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::{fx::FxHashMap, intern::Interned, stable_set::FxHashSet};
8 use rustc_errors::{Applicability, Diagnostic};
9 use rustc_hir::def::Namespace::*;
10 use rustc_hir::def::{DefKind, Namespace, PerNS};
11 use rustc_hir::def_id::{DefId, CRATE_DEF_ID};
12 use rustc_hir::Mutability;
13 use rustc_middle::ty::{DefIdTree, Ty, TyCtxt};
14 use rustc_middle::{bug, span_bug, ty};
15 use rustc_session::lint::Lint;
16 use rustc_span::hygiene::MacroKind;
17 use rustc_span::symbol::{sym, Ident, Symbol};
18 use rustc_span::{BytePos, DUMMY_SP};
19 use smallvec::{smallvec, SmallVec};
26 use crate::clean::{self, utils::find_nearest_parent_module};
27 use crate::clean::{Crate, Item, ItemId, ItemLink, PrimitiveType};
28 use crate::core::DocContext;
29 use crate::html::markdown::{markdown_links, MarkdownLink};
30 use crate::lint::{BROKEN_INTRA_DOC_LINKS, PRIVATE_INTRA_DOC_LINKS};
31 use crate::passes::Pass;
32 use crate::visit::DocVisitor;
35 crate use early::early_resolve_intra_doc_links;
37 crate const COLLECT_INTRA_DOC_LINKS: Pass = Pass {
38 name: "collect-intra-doc-links",
39 run: collect_intra_doc_links,
40 description: "resolves intra-doc links",
43 fn collect_intra_doc_links(krate: Crate, cx: &mut DocContext<'_>) -> Crate {
45 LinkCollector { cx, mod_ids: Vec::new(), visited_links: FxHashMap::default() };
46 collector.visit_crate(&krate);
50 /// Top-level errors emitted by this pass.
52 Resolve(Box<ResolutionFailure<'a>>),
53 AnchorFailure(AnchorFailure),
56 impl<'a> From<ResolutionFailure<'a>> for ErrorKind<'a> {
57 fn from(err: ResolutionFailure<'a>) -> Self {
58 ErrorKind::Resolve(box err)
62 #[derive(Copy, Clone, Debug, Hash)]
65 Primitive(PrimitiveType),
68 type ResolveRes = rustc_hir::def::Res<rustc_ast::NodeId>;
71 fn descr(self) -> &'static str {
73 Res::Def(kind, id) => ResolveRes::Def(kind, id).descr(),
74 Res::Primitive(_) => "builtin type",
78 fn article(self) -> &'static str {
80 Res::Def(kind, id) => ResolveRes::Def(kind, id).article(),
81 Res::Primitive(_) => "a",
85 fn name(self, tcx: TyCtxt<'_>) -> Symbol {
87 Res::Def(_, id) => tcx.item_name(id),
88 Res::Primitive(prim) => prim.as_sym(),
92 fn def_id(self, tcx: TyCtxt<'_>) -> DefId {
94 Res::Def(_, id) => id,
95 Res::Primitive(prim) => *PrimitiveType::primitive_locations(tcx).get(&prim).unwrap(),
99 fn as_hir_res(self) -> Option<rustc_hir::def::Res> {
101 Res::Def(kind, id) => Some(rustc_hir::def::Res::Def(kind, id)),
102 // FIXME: maybe this should handle the subset of PrimitiveType that fits into hir::PrimTy?
103 Res::Primitive(_) => None,
107 /// Used for error reporting.
108 fn disambiguator_suggestion(self) -> Suggestion {
109 let kind = match self {
110 Res::Primitive(_) => return Suggestion::Prefix("prim"),
111 Res::Def(kind, _) => kind,
113 if kind == DefKind::Macro(MacroKind::Bang) {
114 return Suggestion::Macro;
115 } else if kind == DefKind::Fn || kind == DefKind::AssocFn {
116 return Suggestion::Function;
117 } else if kind == DefKind::Field {
118 return Suggestion::RemoveDisambiguator;
121 let prefix = match kind {
122 DefKind::Struct => "struct",
123 DefKind::Enum => "enum",
124 DefKind::Trait => "trait",
125 DefKind::Union => "union",
126 DefKind::Mod => "mod",
127 DefKind::Const | DefKind::ConstParam | DefKind::AssocConst | DefKind::AnonConst => {
130 DefKind::Static(_) => "static",
131 DefKind::Macro(MacroKind::Derive) => "derive",
132 // Now handle things that don't have a specific disambiguator
135 .expect("tried to calculate a disambiguator for a def without a namespace?")
137 Namespace::TypeNS => "type",
138 Namespace::ValueNS => "value",
139 Namespace::MacroNS => "macro",
143 Suggestion::Prefix(prefix)
147 impl TryFrom<ResolveRes> for Res {
150 fn try_from(res: ResolveRes) -> Result<Self, ()> {
151 use rustc_hir::def::Res::*;
153 Def(kind, id) => Ok(Res::Def(kind, id)),
154 PrimTy(prim) => Ok(Res::Primitive(PrimitiveType::from_hir(prim))),
156 NonMacroAttr(..) | Err => Result::Err(()),
157 other => bug!("unrecognized res {:?}", other),
162 /// A link failed to resolve.
163 #[derive(Clone, Debug)]
164 enum ResolutionFailure<'a> {
165 /// This resolved, but with the wrong namespace.
167 /// What the link resolved to.
169 /// The expected namespace for the resolution, determined from the link's disambiguator.
171 /// E.g., for `[fn@Result]` this is [`Namespace::ValueNS`],
172 /// even though `Result`'s actual namespace is [`Namespace::TypeNS`].
173 expected_ns: Namespace,
175 /// The link failed to resolve. [`resolution_failure`] should look to see if there's
176 /// a more helpful error that can be given.
178 /// Item on which the link is resolved, used for resolving `Self`.
180 /// The scope the link was resolved in.
182 /// If part of the link resolved, this has the `Res`.
184 /// In `[std::io::Error::x]`, `std::io::Error` would be a partial resolution.
185 partial_res: Option<Res>,
186 /// The remaining unresolved path segments.
188 /// In `[std::io::Error::x]`, `x` would be unresolved.
189 unresolved: Cow<'a, str>,
191 /// This happens when rustdoc can't determine the parent scope for an item.
192 /// It is always a bug in rustdoc.
194 /// This link has malformed generic parameters; e.g., the angle brackets are unbalanced.
195 MalformedGenerics(MalformedGenerics),
196 /// Used to communicate that this should be ignored, but shouldn't be reported to the user.
198 /// This happens when there is no disambiguator and one of the namespaces
199 /// failed to resolve.
203 #[derive(Clone, Debug)]
204 enum MalformedGenerics {
205 /// This link has unbalanced angle brackets.
207 /// For example, `Vec<T` should trigger this, as should `Vec<T>>`.
208 UnbalancedAngleBrackets,
209 /// The generics are not attached to a type.
211 /// For example, `<T>` should trigger this.
213 /// This is detected by checking if the path is empty after the generics are stripped.
215 /// The link uses fully-qualified syntax, which is currently unsupported.
217 /// For example, `<Vec as IntoIterator>::into_iter` should trigger this.
219 /// This is detected by checking if ` as ` (the keyword `as` with spaces around it) is inside
221 HasFullyQualifiedSyntax,
222 /// The link has an invalid path separator.
224 /// For example, `Vec:<T>:new()` should trigger this. Note that `Vec:new()` will **not**
225 /// trigger this because it has no generics and thus [`strip_generics_from_path`] will not be
228 /// Note that this will also **not** be triggered if the invalid path separator is inside angle
229 /// brackets because rustdoc mostly ignores what's inside angle brackets (except for
230 /// [`HasFullyQualifiedSyntax`](MalformedGenerics::HasFullyQualifiedSyntax)).
232 /// This is detected by checking if there is a colon followed by a non-colon in the link.
233 InvalidPathSeparator,
234 /// The link has too many angle brackets.
236 /// For example, `Vec<<T>>` should trigger this.
237 TooManyAngleBrackets,
238 /// The link has empty angle brackets.
240 /// For example, `Vec<>` should trigger this.
244 impl ResolutionFailure<'_> {
245 /// This resolved fully (not just partially) but is erroneous for some other reason
247 /// Returns the full resolution of the link, if present.
248 fn full_res(&self) -> Option<Res> {
250 Self::WrongNamespace { res, expected_ns: _ } => Some(*res),
256 #[derive(Clone, Copy)]
258 /// User error: `[std#x#y]` is not valid
260 /// The anchor provided by the user conflicts with Rustdoc's generated anchor.
262 /// This is an unfortunate state of affairs. Not every item that can be
263 /// linked to has its own page; sometimes it is a subheading within a page,
264 /// like for associated items. In those cases, rustdoc uses an anchor to
265 /// link to the subheading. Since you can't have two anchors for the same
266 /// link, Rustdoc disallows having a user-specified anchor.
268 /// Most of the time this is fine, because you can just link to the page of
269 /// the item if you want to provide your own anchor.
270 RustdocAnchorConflict(Res),
273 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
274 crate enum UrlFragment {
280 /// Render the fragment, including the leading `#`.
281 crate fn render(&self, s: &mut String, tcx: TyCtxt<'_>) -> std::fmt::Result {
283 UrlFragment::Item(frag) => frag.render(s, tcx),
284 UrlFragment::UserWritten(raw) => write!(s, "#{}", raw),
289 #[derive(Copy, Clone, Debug, Hash, PartialEq, Eq)]
290 crate struct ItemFragment(FragmentKind, DefId);
292 #[derive(Copy, Clone, Debug, Hash, PartialEq, Eq)]
293 crate enum FragmentKind {
305 /// Create a fragment for an associated item.
