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 rustc_data_structures::{fx::FxHashMap, intern::Interned, stable_set::FxHashSet};
6 use rustc_errors::{Applicability, Diagnostic};
12 use rustc_hir::def_id::{CrateNum, DefId, CRATE_DEF_ID};
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};
21 use pulldown_cmark::LinkType;
24 use std::convert::{TryFrom, TryInto};
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 crate use early::early_resolve_intra_doc_links;
40 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 /// Top-level errors emitted by this pass.
55 Resolve(Box<ResolutionFailure<'a>>),
56 AnchorFailure(AnchorFailure),
59 impl<'a> From<ResolutionFailure<'a>> for ErrorKind<'a> {
60 fn from(err: ResolutionFailure<'a>) -> Self {
61 ErrorKind::Resolve(box err)
65 #[derive(Copy, Clone, Debug, Hash)]
68 Primitive(PrimitiveType),
71 type ResolveRes = rustc_hir::def::Res<rustc_ast::NodeId>;
74 fn descr(self) -> &'static str {
76 Res::Def(kind, id) => ResolveRes::Def(kind, id).descr(),
77 Res::Primitive(_) => "builtin type",
81 fn article(self) -> &'static str {
83 Res::Def(kind, id) => ResolveRes::Def(kind, id).article(),
84 Res::Primitive(_) => "a",
88 fn name(self, tcx: TyCtxt<'_>) -> Symbol {
90 Res::Def(_, id) => tcx.item_name(id),
91 Res::Primitive(prim) => prim.as_sym(),
95 fn def_id(self, tcx: TyCtxt<'_>) -> DefId {
97 Res::Def(_, id) => id,
98 Res::Primitive(prim) => *PrimitiveType::primitive_locations(tcx).get(&prim).unwrap(),
102 fn as_hir_res(self) -> Option<rustc_hir::def::Res> {
104 Res::Def(kind, id) => Some(rustc_hir::def::Res::Def(kind, id)),
105 // FIXME: maybe this should handle the subset of PrimitiveType that fits into hir::PrimTy?
106 Res::Primitive(_) => None,
110 /// Used for error reporting.
111 fn disambiguator_suggestion(self) -> Suggestion {
112 let kind = match self {
113 Res::Primitive(_) => return Suggestion::Prefix("prim"),
114 Res::Def(kind, _) => kind,
116 if kind == DefKind::Macro(MacroKind::Bang) {
117 return Suggestion::Macro;
118 } else if kind == DefKind::Fn || kind == DefKind::AssocFn {
119 return Suggestion::Function;
120 } else if kind == DefKind::Field {
121 return Suggestion::RemoveDisambiguator;
124 let prefix = match kind {
125 DefKind::Struct => "struct",
126 DefKind::Enum => "enum",
127 DefKind::Trait => "trait",
128 DefKind::Union => "union",
129 DefKind::Mod => "mod",
130 DefKind::Const | DefKind::ConstParam | DefKind::AssocConst | DefKind::AnonConst => {
133 DefKind::Static => "static",
134 DefKind::Macro(MacroKind::Derive) => "derive",
135 // Now handle things that don't have a specific disambiguator
138 .expect("tried to calculate a disambiguator for a def without a namespace?")
140 Namespace::TypeNS => "type",
141 Namespace::ValueNS => "value",
142 Namespace::MacroNS => "macro",
146 Suggestion::Prefix(prefix)
150 impl TryFrom<ResolveRes> for Res {
153 fn try_from(res: ResolveRes) -> Result<Self, ()> {
154 use rustc_hir::def::Res::*;
156 Def(kind, id) => Ok(Res::Def(kind, id)),
157 PrimTy(prim) => Ok(Res::Primitive(PrimitiveType::from_hir(prim))),
159 NonMacroAttr(..) | Err => Result::Err(()),
160 other => bug!("unrecognized res {:?}", other),
165 /// A link failed to resolve.
167 enum ResolutionFailure<'a> {
168 /// This resolved, but with the wrong namespace.
170 /// What the link resolved to.
172 /// The expected namespace for the resolution, determined from the link's disambiguator.
174 /// E.g., for `[fn@Result]` this is [`Namespace::ValueNS`],
175 /// even though `Result`'s actual namespace is [`Namespace::TypeNS`].
