suggestion.descr());
1991 if let Some(sp) = sp {
1992 let mut spans = suggestion.as_help_span(path_str, ori_link, sp);
1993 if spans.len() > 1 {
1994 diag.multipart_suggestion(&help, spans, Applicability::MaybeIncorrect);
1996 let (sp, suggestion_text) = spans.pop().unwrap();
1997 diag.span_suggestion_verbose(sp, &help, suggestion_text, Applicability::MaybeIncorrect);
2000 diag.help(&format!("{}: {}", help, suggestion.as_help(path_str)));
2004 /// Report a link from a public item to a private one.
2005 fn privacy_error(cx: &DocContext<'_>, diag_info: &DiagnosticInfo<'_>, path_str: &str) {
2007 let item_name = match diag_info.item.name {
2012 None => "<unknown>",
2015 format!("public documentation for `{}` links to private item `{}`", item_name, path_str);
2017 report_diagnostic(cx.tcx, PRIVATE_INTRA_DOC_LINKS, &msg, diag_info, |diag, sp| {
2018 if let Some(sp) = sp {
2019 diag.span_label(sp, "this item is private");
2022 let note_msg = if cx.render_options.document_private {
2023 "this link resolves only because you passed `--document-private-items`, but will break without"
2025 "this link will resolve properly if you pass `--document-private-items`"
2027 diag.note(note_msg);
2031 /// Resolve a primitive type or value.
2032 fn resolve_primitive(path_str: &str, ns: Namespace) -> Option<Res> {
2036 use PrimitiveType::*;
2037 let prim = match path_str {
2053 "bool" | "true" | "false" => Bool,
2054 "str" | "&str" => Str,
2055 // See #80181 for why these don't have symbols associated.
2060 "pointer" | "*const" | "*mut" => RawPointer,
2061 "reference" | "&" | "&mut" => Reference,
2063 "never" | "!" => Never,
2066 debug!("resolved primitives {:?}", prim);
2067 Some(Res::Primitive(prim))
2070 fn strip_generics_from_path(path_str: &str) -> Result<String, MalformedGenerics> {
2071 let mut stripped_segments = vec![];
2072 let mut path = path_str.chars().peekable();
2073 let mut segment = Vec::new();
2075 while let Some(chr) = path.next() {
2078 if path.next_if_eq(&':').is_some() {
2079 let stripped_segment =
2080 strip_generics_from_path_segment(mem::take(&mut segment))?;
2081 if !stripped_segment.is_empty() {
2082 stripped_segments.push(stripped_segment);
2085 return Err(MalformedGenerics::InvalidPathSeparator);
2093 return Err(MalformedGenerics::TooManyAngleBrackets);
2096 return Err(MalformedGenerics::EmptyAngleBrackets);
2101 while let Some(chr) = path.next_if(|c| *c != '>') {
2108 _ => segment.push(chr),
2110 trace!("raw segment: {:?}", segment);
2113 if !segment.is_empty() {
2114 let stripped_segment = strip_generics_from_path_segment(segment)?;
2115 if !stripped_segment.is_empty() {
2116 stripped_segments.push(stripped_segment);
2120 debug!("path_str: {:?}\nstripped segments: {:?}", path_str, &stripped_segments);
2122 let stripped_path = stripped_segments.join("::");
2124 if !stripped_path.is_empty() { Ok(stripped_path) } else { Err(MalformedGenerics::MissingType) }
2127 fn strip_generics_from_path_segment(segment: Vec<char>) -> Result<String, MalformedGenerics> {
2128 let mut stripped_segment = String::new();
2129 let mut param_depth = 0;
2131 let mut latest_generics_chunk = String::new();
2136 latest_generics_chunk.clear();
2137 } else if c == '>' {
2139 if latest_generics_chunk.contains(" as ") {
2140 // The segment tries to use fully-qualified syntax, which is currently unsupported.
2141 // Give a helpful error message instead of completely ignoring the angle brackets.
2142 return Err(MalformedGenerics::HasFullyQualifiedSyntax);
2145 if param_depth == 0 {
2146 stripped_segment.push(c);
2148 latest_generics_chunk.push(c);
2153 if param_depth == 0 {
2154 Ok(stripped_segment)
2156 // The segment has unbalanced angle brackets, e.g. `Vec<T` or `Vec<T>>`
2157 Err(MalformedGenerics::UnbalancedAngleBrackets)