306 #[instrument(level = "debug")]
307 fn from_assoc_item(item: &ty::AssocItem) -> Self {
308 let def_id = item.def_id;
310 ty::AssocKind::Fn => {
311 if item.defaultness.has_value() {
312 ItemFragment(FragmentKind::Method, def_id)
314 ItemFragment(FragmentKind::TyMethod, def_id)
317 ty::AssocKind::Const => ItemFragment(FragmentKind::AssociatedConstant, def_id),
318 ty::AssocKind::Type => ItemFragment(FragmentKind::AssociatedType, def_id),
322 /// Render the fragment, including the leading `#`.
323 crate fn render(&self, s: &mut String, tcx: TyCtxt<'_>) -> std::fmt::Result {
326 ItemFragment(kind, def_id) => {
327 let name = tcx.item_name(def_id);
329 FragmentKind::Method => write!(s, "method.{}", name),
330 FragmentKind::TyMethod => write!(s, "tymethod.{}", name),
331 FragmentKind::AssociatedConstant => write!(s, "associatedconstant.{}", name),
332 FragmentKind::AssociatedType => write!(s, "associatedtype.{}", name),
333 FragmentKind::StructField => write!(s, "structfield.{}", name),
334 FragmentKind::Variant => write!(s, "variant.{}", name),
335 FragmentKind::VariantField => {
336 let variant = tcx.item_name(tcx.parent(def_id).unwrap());
337 write!(s, "variant.{}.field.{}", variant, name)
345 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
346 struct ResolutionInfo {
349 dis: Option<Disambiguator>,
351 extra_fragment: Option<String>,
355 struct DiagnosticInfo<'a> {
359 link_range: Range<usize>,
362 #[derive(Clone, Debug, Hash)]
364 res: (Res, Option<UrlFragment>),
367 struct LinkCollector<'a, 'tcx> {
368 cx: &'a mut DocContext<'tcx>,
369 /// A stack of modules used to decide what scope to resolve in.
371 /// The last module will be used if the parent scope of the current item is
374 /// Cache the resolved links so we can avoid resolving (and emitting errors for) the same link.
375 /// The link will be `None` if it could not be resolved (i.e. the error was cached).
376 visited_links: FxHashMap<ResolutionInfo, Option<CachedLink>>,
379 impl<'a, 'tcx> LinkCollector<'a, 'tcx> {
380 /// Given a full link, parse it as an [enum struct variant].
382 /// In particular, this will return an error whenever there aren't three
383 /// full path segments left in the link.
385 /// [enum struct variant]: rustc_hir::VariantData::Struct
386 fn variant_field<'path>(
388 path_str: &'path str,
391 ) -> Result<(Res, Option<ItemFragment>), ErrorKind<'path>> {
392 let tcx = self.cx.tcx;
393 let no_res = || ResolutionFailure::NotResolved {
397 unresolved: path_str.into(),
400 debug!("looking for enum variant {}", path_str);
401 let mut split = path_str.rsplitn(3, "::");
402 let variant_field_name = split
404 .map(|f| Symbol::intern(f))
405 .expect("fold_item should ensure link is non-empty");
407 // we're not sure this is a variant at all, so use the full string
408 // If there's no second component, the link looks like `[path]`.
409 // So there's no partial res and we should say the whole link failed to resolve.
410 split.next().map(|f| Symbol::intern(f)).ok_or_else(no_res)?;
413 .map(|f| f.to_owned())
414 // If there's no third component, we saw `[a::b]` before and it failed to resolve.
415 // So there's no partial res.
416 .ok_or_else(no_res)?;
417 let ty_res = self.resolve_path(&path, TypeNS, item_id, module_id).ok_or_else(no_res)?;
420 Res::Def(DefKind::Enum, did) => {
424 .flat_map(|imp| tcx.associated_items(*imp).in_definition_order())
425 .any(|item| item.name == variant_name)
427 // This is just to let `fold_item` know that this shouldn't be considered;
428 // it's a bug for the error to make it to the user
429 return Err(ResolutionFailure::Dummy.into());
431 match tcx.type_of(did).kind() {
432 ty::Adt(def, _) if def.is_enum() => {
433 if let Some(field) = def.all_fields().find(|f| f.name == variant_field_name)
435 Ok((ty_res, Some(ItemFragment(FragmentKind::VariantField, field.did))))
437 Err(ResolutionFailure::NotResolved {
440 partial_res: Some(Res::Def(DefKind::Enum, def.did())),
441 unresolved: variant_field_name.to_string().into(),
449 _ => Err(ResolutionFailure::NotResolved {
452 partial_res: Some(ty_res),
453 unresolved: variant_name.to_string().into(),
459 /// Given a primitive type, try to resolve an associated item.
460 fn resolve_primitive_associated_item(
462 prim_ty: PrimitiveType,
465 ) -> Option<(Res, ItemFragment)> {
466 let tcx = self.cx.tcx;
468 prim_ty.impls(tcx).find_map(|impl_| {
469 tcx.associated_items(impl_)
470 .find_by_name_and_namespace(tcx, Ident::with_dummy_span(item_name), ns, impl_)
472 let fragment = ItemFragment::from_assoc_item(item);
473 (Res::Primitive(prim_ty), fragment)
478 /// Resolves a string as a macro.
480 /// FIXME(jynelson): Can this be unified with `resolve()`?
486 ) -> Result<Res, ResolutionFailure<'a>> {
487 self.resolve_path(path_str, MacroNS, item_id, module_id).ok_or_else(|| {
488 ResolutionFailure::NotResolved {
492 unresolved: path_str.into(),
497 fn resolve_self_ty(&self, path_str: &str, ns: Namespace, item_id: ItemId) -> Option<Res> {
498 if ns != TypeNS || path_str != "Self" {
502 let tcx = self.cx.tcx;
505 .map(|def_id| match tcx.def_kind(def_id) {
506 def_kind @ (DefKind::AssocFn
507 | DefKind::AssocConst
510 | DefKind::Field) => {
511 let parent_def_id = tcx.parent(def_id).expect("nested item has no parent");
512 if def_kind == DefKind::Field && tcx.def_kind(parent_def_id) == DefKind::Variant
514 tcx.parent(parent_def_id).expect("variant has no parent")
521 .and_then(|self_id| match tcx.def_kind(self_id) {
522 DefKind::Impl => self.def_id_to_res(self_id),
523 def_kind => Some(Res::Def(def_kind, self_id)),
527 /// HACK: Try to search the macro name in the list of all `macro_rules` items in the crate.
528 /// Used when nothing else works, may often give an incorrect result.
529 fn resolve_macro_rules(&self, path_str: &str, ns: Namespace) -> Option<Res> {
537 .get(&Symbol::intern(path_str))
539 .and_then(|res| res.try_into().ok())
542 /// Convenience wrapper around `resolve_rustdoc_path`.
544 /// This also handles resolving `true` and `false` as booleans.
545 /// NOTE: `resolve_rustdoc_path` knows only about paths, not about types.
546 /// Associated items will never be resolved by this function.
554 if let res @ Some(..) = self.resolve_self_ty(path_str, ns, item_id) {
558 // Resolver doesn't know about true, false, and types that aren't paths (e.g. `()`).
562 .doc_link_resolutions
563 .get(&(Symbol::intern(path_str), ns, module_id))
566 self.cx.enter_resolver(|resolver| {
567 resolver.resolve_rustdoc_path(path_str, ns, module_id)
570 .and_then(|res| res.try_into().ok())
571 .or_else(|| resolve_primitive(path_str, ns))
572 .or_else(|| self.resolve_macro_rules(path_str, ns));
573 debug!("{} resolved to {:?} in namespace {:?}", path_str, result, ns);
577 /// Resolves a string as a path within a particular namespace. Returns an
578 /// optional URL fragment in the case of variants and methods.
581 path_str: &'path str,
585 user_fragment: &Option<String>,
586 ) -> Result<(Res, Option<UrlFragment>), ErrorKind<'path>> {
587 let (res, rustdoc_fragment) = self.resolve_inner(path_str, ns, item_id, module_id)?;
588 let chosen_fragment = match (user_fragment, rustdoc_fragment) {
589 (Some(_), Some(r_frag)) => {
590 let diag_res = match r_frag {
591 ItemFragment(_, did) => Res::Def(self.cx.tcx.def_kind(did), did),
593 let failure = AnchorFailure::RustdocAnchorConflict(diag_res);
594 return Err(ErrorKind::AnchorFailure(failure));
596 (Some(u_frag), None) => Some(UrlFragment::UserWritten(u_frag.clone())),
597 (None, Some(r_frag)) => Some(UrlFragment::Item(r_frag)),
598 (None, None) => None,
600 Ok((res, chosen_fragment))
603 fn resolve_inner<'path>(
605 path_str: &'path str,
609 ) -> Result<(Res, Option<ItemFragment>), ErrorKind<'path>> {
610 if let Some(res) = self.resolve_path(path_str, ns, item_id, module_id) {
612 // FIXME(#76467): make this fallthrough to lookup the associated
613 // item a separate function.
614 Res::Def(DefKind::AssocFn | DefKind::AssocConst, _) => assert_eq!(ns, ValueNS),
615 Res::Def(DefKind::AssocTy, _) => assert_eq!(ns, TypeNS),
616 Res::Def(DefKind::Variant, _) => {
617 return handle_variant(self.cx, res);
619 // Not a trait item; just return what we found.
620 _ => return Ok((res, None)),
624 // Try looking for methods and associated items.