176 expected_ns: Namespace,
178 /// The link failed to resolve. [`resolution_failure`] should look to see if there's
179 /// a more helpful error that can be given.
181 /// Item on which the link is resolved, used for resolving `Self`.
183 /// The scope the link was resolved in.
185 /// If part of the link resolved, this has the `Res`.
187 /// In `[std::io::Error::x]`, `std::io::Error` would be a partial resolution.
188 partial_res: Option<Res>,
189 /// The remaining unresolved path segments.
191 /// In `[std::io::Error::x]`, `x` would be unresolved.
192 unresolved: Cow<'a, str>,
194 /// This happens when rustdoc can't determine the parent scope for an item.
195 /// It is always a bug in rustdoc.
197 /// This link has malformed generic parameters; e.g., the angle brackets are unbalanced.
198 MalformedGenerics(MalformedGenerics),
199 /// Used to communicate that this should be ignored, but shouldn't be reported to the user.
201 /// This happens when there is no disambiguator and one of the namespaces
202 /// failed to resolve.
207 enum MalformedGenerics {
208 /// This link has unbalanced angle brackets.
210 /// For example, `Vec<T` should trigger this, as should `Vec<T>>`.
211 UnbalancedAngleBrackets,
212 /// The generics are not attached to a type.
214 /// For example, `<T>` should trigger this.
216 /// This is detected by checking if the path is empty after the generics are stripped.
218 /// The link uses fully-qualified syntax, which is currently unsupported.
220 /// For example, `<Vec as IntoIterator>::into_iter` should trigger this.
222 /// This is detected by checking if ` as ` (the keyword `as` with spaces around it) is inside
224 HasFullyQualifiedSyntax,
225 /// The link has an invalid path separator.
227 /// For example, `Vec:<T>:new()` should trigger this. Note that `Vec:new()` will **not**
228 /// trigger this because it has no generics and thus [`strip_generics_from_path`] will not be
231 /// Note that this will also **not** be triggered if the invalid path separator is inside angle
232 /// brackets because rustdoc mostly ignores what's inside angle brackets (except for
233 /// [`HasFullyQualifiedSyntax`](MalformedGenerics::HasFullyQualifiedSyntax)).
235 /// This is detected by checking if there is a colon followed by a non-colon in the link.
236 InvalidPathSeparator,
237 /// The link has too many angle brackets.
239 /// For example, `Vec<<T>>` should trigger this.
240 TooManyAngleBrackets,
241 /// The link has empty angle brackets.
243 /// For example, `Vec<>` should trigger this.
247 impl ResolutionFailure<'_> {
248 /// This resolved fully (not just partially) but is erroneous for some other reason
250 /// Returns the full resolution of the link, if present.
251 fn full_res(&self) -> Option<Res> {
253 Self::WrongNamespace { res, expected_ns: _ } => Some(*res),
260 /// User error: `[std#x#y]` is not valid
262 /// The anchor provided by the user conflicts with Rustdoc's generated anchor.
264 /// This is an unfortunate state of affairs. Not every item that can be
265 /// linked to has its own page; sometimes it is a subheading within a page,
266 /// like for associated items. In those cases, rustdoc uses an anchor to
267 /// link to the subheading. Since you can't have two anchors for the same
268 /// link, Rustdoc disallows having a user-specified anchor.
270 /// Most of the time this is fine, because you can just link to the page of
271 /// the item if you want to provide your own anchor.
272 RustdocAnchorConflict(Res),
275 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
276 crate enum UrlFragment {
282 /// Render the fragment, including the leading `#`.
283 crate fn render(&self, s: &mut String, tcx: TyCtxt<'_>) -> std::fmt::Result {
285 UrlFragment::Item(frag) => frag.render(s, tcx),
286 UrlFragment::UserWritten(raw) => write!(s, "#{}", raw),
291 #[derive(Copy, Clone, Debug, Hash, PartialEq, Eq)]
292 crate struct ItemFragment(FragmentKind, DefId);
294 #[derive(Copy, Clone, Debug, Hash, PartialEq, Eq)]
295 crate enum FragmentKind {
307 /// Create a fragment for an associated item.