625 let mut split = path_str.rsplitn(2, "::");
626 // NB: `split`'s first element is always defined, even if the delimiter was not present.
627 // NB: `item_str` could be empty when resolving in the root namespace (e.g. `::std`).
628 let item_str = split.next().unwrap();
629 let item_name = Symbol::intern(item_str);
630 let path_root = split
632 .map(|f| f.to_owned())
633 // If there's no `::`, it's not an associated item.
634 // So we can be sure that `rustc_resolve` was accurate when it said it wasn't resolved.
636 debug!("found no `::`, assumming {} was correctly not in scope", item_name);
637 ResolutionFailure::NotResolved {
641 unresolved: item_str.into(),
645 // FIXME(#83862): this arbitrarily gives precedence to primitives over modules to support
646 // links to primitives when `#[doc(primitive)]` is present. It should give an ambiguity
647 // error instead and special case *only* modules with `#[doc(primitive)]`, not all
649 resolve_primitive(&path_root, TypeNS)
650 .or_else(|| self.resolve_path(&path_root, TypeNS, item_id, module_id))
652 let (res, fragment) =
653 self.resolve_associated_item(ty_res, item_name, ns, module_id)?;
655 Some(Ok((res, Some(fragment))))
658 if ns == Namespace::ValueNS {
659 self.variant_field(path_str, item_id, module_id)
661 Err(ResolutionFailure::NotResolved {
665 unresolved: path_root.into(),
672 /// Convert a DefId to a Res, where possible.
674 /// This is used for resolving type aliases.
675 fn def_id_to_res(&self, ty_id: DefId) -> Option<Res> {
676 use PrimitiveType::*;
677 Some(match *self.cx.tcx.type_of(ty_id).kind() {
678 ty::Bool => Res::Primitive(Bool),
679 ty::Char => Res::Primitive(Char),
680 ty::Int(ity) => Res::Primitive(ity.into()),
681 ty::Uint(uty) => Res::Primitive(uty.into()),
682 ty::Float(fty) => Res::Primitive(fty.into()),
683 ty::Str => Res::Primitive(Str),
684 ty::Tuple(tys) if tys.is_empty() => Res::Primitive(Unit),
685 ty::Tuple(_) => Res::Primitive(Tuple),
686 ty::Array(..) => Res::Primitive(Array),
687 ty::Slice(_) => Res::Primitive(Slice),
688 ty::RawPtr(_) => Res::Primitive(RawPointer),
689 ty::Ref(..) => Res::Primitive(Reference),
690 ty::FnDef(..) => panic!("type alias to a function definition"),
691 ty::FnPtr(_) => Res::Primitive(Fn),
692 ty::Never => Res::Primitive(Never),
693 ty::Adt(ty::AdtDef(Interned(&ty::AdtDefData { did, .. }, _)), _) | ty::Foreign(did) => {
694 Res::Def(self.cx.tcx.def_kind(did), did)
699 | ty::GeneratorWitness(_)
706 | ty::Error(_) => return None,
710 /// Convert a PrimitiveType to a Ty, where possible.
712 /// This is used for resolving trait impls for primitives
713 fn primitive_type_to_ty(&mut self, prim: PrimitiveType) -> Option<Ty<'tcx>> {
714 use PrimitiveType::*;
715 let tcx = self.cx.tcx;
717 // FIXME: Only simple types are supported here, see if we can support
718 // other types such as Tuple, Array, Slice, etc.
719 // See https://github.com/rust-lang/rust/issues/90703#issuecomment-1004263455
720 Some(tcx.mk_ty(match prim {
725 I8 => ty::Int(ty::IntTy::I8),
726 I16 => ty::Int(ty::IntTy::I16),
727 I32 => ty::Int(ty::IntTy::I32),
728 I64 => ty::Int(ty::IntTy::I64),
729 I128 => ty::Int(ty::IntTy::I128),
730 Isize => ty::Int(ty::IntTy::Isize),
731 F32 => ty::Float(ty::FloatTy::F32),
732 F64 => ty::Float(ty::FloatTy::F64),
733 U8 => ty::Uint(ty::UintTy::U8),
734 U16 => ty::Uint(ty::UintTy::U16),
735 U32 => ty::Uint(ty::UintTy::U32),
736 U64 => ty::Uint(ty::UintTy::U64),
737 U128 => ty::Uint(ty::UintTy::U128),
738 Usize => ty::Uint(ty::UintTy::Usize),
743 /// Resolve an associated item, returning its containing page's `Res`
744 /// and the fragment targeting the associated item on its page.
745 fn resolve_associated_item(
751 ) -> Option<(Res, ItemFragment)> {
752 let tcx = self.cx.tcx;
755 Res::Primitive(prim) => {
756 self.resolve_primitive_associated_item(prim, ns, item_name).or_else(|| {
757 let assoc_item = self
758 .primitive_type_to_ty(prim)
760 resolve_associated_trait_item(ty, module_id, item_name, ns, self.cx)
764 assoc_item.map(|item| {
765 let fragment = ItemFragment::from_assoc_item(&item);
770 Res::Def(DefKind::TyAlias, did) => {
771 // Resolve the link on the type the alias points to.
772 // FIXME: if the associated item is defined directly on the type alias,
773 // it will show up on its documentation page, we should link there instead.
774 let res = self.def_id_to_res(did)?;
775 self.resolve_associated_item(res, item_name, ns, module_id)
778 def_kind @ (DefKind::Struct | DefKind::Union | DefKind::Enum | DefKind::ForeignTy),
781 debug!("looking for associated item named {} for item {:?}", item_name, did);
782 // Checks if item_name is a variant of the `SomeItem` enum
783 if ns == TypeNS && def_kind == DefKind::Enum {
784 match tcx.type_of(did).kind() {
785 ty::Adt(adt_def, _) => {
786 for variant in adt_def.variants() {
787 if variant.name == item_name {
790 ItemFragment(FragmentKind::Variant, variant.def_id),
799 // Checks if item_name belongs to `impl SomeItem`
804 tcx.associated_items(imp).find_by_name_and_namespace(
806 Ident::with_dummy_span(item_name),
812 // There should only ever be one associated item that matches from any inherent impl
814 // Check if item_name belongs to `impl SomeTrait for SomeItem`
815 // FIXME(#74563): This gives precedence to `impl SomeItem`:
816 // Although having both would be ambiguous, use impl version for compatibility's sake.
817 // To handle that properly resolve() would have to support
818 // something like [`ambi_fn`](<SomeStruct as SomeTrait>::ambi_fn)
820 resolve_associated_trait_item(
829 debug!("got associated item {:?}", assoc_item);
831 if let Some(item) = assoc_item {
832 let fragment = ItemFragment::from_assoc_item(&item);
833 return Some((root_res, fragment));
836 if ns != Namespace::ValueNS {
839 debug!("looking for fields named {} for {:?}", item_name, did);
840 // FIXME: this doesn't really belong in `associated_item` (maybe `variant_field` is better?)
841 // NOTE: it's different from variant_field because it only resolves struct fields,
842 // not variant fields (2 path segments, not 3).
844 // We need to handle struct (and union) fields in this code because
845 // syntactically their paths are identical to associated item paths:
846 // `module::Type::field` and `module::Type::Assoc`.
848 // On the other hand, variant fields can't be mistaken for associated
849 // items because they look like this: `module::Type::Variant::field`.
851 // Variants themselves don't need to be handled here, even though
852 // they also look like associated items (`module::Type::Variant`),
853 // because they are real Rust syntax (unlike the intra-doc links
854 // field syntax) and are handled by the compiler's resolver.
855 let def = match tcx.type_of(did).kind() {
856 ty::Adt(def, _) if !def.is_enum() => def,
860 def.non_enum_variant().fields.iter().find(|item| item.name == item_name)?;
861 Some((root_res, ItemFragment(FragmentKind::StructField, field.did)))
863 Res::Def(DefKind::Trait, did) => tcx
864 .associated_items(did)
865 .find_by_name_and_namespace(tcx, Ident::with_dummy_span(item_name), ns, did)
867 let fragment = ItemFragment::from_assoc_item(item);
868 let res = Res::Def(item.kind.as_def_kind(), item.def_id);
875 /// Used for reporting better errors.
877 /// Returns whether the link resolved 'fully' in another namespace.
878 /// 'fully' here means that all parts of the link resolved, not just some path segments.
879 /// This returns the `Res` even if it was erroneous for some reason
880 /// (such as having invalid URL fragments or being in the wrong namespace).
887 extra_fragment: &Option<String>,
889 // resolve() can't be used for macro namespace
890 let result = match ns {
891 Namespace::MacroNS => self
892 .resolve_macro(path_str, item_id, module_id)
893 .map(|res| (res, None))
894 .map_err(ErrorKind::from),
895 Namespace::TypeNS | Namespace::ValueNS => {
896 self.resolve(path_str, ns, item_id, module_id, extra_fragment)
900 let res = match result {
902 if let Some(UrlFragment::Item(ItemFragment(_, id))) = frag {
903 Some(Res::Def(self.cx.tcx.def_kind(id), id))
908 Err(ErrorKind::Resolve(box kind)) => kind.full_res(),
909 Err(ErrorKind::AnchorFailure(AnchorFailure::RustdocAnchorConflict(res))) => Some(res),
910 Err(ErrorKind::AnchorFailure(AnchorFailure::MultipleAnchors)) => None,
916 /// Look to see if a resolved item has an associated item named `item_name`.
918 /// Given `[std::io::Error::source]`, where `source` is unresolved, this would
919 /// find `std::error::Error::source` and return
920 /// `<io::Error as error::Error>::source`.
921 fn resolve_associated_trait_item<'a>(
926 cx: &mut DocContext<'a>,
927 ) -> Option<ty::AssocItem> {
928 // FIXME: this should also consider blanket impls (`impl<T> X for T`). Unfortunately
929 // `get_auto_trait_and_blanket_impls` is broken because the caching behavior is wrong. In the
930 // meantime, just don't look for these blanket impls.
932 // Next consider explicit impls: `impl MyTrait for MyType`
933 // Give precedence to inherent impls.
934 let traits = trait_impls_for(cx, ty, module);
935 debug!("considering traits {:?}", traits);
936 let mut candidates = traits.iter().filter_map(|&(impl_, trait_)| {
938 .associated_items(trait_)
939 .find_by_name_and_namespace(cx.tcx, Ident::with_dummy_span(item_name), ns, trait_)
941 trait_assoc_to_impl_assoc_item(cx.tcx, impl_, trait_assoc.def_id)
942 .unwrap_or(trait_assoc)
945 // FIXME(#74563): warn about ambiguity
946 debug!("the candidates were {:?}", candidates.clone().collect::<Vec<_>>());
947 candidates.next().copied()
950 /// Find the associated item in the impl `impl_id` that corresponds to the
951 /// trait associated item `trait_assoc_id`.
953 /// This function returns `None` if no associated item was found in the impl.
954 /// This can occur when the trait associated item has a default value that is
955 /// not overridden in the impl.
957 /// This is just a wrapper around [`TyCtxt::impl_item_implementor_ids()`] and
958 /// [`TyCtxt::associated_item()`] (with some helpful logging added).
959 #[instrument(level = "debug", skip(tcx))]
960 fn trait_assoc_to_impl_assoc_item<'tcx>(
963 trait_assoc_id: DefId,
964 ) -> Option<&'tcx ty::AssocItem> {
965 let trait_to_impl_assoc_map = tcx.impl_item_implementor_ids(impl_id);
966 debug!(?trait_to_impl_assoc_map);
967 let impl_assoc_id = *trait_to_impl_assoc_map.get(&trait_assoc_id)?;
968 debug!(?impl_assoc_id);
969 let impl_assoc = tcx.associated_item(impl_assoc_id);
974 /// Given a type, return all trait impls in scope in `module` for that type.
975 /// Returns a set of pairs of `(impl_id, trait_id)`.
977 /// NOTE: this cannot be a query because more traits could be available when more crates are compiled!
978 /// So it is not stable to serialize cross-crate.
979 #[instrument(level = "debug", skip(cx))]
980 fn trait_impls_for<'a>(
981 cx: &mut DocContext<'a>,
984 ) -> FxHashSet<(DefId, DefId)> {
986 let iter = cx.resolver_caches.traits_in_scope[&module].iter().flat_map(|trait_candidate| {
987 let trait_ = trait_candidate.def_id;
988 trace!("considering explicit impl for trait {:?}", trait_);
990 // Look at each trait implementation to see if it's an impl for `did`
991 tcx.find_map_relevant_impl(trait_, ty, |impl_| {
992 let trait_ref = tcx.impl_trait_ref(impl_).expect("this is not an inherent impl");
993 // Check if these are the same type.
994 let impl_type = trait_ref.self_ty();
996 "comparing type {} with kind {:?} against type {:?}",
1001 // Fast path: if this is a primitive simple `==` will work
1002 // NOTE: the `match` is necessary; see #92662.
1003 // this allows us to ignore generics because the user input
1004 // may not include the generic placeholders
1005 // e.g. this allows us to match Foo (user comment) with Foo<T> (actual type)
1006 let saw_impl = impl_type == ty
1007 || match (impl_type.kind(), ty.kind()) {
1008 (ty::Adt(impl_def, _), ty::Adt(ty_def, _)) => {
1009 debug!("impl def_id: {:?}, ty def_id: {:?}", impl_def.did(), ty_def.did());
1010 impl_def.did() == ty_def.did()
1015 if saw_impl { Some((impl_, trait_)) } else { None }
1021 /// Check for resolve collisions between a trait and its derive.
1023 /// These are common and we should just resolve to the trait in that case.
1024 fn is_derive_trait_collision<T>(ns: &PerNS<Result<(Res, T), ResolutionFailure<'_>>>) -> bool {
1028 type_ns: Ok((Res::Def(DefKind::Trait, _), _)),
1029 macro_ns: Ok((Res::Def(DefKind::Macro(MacroKind::Derive), _), _)),
1035 impl<'a, 'tcx> DocVisitor for LinkCollector<'a, 'tcx> {
1036 fn visit_item(&mut self, item: &Item) {
1038 item.item_id.as_def_id().and_then(|did| find_nearest_parent_module(self.cx.tcx, did));
1039 if parent_node.is_some() {
1040 trace!("got parent node for {:?} {:?}, id {:?}", item.type_(), item.name, item.item_id);
1043 let inner_docs = item.inner_docs(self.cx.tcx);
1045 if item.is_mod() && inner_docs {
1046 self.mod_ids.push(item.item_id.expect_def_id());
1049 // We want to resolve in the lexical scope of the documentation.
1050 // In the presence of re-exports, this is not the same as the module of the item.
1051 // Rather than merging all documentation into one, resolve it one attribute at a time
1052 // so we know which module it came from.
1053 for (parent_module, doc) in item.attrs.prepare_to_doc_link_resolution() {
1054 if !may_have_doc_links(&doc) {
1057 debug!("combined_docs={}", doc);
1058 // NOTE: if there are links that start in one crate and end in another, this will not resolve them.
1059 // This is a degenerate case and it's not supported by rustdoc.
1060 let parent_node = parent_module.or(parent_node);
1061 let mut tmp_links = self
1066 .expect("`markdown_links` are already borrowed");
1067 if !tmp_links.contains_key(&doc) {
1068 tmp_links.insert(doc.clone(), preprocessed_markdown_links(&doc));
1070 for md_link in &tmp_links[&doc] {
1071 let link = self.resolve_link(&item, &doc, parent_node, md_link);
1072 if let Some(link) = link {
1073 self.cx.cache.intra_doc_links.entry(item.item_id).or_default().push(link);
1076 self.cx.resolver_caches.markdown_links = Some(tmp_links);
1081 self.mod_ids.push(item.item_id.expect_def_id());
1084 self.visit_item_recur(item);
1087 self.visit_item_recur(item)
1092 enum PreprocessingError {
1093 Anchor(AnchorFailure),
1094 Disambiguator(Range<usize>, String),
1095 Resolution(ResolutionFailure<'static>, String, Option<Disambiguator>),
1098 impl From<AnchorFailure> for PreprocessingError {
1099 fn from(err: AnchorFailure) -> Self {
1105 struct PreprocessingInfo {
1107 disambiguator: Option<Disambiguator>,
1108 extra_fragment: Option<String>,
1112 // Not a typedef to avoid leaking several private structures from this module.
1113 crate struct PreprocessedMarkdownLink(Result<PreprocessingInfo, PreprocessingError>, MarkdownLink);
1116 /// - `None` if the link should be ignored.
1117 /// - `Some(Err)` if the link should emit an error
1118 /// - `Some(Ok)` if the link is valid
1120 /// `link_buffer` is needed for lifetime reasons; it will always be overwritten and the contents ignored.
1122 ori_link: &MarkdownLink,
1123 ) -> Option<Result<PreprocessingInfo, PreprocessingError>> {
1124 // [] is mostly likely not supposed to be a link
1125 if ori_link.link.is_empty() {
1129 // Bail early for real links.
1130 if ori_link.link.contains('/') {
1134 let stripped = ori_link.link.replace('`', "");
1135 let mut parts = stripped.split('#');
1137 let link = parts.next().unwrap();
1138 if link.trim().is_empty() {
1139 // This is an anchor to an element of the current page, nothing to do in here!
1142 let extra_fragment = parts.next();
1143 if parts.next().is_some() {
1144 // A valid link can't have multiple #'s
1145 return Some(Err(AnchorFailure::MultipleAnchors.into()));
1148 // Parse and strip the disambiguator from the link, if present.
1149 let (disambiguator, path_str, link_text) = match Disambiguator::from_str(link) {
1150 Ok(Some((d, path, link_text))) => (Some(d), path.trim(), link_text.trim()),
1151 Ok(None) => (None, link.trim(), link.trim()),
1152 Err((err_msg, relative_range)) => {
1153 // Only report error if we would not have ignored this link. See issue #83859.
1154 if !should_ignore_link_with_disambiguators(link) {
1155 let no_backticks_range = range_between_backticks(ori_link);
1156 let disambiguator_range = (no_backticks_range.start + relative_range.start)
1157 ..(no_backticks_range.start + relative_range.end);
1158 return Some(Err(PreprocessingError::Disambiguator(disambiguator_range, err_msg)));
1165 if should_ignore_link(path_str) {
1169 // Strip generics from the path.
1170 let path_str = if path_str.contains(['<', '>'].as_slice()) {
1171 match strip_generics_from_path(path_str) {
1174 debug!("link has malformed generics: {}", path_str);
1175 return Some(Err(PreprocessingError::Resolution(
1177 path_str.to_owned(),
1186 // Sanity check to make sure we don't have any angle brackets after stripping generics.
1187 assert!(!path_str.contains(['<', '>'].as_slice()));
1189 // The link is not an intra-doc link if it still contains spaces after stripping generics.