308 #[instrument(level = "debug")]
309 fn from_assoc_item(item: &ty::AssocItem) -> Self {
310 let def_id = item.def_id;
312 ty::AssocKind::Fn => {
313 if item.defaultness.has_value() {
314 ItemFragment(FragmentKind::Method, def_id)
316 ItemFragment(FragmentKind::TyMethod, def_id)
319 ty::AssocKind::Const => ItemFragment(FragmentKind::AssociatedConstant, def_id),
320 ty::AssocKind::Type => ItemFragment(FragmentKind::AssociatedType, def_id),
324 /// Render the fragment, including the leading `#`.
325 crate fn render(&self, s: &mut String, tcx: TyCtxt<'_>) -> std::fmt::Result {
328 ItemFragment(kind, def_id) => {
329 let name = tcx.item_name(def_id);
331 FragmentKind::Method => write!(s, "method.{}", name),
332 FragmentKind::TyMethod => write!(s, "tymethod.{}", name),
333 FragmentKind::AssociatedConstant => write!(s, "associatedconstant.{}", name),
334 FragmentKind::AssociatedType => write!(s, "associatedtype.{}", name),
335 FragmentKind::StructField => write!(s, "structfield.{}", name),
336 FragmentKind::Variant => write!(s, "variant.{}", name),
337 FragmentKind::VariantField => {
338 let variant = tcx.item_name(tcx.parent(def_id).unwrap());
339 write!(s, "variant.{}.field.{}", variant, name)
347 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
348 struct ResolutionInfo {
351 dis: Option<Disambiguator>,
353 extra_fragment: Option<String>,
357 struct DiagnosticInfo<'a> {
361 link_range: Range<usize>,
364 #[derive(Clone, Debug, Hash)]
366 res: (Res, Option<UrlFragment>),
369 struct LinkCollector<'a, 'tcx> {
370 cx: &'a mut DocContext<'tcx>,
371 /// A stack of modules used to decide what scope to resolve in.
373 /// The last module will be used if the parent scope of the current item is
376 /// Cache the resolved links so we can avoid resolving (and emitting errors for) the same link.
377 /// The link will be `None` if it could not be resolved (i.e. the error was cached).
378 visited_links: FxHashMap<ResolutionInfo, Option<CachedLink>>,
381 impl<'a, 'tcx> LinkCollector<'a, 'tcx> {
382 /// Given a full link, parse it as an [enum struct variant].
384 /// In particular, this will return an error whenever there aren't three
385 /// full path segments left in the link.
387 /// [enum struct variant]: rustc_hir::VariantData::Struct
388 fn variant_field<'path>(
390 path_str: &'path str,
393 ) -> Result<(Res, Option<ItemFragment>), ErrorKind<'path>> {
394 let tcx = self.cx.tcx;
395 let no_res = || ResolutionFailure::NotResolved {
399 unresolved: path_str.into(),
402 debug!("looking for enum variant {}", path_str);
403 let mut split = path_str.rsplitn(3, "::");
404 let variant_field_name = split
406 .map(|f| Symbol::intern(f))
407 .expect("fold_item should ensure link is non-empty");
409 // we're not sure this is a variant at all, so use the full string
410 // If there's no second component, the link looks like `[path]`.
411 // So there's no partial res and we should say the whole link failed to resolve.
412 split.next().map(|f| Symbol::intern(f)).ok_or_else(no_res)?;
415 .map(|f| f.to_owned())
416 // If there's no third component, we saw `[a::b]` before and it failed to resolve.
417 // So there's no partial res.
418 .ok_or_else(no_res)?;
419 let ty_res = self.resolve_path(&path, TypeNS, item_id, module_id).ok_or_else(no_res)?;
422 Res::Def(DefKind::Enum, did) => {
426 .flat_map(|imp| tcx.associated_items(*imp).in_definition_order())
427 .any(|item| item.name == variant_name)
429 // This is just to let `fold_item` know that this shouldn't be considered;
430 // it's a bug for the error to make it to the user
431 return Err(ResolutionFailure::Dummy.into());
433 match tcx.type_of(did).kind() {
434 ty::Adt(def, _) if def.is_enum() => {
435 if let Some(field) = def.all_fields().find(|f| f.name == variant_field_name)
437 Ok((ty_res, Some(ItemFragment(FragmentKind::VariantField, field.did))))
439 Err(ResolutionFailure::NotResolved {
442 partial_res: Some(Res::Def(DefKind::Enum, def.did())),
443 unresolved: variant_field_name.to_string().into(),
451 _ => Err(ResolutionFailure::NotResolved {
454 partial_res: Some(ty_res),
455 unresolved: variant_name.to_string().into(),
461 /// Given a primitive type, try to resolve an associated item.