1190 if path_str.contains(' ') {
1194 Some(Ok(PreprocessingInfo {
1197 extra_fragment: extra_fragment.map(|frag| frag.to_owned()),
1198 link_text: link_text.to_owned(),
1202 fn preprocessed_markdown_links(s: &str) -> Vec<PreprocessedMarkdownLink> {
1203 markdown_links(s, |link| {
1204 preprocess_link(&link).map(|pp_link| PreprocessedMarkdownLink(pp_link, link))
1208 impl LinkCollector<'_, '_> {
1209 /// This is the entry point for resolving an intra-doc link.
1211 /// FIXME(jynelson): this is way too many arguments
1216 parent_node: Option<DefId>,
1217 link: &PreprocessedMarkdownLink,
1218 ) -> Option<ItemLink> {
1219 let PreprocessedMarkdownLink(pp_link, ori_link) = link;
1220 trace!("considering link '{}'", ori_link.link);
1222 let diag_info = DiagnosticInfo {
1225 ori_link: &ori_link.link,
1226 link_range: ori_link.range.clone(),
1229 let PreprocessingInfo { path_str, disambiguator, extra_fragment, link_text } = match pp_link
1234 PreprocessingError::Anchor(err) => anchor_failure(self.cx, diag_info, *err),
1235 PreprocessingError::Disambiguator(range, msg) => {
1236 disambiguator_error(self.cx, diag_info, range.clone(), msg)
1238 PreprocessingError::Resolution(err, path_str, disambiguator) => {
1244 smallvec![err.clone()],
1251 let disambiguator = *disambiguator;
1253 let inner_docs = item.inner_docs(self.cx.tcx);
1255 // In order to correctly resolve intra-doc links we need to
1256 // pick a base AST node to work from. If the documentation for
1257 // this module came from an inner comment (//!) then we anchor
1258 // our name resolution *inside* the module. If, on the other
1259 // hand it was an outer comment (///) then we anchor the name
1260 // resolution in the parent module on the basis that the names
1261 // used are more likely to be intended to be parent names. For
1262 // this, we set base_node to None for inner comments since
1263 // we've already pushed this node onto the resolution stack but
1264 // for outer comments we explicitly try and resolve against the
1265 // parent_node first.
1267 if item.is_mod() && inner_docs { self.mod_ids.last().copied() } else { parent_node };
1269 let Some(module_id) = base_node else {
1271 debug!("attempting to resolve item without parent module: {}", path_str);
1277 smallvec![ResolutionFailure::NoParentItem],
1282 let (mut res, fragment) = self.resolve_with_disambiguator_cached(
1284 item_id: item.item_id,
1287 path_str: path_str.to_owned(),
1288 extra_fragment: extra_fragment.clone(),
1290 diag_info.clone(), // this struct should really be Copy, but Range is not :(
1291 matches!(ori_link.kind, LinkType::Reference | LinkType::Shortcut),
1294 // Check for a primitive which might conflict with a module
1295 // Report the ambiguity and require that the user specify which one they meant.
1296 // FIXME: could there ever be a primitive not in the type namespace?
1299 None | Some(Disambiguator::Namespace(Namespace::TypeNS) | Disambiguator::Primitive)
1300 ) && !matches!(res, Res::Primitive(_))
1302 if let Some(prim) = resolve_primitive(path_str, TypeNS) {
1304 if matches!(disambiguator, Some(Disambiguator::Primitive)) {
1307 // `[char]` when a `char` module is in scope
1308 let candidates = vec![res, prim];
1309 ambiguity_error(self.cx, diag_info, path_str, candidates);
1316 Res::Primitive(prim) => {
1317 if let Some(UrlFragment::Item(ItemFragment(_, id))) = fragment {
1318 // We're actually resolving an associated item of a primitive, so we need to
1319 // verify the disambiguator (if any) matches the type of the associated item.
1320 // This case should really follow the same flow as the `Res::Def` branch below,
1321 // but attempting to add a call to `clean::register_res` causes an ICE. @jyn514
1322 // thinks `register_res` is only needed for cross-crate re-exports, but Rust
1323 // doesn't allow statements like `use str::trim;`, making this a (hopefully)
1324 // valid omission. See https://github.com/rust-lang/rust/pull/80660#discussion_r551585677
1325 // for discussion on the matter.
1326 let kind = self.cx.tcx.def_kind(id);
1327 self.verify_disambiguator(
1337 // FIXME: it would be nice to check that the feature gate was enabled in the original crate, not just ignore it altogether.
1338 // However I'm not sure how to check that across crates.
1339 if prim == PrimitiveType::RawPointer
1340 && item.item_id.is_local()
1341 && !self.cx.tcx.features().intra_doc_pointers
1343 self.report_rawptr_assoc_feature_gate(dox, &ori_link, item);
1346 match disambiguator {
1347 Some(Disambiguator::Primitive | Disambiguator::Namespace(_)) | None => {}
1349 self.report_disambiguator_mismatch(
1350 path_str, &ori_link, other, res, &diag_info,
1358 link: ori_link.link.clone(),
1359 link_text: link_text.clone(),
1360 did: res.def_id(self.cx.tcx),
1364 Res::Def(kind, id) => {
1365 let (kind_for_dis, id_for_dis) =
1366 if let Some(UrlFragment::Item(ItemFragment(_, id))) = fragment {
1367 (self.cx.tcx.def_kind(id), id)
1371 self.verify_disambiguator(
1380 let id = clean::register_res(self.cx, rustc_hir::def::Res::Def(kind, id));
1382 link: ori_link.link.clone(),
1383 link_text: link_text.clone(),
1391 fn verify_disambiguator(
1394 ori_link: &MarkdownLink,
1397 disambiguator: Option<Disambiguator>,
1399 diag_info: &DiagnosticInfo<'_>,
1401 debug!("intra-doc link to {} resolved to {:?}", path_str, (kind, id));
1403 // Disallow e.g. linking to enums with `struct@`
1404 debug!("saw kind {:?} with disambiguator {:?}", kind, disambiguator);
1405 match (kind, disambiguator) {
1406 | (DefKind::Const | DefKind::ConstParam | DefKind::AssocConst | DefKind::AnonConst, Some(Disambiguator::Kind(DefKind::Const)))
1407 // NOTE: this allows 'method' to mean both normal functions and associated functions
1408 // This can't cause ambiguity because both are in the same namespace.
1409 | (DefKind::Fn | DefKind::AssocFn, Some(Disambiguator::Kind(DefKind::Fn)))
1410 // These are namespaces; allow anything in the namespace to match
1411 | (_, Some(Disambiguator::Namespace(_)))
1412 // If no disambiguator given, allow anything
1414 // All of these are valid, so do nothing
1416 (actual, Some(Disambiguator::Kind(expected))) if actual == expected => {}
1417 (_, Some(specified @ Disambiguator::Kind(_) | specified @ Disambiguator::Primitive)) => {
1418 self.report_disambiguator_mismatch(path_str,ori_link,specified, Res::Def(kind, id),diag_info);
1423 // item can be non-local e.g. when using #[doc(primitive = "pointer")]
1424 if let Some((src_id, dst_id)) = id
1426 // The `expect_def_id()` should be okay because `local_def_id_to_hir_id`
1427 // would presumably panic if a fake `DefIndex` were passed.
1428 .and_then(|dst_id| {
1429 item.item_id.expect_def_id().as_local().map(|src_id| (src_id, dst_id))
1432 if self.cx.tcx.privacy_access_levels(()).is_exported(src_id)
1433 && !self.cx.tcx.privacy_access_levels(()).is_exported(dst_id)
1435 privacy_error(self.cx, diag_info, path_str);
1442 fn report_disambiguator_mismatch(
1445 ori_link: &MarkdownLink,
1446 specified: Disambiguator,
1448 diag_info: &DiagnosticInfo<'_>,
1450 // The resolved item did not match the disambiguator; give a better error than 'not found'
1451 let msg = format!("incompatible link kind for `{}`", path_str);
1452 let callback = |diag: &mut Diagnostic, sp: Option<rustc_span::Span>| {
1454 "this link resolved to {} {}, which is not {} {}",
1457 specified.article(),
1460 if let Some(sp) = sp {
1461 diag.span_label(sp, ¬e);
1465 suggest_disambiguator(resolved, diag, path_str, &ori_link.link, sp);
1467 report_diagnostic(self.cx.tcx, BROKEN_INTRA_DOC_LINKS, &msg, &diag_info, callback);
1470 fn report_rawptr_assoc_feature_gate(&self, dox: &str, ori_link: &MarkdownLink, item: &Item) {
1472 super::source_span_for_markdown_range(self.cx.tcx, dox, &ori_link.range, &item.attrs)
1473 .unwrap_or_else(|| item.attr_span(self.cx.tcx));
1474 rustc_session::parse::feature_err(
1475 &self.cx.tcx.sess.parse_sess,
1476 sym::intra_doc_pointers,
1478 "linking to associated items of raw pointers is experimental",
1480 .note("rustdoc does not allow disambiguating between `*const` and `*mut`, and pointers are unstable until it does")
1484 fn resolve_with_disambiguator_cached(
1486 key: ResolutionInfo,
1487 diag: DiagnosticInfo<'_>,
1488 cache_resolution_failure: bool,
1489 ) -> Option<(Res, Option<UrlFragment>)> {
1490 if let Some(ref cached) = self.visited_links.get(&key) {
1493 return Some(cached.res.clone());
1495 None if cache_resolution_failure => return None,
1497 // Although we hit the cache and found a resolution error, this link isn't
1498 // supposed to cache those. Run link resolution again to emit the expected
1499 // resolution error.