462 fn resolve_primitive_associated_item(
464 prim_ty: PrimitiveType,
467 ) -> Option<(Res, ItemFragment)> {
468 let tcx = self.cx.tcx;
470 prim_ty.impls(tcx).into_iter().find_map(|&impl_| {
471 tcx.associated_items(impl_)
472 .find_by_name_and_namespace(tcx, Ident::with_dummy_span(item_name), ns, impl_)
474 let fragment = ItemFragment::from_assoc_item(item);
475 (Res::Primitive(prim_ty), fragment)
480 /// Resolves a string as a macro.
482 /// FIXME(jynelson): Can this be unified with `resolve()`?
488 ) -> Result<Res, ResolutionFailure<'a>> {
489 self.cx.enter_resolver(|resolver| {
490 // NOTE: this needs 2 separate lookups because `resolve_str_path_error` doesn't take
491 // lexical scope into account (it ignores all macros not defined at the mod-level)
492 debug!("resolving {} as a macro in the module {:?}", path_str, module_id);
493 if let Ok((_, res)) =
494 resolver.resolve_str_path_error(DUMMY_SP, path_str, MacroNS, module_id)
496 // don't resolve builtins like `#[derive]`
497 if let Ok(res) = res.try_into() {
501 if let Some(&res) = resolver.all_macros().get(&Symbol::intern(path_str)) {
502 return Ok(res.try_into().unwrap());
504 Err(ResolutionFailure::NotResolved {
508 unresolved: path_str.into(),
513 fn resolve_self_ty(&self, path_str: &str, ns: Namespace, item_id: ItemId) -> Option<Res> {
514 if ns != TypeNS || path_str != "Self" {
518 let tcx = self.cx.tcx;
521 .map(|def_id| match tcx.def_kind(def_id) {
522 def_kind @ (DefKind::AssocFn
523 | DefKind::AssocConst
526 | DefKind::Field) => {
527 let parent_def_id = tcx.parent(def_id).expect("nested item has no parent");
528 if def_kind == DefKind::Field && tcx.def_kind(parent_def_id) == DefKind::Variant
530 tcx.parent(parent_def_id).expect("variant has no parent")
537 .and_then(|self_id| match tcx.def_kind(self_id) {
538 DefKind::Impl => self.def_id_to_res(self_id),
539 def_kind => Some(Res::Def(def_kind, self_id)),
543 /// Convenience wrapper around `resolve_str_path_error`.
545 /// This also handles resolving `true` and `false` as booleans.
546 /// NOTE: `resolve_str_path_error` knows only about paths, not about types.
547 /// Associated items will never be resolved by this function.
555 if let res @ Some(..) = self.resolve_self_ty(path_str, ns, item_id) {
559 let result = self.cx.enter_resolver(|resolver| {
561 .resolve_str_path_error(DUMMY_SP, path_str, ns, module_id)
562 .and_then(|(_, res)| res.try_into())
564 debug!("{} resolved to {:?} in namespace {:?}", path_str, result, ns);
566 // resolver doesn't know about true, false, and types that aren't paths (e.g. `()`)
568 Err(()) => resolve_primitive(path_str, ns),
569 Ok(res) => Some(res),
573 /// Resolves a string as a path within a particular namespace. Returns an
574 /// optional URL fragment in the case of variants and methods.