1504 let res = self.resolve_with_disambiguator(&key, diag);
1506 // Cache only if resolved successfully - don't silence duplicate errors
1507 if let Some(res) = res {
1508 // Store result for the actual namespace
1509 self.visited_links.insert(key, Some(CachedLink { res: res.clone() }));
1513 if cache_resolution_failure {
1514 // For reference-style links we only want to report one resolution error
1515 // so let's cache them as well.
1516 self.visited_links.insert(key, None);
1523 /// After parsing the disambiguator, resolve the main part of the link.
1524 // FIXME(jynelson): wow this is just so much
1525 fn resolve_with_disambiguator(
1527 key: &ResolutionInfo,
1528 diag: DiagnosticInfo<'_>,
1529 ) -> Option<(Res, Option<UrlFragment>)> {
1530 let disambiguator = key.dis;
1531 let path_str = &key.path_str;
1532 let item_id = key.item_id;
1533 let base_node = key.module_id;
1534 let extra_fragment = &key.extra_fragment;
1536 match disambiguator.map(Disambiguator::ns) {
1537 Some(expected_ns @ (ValueNS | TypeNS)) => {
1538 match self.resolve(path_str, expected_ns, item_id, base_node, extra_fragment) {
1539 Ok(res) => Some(res),
1540 Err(ErrorKind::Resolve(box mut kind)) => {
1541 // We only looked in one namespace. Try to give a better error if possible.
1542 if kind.full_res().is_none() {
1543 let other_ns = if expected_ns == ValueNS { TypeNS } else { ValueNS };
1544 // FIXME: really it should be `resolution_failure` that does this, not `resolve_with_disambiguator`
1545 // See https://github.com/rust-lang/rust/pull/76955#discussion_r493953382 for a good approach
1546 for new_ns in [other_ns, MacroNS] {
1547 if let Some(res) = self.check_full_res(
1554 kind = ResolutionFailure::WrongNamespace { res, expected_ns };
1559 resolution_failure(self, diag, path_str, disambiguator, smallvec![kind]);
1560 // This could just be a normal link or a broken link
1561 // we could potentially check if something is
1562 // "intra-doc-link-like" and warn in that case.
1565 Err(ErrorKind::AnchorFailure(msg)) => {
1566 anchor_failure(self.cx, diag, msg);
1573 let mut candidates = PerNS {
1575 .resolve_macro(path_str, item_id, base_node)
1576 .map(|res| (res, extra_fragment.clone().map(UrlFragment::UserWritten))),
1577 type_ns: match self.resolve(
1585 debug!("got res in TypeNS: {:?}", res);
1588 Err(ErrorKind::AnchorFailure(msg)) => {
1589 anchor_failure(self.cx, diag, msg);
1592 Err(ErrorKind::Resolve(box kind)) => Err(kind),
1594 value_ns: match self.resolve(
1602 Err(ErrorKind::AnchorFailure(msg)) => {
1603 anchor_failure(self.cx, diag, msg);
1606 Err(ErrorKind::Resolve(box kind)) => Err(kind),
1608 .and_then(|(res, fragment)| {
1609 // Constructors are picked up in the type namespace.
1611 Res::Def(DefKind::Ctor(..), _) => {
1612 Err(ResolutionFailure::WrongNamespace { res, expected_ns: TypeNS })
1615 match (fragment, extra_fragment.clone()) {
1616 (Some(fragment), Some(_)) => {
1617 // Shouldn't happen but who knows?
1618 Ok((res, Some(fragment)))
1620 (fragment, None) => Ok((res, fragment)),
1621 (None, fragment) => {
1622 Ok((res, fragment.map(UrlFragment::UserWritten)))
1630 let len = candidates.iter().filter(|res| res.is_ok()).count();
1638 candidates.into_iter().filter_map(|res| res.err()).collect(),
1640 // this could just be a normal link
1645 Some(candidates.into_iter().find_map(|res| res.ok()).unwrap())
1646 } else if len == 2 && is_derive_trait_collision(&candidates) {
1647 Some(candidates.type_ns.unwrap())
1649 if is_derive_trait_collision(&candidates) {
1650 candidates.macro_ns = Err(ResolutionFailure::Dummy);
1652 // If we're reporting an ambiguity, don't mention the namespaces that failed
1653 let candidates = candidates.map(|candidate| candidate.ok().map(|(res, _)| res));
1654 ambiguity_error(self.cx, diag, path_str, candidates.present_items().collect());
1659 match self.resolve_macro(path_str, item_id, base_node) {
1660 Ok(res) => Some((res, extra_fragment.clone().map(UrlFragment::UserWritten))),
1662 // `resolve_macro` only looks in the macro namespace. Try to give a better error if possible.
1663 for ns in [TypeNS, ValueNS] {
1664 if let Some(res) = self.check_full_res(
1672 ResolutionFailure::WrongNamespace { res, expected_ns: MacroNS };
1676 resolution_failure(self, diag, path_str, disambiguator, smallvec![kind]);
1685 /// Get the section of a link between the backticks,
1686 /// or the whole link if there aren't any backticks.
1694 fn range_between_backticks(ori_link: &MarkdownLink) -> Range<usize> {
1695 let after_first_backtick_group = ori_link.link.bytes().position(|b| b != b'`').unwrap_or(0);
1696 let before_second_backtick_group = ori_link
1699 .skip(after_first_backtick_group)
1700 .position(|b| b == b'`')
1701 .unwrap_or(ori_link.link.len());
1702 (ori_link.range.start + after_first_backtick_group)
1703 ..(ori_link.range.start + before_second_backtick_group)
1706 /// Returns true if we should ignore `link` due to it being unlikely
1707 /// that it is an intra-doc link. `link` should still have disambiguators
1708 /// if there were any.
1710 /// The difference between this and [`should_ignore_link()`] is that this
1711 /// check should only be used on links that still have disambiguators.
1712 fn should_ignore_link_with_disambiguators(link: &str) -> bool {
1713 link.contains(|ch: char| !(ch.is_alphanumeric() || ":_<>, !*&;@()".contains(ch)))
1716 /// Returns true if we should ignore `path_str` due to it being unlikely
1717 /// that it is an intra-doc link.
1718 fn should_ignore_link(path_str: &str) -> bool {
1719 path_str.contains(|ch: char| !(ch.is_alphanumeric() || ":_<>, !*&;".contains(ch)))
1722 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
1723 /// Disambiguators for a link.
1724 enum Disambiguator {
1727 /// This is buggy, see <https://github.com/rust-lang/rust/pull/77875#discussion_r503583103>
1729 /// `struct@` or `f()`
1732 Namespace(Namespace),
1735 impl Disambiguator {
1736 /// Given a link, parse and return `(disambiguator, path_str, link_text)`.
1738 /// This returns `Ok(Some(...))` if a disambiguator was found,
1739 /// `Ok(None)` if no disambiguator was found, or `Err(...)`
1740 /// if there was a problem with the disambiguator.
1741 fn from_str(link: &str) -> Result<Option<(Self, &str, &str)>, (String, Range<usize>)> {
1742 use Disambiguator::{Kind, Namespace as NS, Primitive};
1744 if let Some(idx) = link.find('@') {
1745 let (prefix, rest) = link.split_at(idx);
1746 let d = match prefix {
1747 "struct" => Kind(DefKind::Struct),
1748 "enum" => Kind(DefKind::Enum),
1749 "trait" => Kind(DefKind::Trait),
1750 "union" => Kind(DefKind::Union),
1751 "module" | "mod" => Kind(DefKind::Mod),
1752 "const" | "constant" => Kind(DefKind::Const),
1753 "static" => Kind(DefKind::Static(Mutability::Not)),
1754 "function" | "fn" | "method" => Kind(DefKind::Fn),
1755 "derive" => Kind(DefKind::Macro(MacroKind::Derive)),
1756 "type" => NS(Namespace::TypeNS),
1757 "value" => NS(Namespace::ValueNS),
1758 "macro" => NS(Namespace::MacroNS),
1759 "prim" | "primitive" => Primitive,
1760 _ => return Err((format!("unknown disambiguator `{}`", prefix), 0..idx)),
1762 Ok(Some((d, &rest[1..], &rest[1..])))
1765 ("!()", DefKind::Macro(MacroKind::Bang)),
1766 ("!{}", DefKind::Macro(MacroKind::Bang)),
1767 ("![]", DefKind::Macro(MacroKind::Bang)),
1768 ("()", DefKind::Fn),
1769 ("!", DefKind::Macro(MacroKind::Bang)),
1771 for (suffix, kind) in suffixes {
1772 if let Some(path_str) = link.strip_suffix(suffix) {
1773 // Avoid turning `!` or `()` into an empty string
1774 if !path_str.is_empty() {
1775 return Ok(Some((Kind(kind), path_str, link)));
1783 fn ns(self) -> Namespace {
1785 Self::Namespace(n) => n,
1787 k.ns().expect("only DefKinds with a valid namespace can be disambiguators")
1789 Self::Primitive => TypeNS,
1793 fn article(self) -> &'static str {
1795 Self::Namespace(_) => panic!("article() doesn't make sense for namespaces"),
1796 Self::Kind(k) => k.article(),
1797 Self::Primitive => "a",
1801 fn descr(self) -> &'static str {
1803 Self::Namespace(n) => n.descr(),
1804 // HACK(jynelson): the source of `DefKind::descr` only uses the DefId for
1805 // printing "module" vs "crate" so using the wrong ID is not a huge problem
1806 Self::Kind(k) => k.descr(CRATE_DEF_ID.to_def_id()),
1807 Self::Primitive => "builtin type",
1812 /// A suggestion to show in a diagnostic.
1815 Prefix(&'static str),
1820 /// `foo` without any disambiguator
1821 RemoveDisambiguator,
1825 fn descr(&self) -> Cow<'static, str> {
1827 Self::Prefix(x) => format!("prefix with `{}@`", x).into(),
1828 Self::Function => "add parentheses".into(),
1829 Self::Macro => "add an exclamation mark".into(),
1830 Self::RemoveDisambiguator => "remove the disambiguator".into(),
1834 fn as_help(&self, path_str: &str) -> String {
1835 // FIXME: if this is an implied shortcut link, it's bad style to suggest `@`
1837 Self::Prefix(prefix) => format!("{}@{}", prefix, path_str),
1838 Self::Function => format!("{}()", path_str),
1839 Self::Macro => format!("{}!", path_str),
1840 Self::RemoveDisambiguator => path_str.into(),
1848 sp: rustc_span::Span,
1849 ) -> Vec<(rustc_span::Span, String)> {
1850 let inner_sp = match ori_link.find('(') {
1851 Some(index) => sp.with_hi(sp.lo() + BytePos(index as _)),
1854 let inner_sp = match ori_link.find('!') {
1855 Some(index) => inner_sp.with_hi(inner_sp.lo() + BytePos(index as _)),
1858 let inner_sp = match ori_link.find('@') {
1859 Some(index) => inner_sp.with_lo(inner_sp.lo() + BytePos(index as u32 + 1)),
1863 Self::Prefix(prefix) => {
1864 // FIXME: if this is an implied shortcut link, it's bad style to suggest `@`
1865 let mut sugg = vec![(sp.with_hi(inner_sp.lo()), format!("{}@", prefix))];
1866 if sp.hi() != inner_sp.hi() {
1867 sugg.push((inner_sp.shrink_to_hi().with_hi(sp.hi()), String::new()));
1872 let mut sugg = vec![(inner_sp.shrink_to_hi().with_hi(sp.hi()), "()".to_string())];
1873 if sp.lo() != inner_sp.lo() {
1874 sugg.push((inner_sp.shrink_to_lo().with_lo(sp.lo()), String::new()));
1879 let mut sugg = vec![(inner_sp.shrink_to_hi(), "!".to_string())];
1880 if sp.lo() != inner_sp.lo() {
1881 sugg.push((inner_sp.shrink_to_lo().with_lo(sp.lo()), String::new()));
1885 Self::RemoveDisambiguator => vec![(sp, path_str.into())],
1890 /// Reports a diagnostic for an intra-doc link.
1892 /// If no link range is provided, or the source span of the link cannot be determined, the span of
1893 /// the entire documentation block is used for the lint. If a range is provided but the span
1894 /// calculation fails, a note is added to the diagnostic pointing to the link in the markdown.
1896 /// The `decorate` callback is invoked in all cases to allow further customization of the
1897 /// diagnostic before emission. If the span of the link was able to be determined, the second
1898 /// parameter of the callback will contain it, and the primary span of the diagnostic will be set
1900 fn report_diagnostic(
1902 lint: &'static Lint,
1904 DiagnosticInfo { item, ori_link: _, dox, link_range }: &DiagnosticInfo<'_>,
1905 decorate: impl FnOnce(&mut Diagnostic, Option<rustc_span::Span>),
1907 let Some(hir_id) = DocContext::as_local_hir_id(tcx, item.item_id)
1909 // If non-local, no need to check anything.
1910 info!("ignoring warning from parent crate: {}", msg);
1914 let sp = item.attr_span(tcx);
1916 tcx.struct_span_lint_hir(lint, hir_id, sp, |lint| {
1917 let mut diag = lint.build(msg);
1920 super::source_span_for_markdown_range(tcx, dox, link_range, &item.attrs).map(|sp| {
1921 if dox.as_bytes().get(link_range.start) == Some(&b'`')
1922 && dox.as_bytes().get(link_range.end - 1) == Some(&b'`')
1924 sp.with_lo(sp.lo() + BytePos(1)).with_hi(sp.hi() - BytePos(1))
1930 if let Some(sp) = span {
1933 // blah blah blah\nblah\nblah [blah] blah blah\nblah blah
1936 // last_new_line_offset
1937 let last_new_line_offset = dox[..link_range.start].rfind('\n').map_or(0, |n| n + 1);
1938 let line = dox[last_new_line_offset..].lines().next().unwrap_or("");
1940 // Print the line containing the `link_range` and manually mark it with '^'s.
1942 "the link appears in this line:\n\n{line}\n\
1943 {indicator: <before$}{indicator:^<found$}",
1946 before = link_range.start - last_new_line_offset,
1947 found = link_range.len(),
1951 decorate(&mut diag, span);
1957 /// Reports a link that failed to resolve.
1959 /// This also tries to resolve any intermediate path segments that weren't
1960 /// handled earlier. For example, if passed `Item::Crate(std)` and `path_str`
1961 /// `std::io::Error::x`, this will resolve `std::io::Error`.
1962 fn resolution_failure(
1963 collector: &mut LinkCollector<'_, '_>,
1964 diag_info: DiagnosticInfo<'_>,
1966 disambiguator: Option<Disambiguator>,
1967 kinds: SmallVec<[ResolutionFailure<'_>; 3]>,
1969 let tcx = collector.cx.tcx;
1972 BROKEN_INTRA_DOC_LINKS,
1973 &format!("unresolved link to `{}`", path_str),
1976 let item = |res: Res| format!("the {} `{}`", res.descr(), res.name(tcx),);
1977 let assoc_item_not_allowed = |res: Res| {
1978 let name = res.name(tcx);
1980 "`{}` is {} {}, not a module or type, and cannot have associated items",
1986 // ignore duplicates
1987 let mut variants_seen = SmallVec::<[_; 3]>::new();
1988 for mut failure in kinds {
1989 let variant = std::mem::discriminant(&failure);
1990 if variants_seen.contains(&variant) {
1993 variants_seen.push(variant);
1995 if let ResolutionFailure::NotResolved {
2004 let item_id = *item_id;
2005 let module_id = *module_id;
2006 // FIXME(jynelson): this might conflict with my `Self` fix in #76467
2007 // FIXME: maybe use itertools `collect_tuple` instead?
2008 fn split(path: &str) -> Option<(&str, &str)> {
2009 let mut splitter = path.rsplitn(2, "::");
2010 splitter.next().and_then(|right| splitter.next().map(|left| (left, right)))
2013 // Check if _any_ parent of the path gets resolved.
2014 // If so, report it and say the first which failed; if not, say the first path segment didn't resolve.
2015 let mut name = path_str;
2017 let Some((start, end)) = split(name) else {
2018 // avoid bug that marked [Quux::Z] as missing Z, not Quux
2019 if partial_res.is_none() {
2020 *unresolved = name.into();
2025 for ns in [TypeNS, ValueNS, MacroNS] {
2027 collector.check_full_res(ns, start, item_id, module_id, &None)
2029 debug!("found partial_res={:?}", res);
2030 *partial_res = Some(res);
2031 *unresolved = end.into();
2035 *unresolved = end.into();
2038 let last_found_module = match *partial_res {
2039 Some(Res::Def(DefKind::Mod, id)) => Some(id),
2040 None => Some(module_id),
2043 // See if this was a module: `[path]` or `[std::io::nope]`
2044 if let Some(module) = last_found_module {
2045 let note = if partial_res.is_some() {
2046 // Part of the link resolved; e.g. `std::io::nonexistent`
2047 let module_name = tcx.item_name(module);
2048 format!("no item named `{}` in module `{}`", unresolved, module_name)
2050 // None of the link resolved; e.g. `Notimported`
2051 format!("no item named `{}` in scope", unresolved)
2053 if let Some(span) = sp {
2054 diag.span_label(span, ¬e);
2059 // If the link has `::` in it, assume it was meant to be an intra-doc link.
2060 // Otherwise, the `[]` might be unrelated.
2061 // FIXME: don't show this for autolinks (`<>`), `()` style links, or reference links
2062 if !path_str.contains("::") {
2063 diag.help(r#"to escape `[` and `]` characters, add '\' before them like `\[` or `\]`"#);
2069 // Otherwise, it must be an associated item or variant
2070 let res = partial_res.expect("None case was handled by `last_found_module`");
2071 let name = res.name(tcx);
2072 let kind = match res {
2073 Res::Def(kind, _) => Some(kind),
2074 Res::Primitive(_) => None,
2076 let path_description = if let Some(kind) = kind {
2078 Mod | ForeignMod => "inner item",
2079 Struct => "field or associated item",
2080 Enum | Union => "variant or associated item",
2098 let note = assoc_item_not_allowed(res);
2099 if let Some(span) = sp {
2100 diag.span_label(span, ¬e);
2106 Trait | TyAlias | ForeignTy | OpaqueTy | TraitAlias | TyParam
2107 | Static(_) => "associated item",
2108 Impl | GlobalAsm => unreachable!("not a path"),
2114 "the {} `{}` has no {} named `{}`",
2117 disambiguator.map_or(path_description, |d| d.descr()),
2120 if let Some(span) = sp {
2121 diag.span_label(span, ¬e);
2128 let note = match failure {
2129 ResolutionFailure::NotResolved { .. } => unreachable!("handled above"),
2130 ResolutionFailure::Dummy => continue,
2131 ResolutionFailure::WrongNamespace { res, expected_ns } => {
2132 suggest_disambiguator(res, diag, path_str, diag_info.ori_link, sp);
2135 "this link resolves to {}, which is not in the {} namespace",
2140 ResolutionFailure::NoParentItem => {
2141 // FIXME(eddyb) this doesn't belong here, whatever made
2142 // the `ResolutionFailure::NoParentItem` should emit an
2143 // immediate or delayed `span_bug` about the issue.