577 path_str: &'path str,
581 user_fragment: &Option<String>,
582 ) -> Result<(Res, Option<UrlFragment>), ErrorKind<'path>> {
583 let (res, rustdoc_fragment) = self.resolve_inner(path_str, ns, item_id, module_id)?;
584 let chosen_fragment = match (user_fragment, rustdoc_fragment) {
585 (Some(_), Some(r_frag)) => {
586 let diag_res = match r_frag {
587 ItemFragment(_, did) => Res::Def(self.cx.tcx.def_kind(did), did),
589 let failure = AnchorFailure::RustdocAnchorConflict(diag_res);
590 return Err(ErrorKind::AnchorFailure(failure));
592 (Some(u_frag), None) => Some(UrlFragment::UserWritten(u_frag.clone())),
593 (None, Some(r_frag)) => Some(UrlFragment::Item(r_frag)),
594 (None, None) => None,
596 Ok((res, chosen_fragment))
599 fn resolve_inner<'path>(
601 path_str: &'path str,
605 ) -> Result<(Res, Option<ItemFragment>), ErrorKind<'path>> {
606 if let Some(res) = self.resolve_path(path_str, ns, item_id, module_id) {
608 // FIXME(#76467): make this fallthrough to lookup the associated
609 // item a separate function.
610 Res::Def(DefKind::AssocFn | DefKind::AssocConst, _) => assert_eq!(ns, ValueNS),
611 Res::Def(DefKind::AssocTy, _) => assert_eq!(ns, TypeNS),
612 Res::Def(DefKind::Variant, _) => {
613 return handle_variant(self.cx, res);
615 // Not a trait item; just return what we found.
616 _ => return Ok((res, None)),
620 // Try looking for methods and associated items.
621 let mut split = path_str.rsplitn(2, "::");
622 // NB: `split`'s first element is always defined, even if the delimiter was not present.
623 // NB: `item_str` could be empty when resolving in the root namespace (e.g. `::std`).
624 let item_str = split.next().unwrap();
625 let item_name = Symbol::intern(item_str);
626 let path_root = split
628 .map(|f| f.to_owned())
629 // If there's no `::`, it's not an associated item.
630 // So we can be sure that `rustc_resolve` was accurate when it said it wasn't resolved.
632 debug!("found no `::`, assumming {} was correctly not in scope", item_name);
633 ResolutionFailure::NotResolved {
637 unresolved: item_str.into(),
641 // FIXME(#83862): this arbitrarily gives precedence to primitives over modules to support
642 // links to primitives when `#[doc(primitive)]` is present. It should give an ambiguity
643 // error instead and special case *only* modules with `#[doc(primitive)]`, not all
645 resolve_primitive(&path_root, TypeNS)
646 .or_else(|| self.resolve_path(&path_root, TypeNS, item_id, module_id))
648 let (res, fragment) =
649 self.resolve_associated_item(ty_res, item_name, ns, module_id)?;
651 Some(Ok((res, Some(fragment))))
654 if ns == Namespace::ValueNS {
655 self.variant_field(path_str, item_id, module_id)
657 Err(ResolutionFailure::NotResolved {
661 unresolved: path_root.into(),
668 /// Convert a DefId to a Res, where possible.
670 /// This is used for resolving type aliases.
671 fn def_id_to_res(&self, ty_id: DefId) -> Option<Res> {
672 use PrimitiveType::*;
673 Some(match *self.cx.tcx.type_of(ty_id).kind() {
674 ty::Bool => Res::Primitive(Bool),
675 ty::Char => Res::Primitive(Char),
676 ty::Int(ity) => Res::Primitive(ity.into()),
677 ty::Uint(uty) => Res::Primitive(uty.into()),
678 ty::Float(fty) => Res::Primitive(fty.into()),
679 ty::Str => Res::Primitive(Str),
680 ty::Tuple(tys) if tys.is_empty() => Res::Primitive(Unit),
681 ty::Tuple(_) => Res::Primitive(Tuple),
682 ty::Array(..) => Res::Primitive(Array),
683 ty::Slice(_) => Res::Primitive(Slice),
684 ty::RawPtr(_) => Res::Primitive(RawPointer),
685 ty::Ref(..) => Res::Primitive(Reference),
686 ty::FnDef(..) => panic!("type alias to a function definition"),
687 ty::FnPtr(_) => Res::Primitive(Fn),
688 ty::Never => Res::Primitive(Never),
689 ty::Adt(ty::AdtDef(Interned(&ty::AdtDefData { did, .. }, _)), _) | ty::Foreign(did) => {
690 Res::Def(self.cx.tcx.def_kind(did), did)
695 | ty::GeneratorWitness(_)
702 | ty::Error(_) => return None,
706 /// Convert a PrimitiveType to a Ty, where possible.
708 /// This is used for resolving trait impls for primitives
709 fn primitive_type_to_ty(&mut self, prim: PrimitiveType) -> Option<Ty<'tcx>> {
710 use PrimitiveType::*;
711 let tcx = self.cx.tcx;
713 // FIXME: Only simple types are supported here, see if we can support
714 // other types such as Tuple, Array, Slice, etc.
715 // See https://github.com/rust-lang/rust/issues/90703#issuecomment-1004263455
716 Some(tcx.mk_ty(match prim {
721 I8 => ty::Int(ty::IntTy::I8),
722 I16 => ty::Int(ty::IntTy::I16),
723 I32 => ty::Int(ty::IntTy::I32),
724 I64 => ty::Int(ty::IntTy::I64),
725 I128 => ty::Int(ty::IntTy::I128),
726 Isize => ty::Int(ty::IntTy::Isize),
727 F32 => ty::Float(ty::FloatTy::F32),
728 F64 => ty::Float(ty::FloatTy::F64),
729 U8 => ty::Uint(ty::UintTy::U8),
730 U16 => ty::Uint(ty::UintTy::U16),
731 U32 => ty::Uint(ty::UintTy::U32),
732 U64 => ty::Uint(ty::UintTy::U64),
733 U128 => ty::Uint(ty::UintTy::U128),
734 Usize => ty::Uint(ty::UintTy::Usize),
739 /// Resolve an associated item, returning its containing page's `Res`
740 /// and the fragment targeting the associated item on its page.
741 fn resolve_associated_item(
747 ) -> Option<(Res, ItemFragment)> {
748 let tcx = self.cx.tcx;
751 Res::Primitive(prim) => {
752 self.resolve_primitive_associated_item(prim, ns, item_name).or_else(|| {
753 let assoc_item = self
754 .primitive_type_to_ty(prim)
756 resolve_associated_trait_item(ty, module_id, item_name, ns, self.cx)
760 assoc_item.map(|item| {
761 let fragment = ItemFragment::from_assoc_item(&item);
766 Res::Def(DefKind::TyAlias, did) => {
767 // Resolve the link on the type the alias points to.
768 // FIXME: if the associated item is defined directly on the type alias,
769 // it will show up on its documentation page, we should link there instead.
770 let res = self.def_id_to_res(did)?;
771 self.resolve_associated_item(res, item_name, ns, module_id)
774 def_kind @ (DefKind::Struct | DefKind::Union | DefKind::Enum | DefKind::ForeignTy),
777 debug!("looking for associated item named {} for item {:?}", item_name, did);
778 // Checks if item_name is a variant of the `SomeItem` enum
779 if ns == TypeNS && def_kind == DefKind::Enum {
780 match tcx.type_of(did).kind() {
781 ty::Adt(adt_def, _) => {
782 for variant in adt_def.variants() {
783 if variant.name == item_name {
786 ItemFragment(FragmentKind::Variant, variant.def_id),
795 // Checks if item_name belongs to `impl SomeItem`
800 tcx.associated_items(imp).find_by_name_and_namespace(
802 Ident::with_dummy_span(item_name),
808 // There should only ever be one associated item that matches from any inherent impl
810 // Check if item_name belongs to `impl SomeTrait for SomeItem`
811 // FIXME(#74563): This gives precedence to `impl SomeItem`:
812 // Although having both would be ambiguous, use impl version for compatibility's sake.
813 // To handle that properly resolve() would have to support
814 // something like [`ambi_fn`](<SomeStruct as SomeTrait>::ambi_fn)
816 resolve_associated_trait_item(
825 debug!("got associated item {:?}", assoc_item);
827 if let Some(item) = assoc_item {
828 let fragment = ItemFragment::from_assoc_item(&item);
829 return Some((root_res, fragment));
832 if ns != Namespace::ValueNS {
835 debug!("looking for fields named {} for {:?}", item_name, did);
836 // FIXME: this doesn't really belong in `associated_item` (maybe `variant_field` is better?)
837 // NOTE: it's different from variant_field because it only resolves struct fields,
838 // not variant fields (2 path segments, not 3).