2144 tcx.sess.delay_span_bug(
2145 sp.unwrap_or(DUMMY_SP),
2146 "intra-doc link missing parent item",
2149 "BUG: all intra-doc links should have a parent item".to_owned()
2151 ResolutionFailure::MalformedGenerics(variant) => match variant {
2152 MalformedGenerics::UnbalancedAngleBrackets => {
2153 String::from("unbalanced angle brackets")
2155 MalformedGenerics::MissingType => {
2156 String::from("missing type for generic parameters")
2158 MalformedGenerics::HasFullyQualifiedSyntax => {
2159 diag.note("see https://github.com/rust-lang/rust/issues/74563 for more information");
2160 String::from("fully-qualified syntax is unsupported")
2162 MalformedGenerics::InvalidPathSeparator => {
2163 String::from("has invalid path separator")
2165 MalformedGenerics::TooManyAngleBrackets => {
2166 String::from("too many angle brackets")
2168 MalformedGenerics::EmptyAngleBrackets => {
2169 String::from("empty angle brackets")
2173 if let Some(span) = sp {
2174 diag.span_label(span, ¬e);
2183 /// Report an anchor failure.
2184 fn anchor_failure(cx: &DocContext<'_>, diag_info: DiagnosticInfo<'_>, failure: AnchorFailure) {
2185 let (msg, anchor_idx) = match failure {
2186 AnchorFailure::MultipleAnchors => {
2187 (format!("`{}` contains multiple anchors", diag_info.ori_link), 1)
2189 AnchorFailure::RustdocAnchorConflict(res) => (
2191 "`{}` contains an anchor, but links to {kind}s are already anchored",
2199 report_diagnostic(cx.tcx, BROKEN_INTRA_DOC_LINKS, &msg, &diag_info, |diag, sp| {
2200 if let Some(mut sp) = sp {
2201 if let Some((fragment_offset, _)) =
2202 diag_info.ori_link.char_indices().filter(|(_, x)| *x == '#').nth(anchor_idx)
2204 sp = sp.with_lo(sp.lo() + BytePos(fragment_offset as _));
2206 diag.span_label(sp, "invalid anchor");
2208 if let AnchorFailure::RustdocAnchorConflict(Res::Primitive(_)) = failure {
2209 if let Some(sp) = sp {
2210 span_bug!(sp, "anchors should be allowed now");
2212 bug!("anchors should be allowed now");
2218 /// Report an error in the link disambiguator.
2219 fn disambiguator_error(
2220 cx: &DocContext<'_>,
2221 mut diag_info: DiagnosticInfo<'_>,
2222 disambiguator_range: Range<usize>,
2225 diag_info.link_range = disambiguator_range;
2226 report_diagnostic(cx.tcx, BROKEN_INTRA_DOC_LINKS, msg, &diag_info, |diag, _sp| {
2228 "see {}/rustdoc/linking-to-items-by-name.html#namespaces-and-disambiguators for more info about disambiguators",
2229 crate::DOC_RUST_LANG_ORG_CHANNEL
2235 /// Report an ambiguity error, where there were multiple possible resolutions.
2237 cx: &DocContext<'_>,
2238 diag_info: DiagnosticInfo<'_>,
2240 candidates: Vec<Res>,
2242 let mut msg = format!("`{}` is ", path_str);
2244 match candidates.as_slice() {
2245 [first_def, second_def] => {
2247 "both {} {} and {} {}",
2248 first_def.article(),
2250 second_def.article(),
2255 let mut candidates = candidates.iter().peekable();
2256 while let Some(res) = candidates.next() {
2257 if candidates.peek().is_some() {
2258 msg += &format!("{} {}, ", res.article(), res.descr());
2260 msg += &format!("and {} {}", res.article(), res.descr());
2266 report_diagnostic(cx.tcx, BROKEN_INTRA_DOC_LINKS, &msg, &diag_info, |diag, sp| {
2267 if let Some(sp) = sp {
2268 diag.span_label(sp, "ambiguous link");
2270 diag.note("ambiguous link");
2273 for res in candidates {
2274 suggest_disambiguator(res, diag, path_str, diag_info.ori_link, sp);
2279 /// In case of an ambiguity or mismatched disambiguator, suggest the correct
2281 fn suggest_disambiguator(
2283 diag: &mut Diagnostic,
2286 sp: Option<rustc_span::Span>,
2288 let suggestion = res.disambiguator_suggestion();
2289 let help = format!("to link to the {}, {}", res.descr(), suggestion.descr());
2291 if let Some(sp) = sp {
2292 let mut spans = suggestion.as_help_span(path_str, ori_link, sp);
2293 if spans.len() > 1 {
2294 diag.multipart_suggestion(&help, spans, Applicability::MaybeIncorrect);
2296 let (sp, suggestion_text) = spans.pop().unwrap();
2297 diag.span_suggestion_verbose(sp, &help, suggestion_text, Applicability::MaybeIncorrect);
2300 diag.help(&format!("{}: {}", help, suggestion.as_help(path_str)));
2304 /// Report a link from a public item to a private one.
2305 fn privacy_error(cx: &DocContext<'_>, diag_info: &DiagnosticInfo<'_>, path_str: &str) {
2307 let item_name = match diag_info.item.name {
2312 None => "<unknown>",
2315 format!("public documentation for `{}` links to private item `{}`", item_name, path_str);
2317 report_diagnostic(cx.tcx, PRIVATE_INTRA_DOC_LINKS, &msg, diag_info, |diag, sp| {
2318 if let Some(sp) = sp {
2319 diag.span_label(sp, "this item is private");
2322 let note_msg = if cx.render_options.document_private {
2323 "this link resolves only because you passed `--document-private-items`, but will break without"
2325 "this link will resolve properly if you pass `--document-private-items`"
2327 diag.note(note_msg);
2331 /// Given an enum variant's res, return the res of its enum and the associated fragment.
2333 cx: &DocContext<'_>,
2335 ) -> Result<(Res, Option<ItemFragment>), ErrorKind<'static>> {
2337 .parent(res.def_id(cx.tcx))
2339 let parent_def = Res::Def(DefKind::Enum, parent);
2340 let variant = cx.tcx.expect_variant_res(res.as_hir_res().unwrap());
2341 (parent_def, Some(ItemFragment(FragmentKind::Variant, variant.def_id)))
2343 .ok_or_else(|| ResolutionFailure::NoParentItem.into())
2346 /// Resolve a primitive type or value.
2347 fn resolve_primitive(path_str: &str, ns: Namespace) -> Option<Res> {
2351 use PrimitiveType::*;
2352 let prim = match path_str {
2368 "bool" | "true" | "false" => Bool,
2369 "str" | "&str" => Str,
2370 // See #80181 for why these don't have symbols associated.
2375 "pointer" | "*const" | "*mut" => RawPointer,
2376 "reference" | "&" | "&mut" => Reference,
2378 "never" | "!" => Never,
2381 debug!("resolved primitives {:?}", prim);
2382 Some(Res::Primitive(prim))
2385 fn strip_generics_from_path(path_str: &str) -> Result<String, ResolutionFailure<'static>> {
2386 let mut stripped_segments = vec![];
2387 let mut path = path_str.chars().peekable();
2388 let mut segment = Vec::new();
2390 while let Some(chr) = path.next() {
2393 if path.next_if_eq(&':').is_some() {
2394 let stripped_segment =
2395 strip_generics_from_path_segment(mem::take(&mut segment))?;
2396 if !stripped_segment.is_empty() {
2397 stripped_segments.push(stripped_segment);
2400 return Err(ResolutionFailure::MalformedGenerics(
2401 MalformedGenerics::InvalidPathSeparator,
2410 return Err(ResolutionFailure::MalformedGenerics(
2411 MalformedGenerics::TooManyAngleBrackets,
2415 return Err(ResolutionFailure::MalformedGenerics(
2416 MalformedGenerics::EmptyAngleBrackets,
2422 while let Some(chr) = path.next_if(|c| *c != '>') {
2429 _ => segment.push(chr),
2431 trace!("raw segment: {:?}", segment);
2434 if !segment.is_empty() {
2435 let stripped_segment = strip_generics_from_path_segment(segment)?;
2436 if !stripped_segment.is_empty() {
2437 stripped_segments.push(stripped_segment);
2441 debug!("path_str: {:?}\nstripped segments: {:?}", path_str, &stripped_segments);
2443 let stripped_path = stripped_segments.join("::");
2445 if !stripped_path.is_empty() {
2448 Err(ResolutionFailure::MalformedGenerics(MalformedGenerics::MissingType))
2452 fn strip_generics_from_path_segment(
2454 ) -> Result<String, ResolutionFailure<'static>> {
2455 let mut stripped_segment = String::new();
2456 let mut param_depth = 0;
2458 let mut latest_generics_chunk = String::new();
2463 latest_generics_chunk.clear();
2464 } else if c == '>' {
2466 if latest_generics_chunk.contains(" as ") {
2467 // The segment tries to use fully-qualified syntax, which is currently unsupported.
2468 // Give a helpful error message instead of completely ignoring the angle brackets.
2469 return Err(ResolutionFailure::MalformedGenerics(
2470 MalformedGenerics::HasFullyQualifiedSyntax,
2474 if param_depth == 0 {
2475 stripped_segment.push(c);
2477 latest_generics_chunk.push(c);
2482 if param_depth == 0 {
2483 Ok(stripped_segment)
2485 // The segment has unbalanced angle brackets, e.g. `Vec<T` or `Vec<T>>`
2486 Err(ResolutionFailure::MalformedGenerics(MalformedGenerics::UnbalancedAngleBrackets))