840 // We need to handle struct (and union) fields in this code because
841 // syntactically their paths are identical to associated item paths:
842 // `module::Type::field` and `module::Type::Assoc`.
844 // On the other hand, variant fields can't be mistaken for associated
845 // items because they look like this: `module::Type::Variant::field`.
847 // Variants themselves don't need to be handled here, even though
848 // they also look like associated items (`module::Type::Variant`),
849 // because they are real Rust syntax (unlike the intra-doc links
850 // field syntax) and are handled by the compiler's resolver.
851 let def = match tcx.type_of(did).kind() {
852 ty::Adt(def, _) if !def.is_enum() => def,
856 def.non_enum_variant().fields.iter().find(|item| item.name == item_name)?;
857 Some((root_res, ItemFragment(FragmentKind::StructField, field.did)))
859 Res::Def(DefKind::Trait, did) => tcx
860 .associated_items(did)
861 .find_by_name_and_namespace(tcx, Ident::with_dummy_span(item_name), ns, did)
863 let fragment = ItemFragment::from_assoc_item(item);
864 let res = Res::Def(item.kind.as_def_kind(), item.def_id);
871 /// Used for reporting better errors.
873 /// Returns whether the link resolved 'fully' in another namespace.
874 /// 'fully' here means that all parts of the link resolved, not just some path segments.
875 /// This returns the `Res` even if it was erroneous for some reason
876 /// (such as having invalid URL fragments or being in the wrong namespace).
883 extra_fragment: &Option<String>,
885 // resolve() can't be used for macro namespace
886 let result = match ns {
887 Namespace::MacroNS => self
888 .resolve_macro(path_str, item_id, module_id)
889 .map(|res| (res, None))
890 .map_err(ErrorKind::from),
891 Namespace::TypeNS | Namespace::ValueNS => {
892 self.resolve(path_str, ns, item_id, module_id, extra_fragment)
896 let res = match result {
898 if let Some(UrlFragment::Item(ItemFragment(_, id))) = frag {
899 Some(Res::Def(self.cx.tcx.def_kind(id), id))
904 Err(ErrorKind::Resolve(box kind)) => kind.full_res(),
905 Err(ErrorKind::AnchorFailure(AnchorFailure::RustdocAnchorConflict(res))) => Some(res),
906 Err(ErrorKind::AnchorFailure(AnchorFailure::MultipleAnchors)) => None,
912 /// Look to see if a resolved item has an associated item named `item_name`.
914 /// Given `[std::io::Error::source]`, where `source` is unresolved, this would
915 /// find `std::error::Error::source` and return
916 /// `<io::Error as error::Error>::source`.
917 fn resolve_associated_trait_item<'a>(
922 cx: &mut DocContext<'a>,
923 ) -> Option<ty::AssocItem> {
924 // FIXME: this should also consider blanket impls (`impl<T> X for T`). Unfortunately
925 // `get_auto_trait_and_blanket_impls` is broken because the caching behavior is wrong. In the
926 // meantime, just don't look for these blanket impls.
928 // Next consider explicit impls: `impl MyTrait for MyType`
929 // Give precedence to inherent impls.
930 let traits = trait_impls_for(cx, ty, module);
931 debug!("considering traits {:?}", traits);
932 let mut candidates = traits.iter().filter_map(|&(impl_, trait_)| {
934 .associated_items(trait_)
935 .find_by_name_and_namespace(cx.tcx, Ident::with_dummy_span(item_name), ns, trait_)
937 trait_assoc_to_impl_assoc_item(cx.tcx, impl_, trait_assoc.def_id)
938 .unwrap_or(trait_assoc)
941 // FIXME(#74563): warn about ambiguity
942 debug!("the candidates were {:?}", candidates.clone().collect::<Vec<_>>());
943 candidates.next().copied()
946 /// Find the associated item in the impl `impl_id` that corresponds to the
947 /// trait associated item `trait_assoc_id`.
949 /// This function returns `None` if no associated item was found in the impl.
950 /// This can occur when the trait associated item has a default value that is
951 /// not overridden in the impl.
953 /// This is just a wrapper around [`TyCtxt::impl_item_implementor_ids()`] and
954 /// [`TyCtxt::associated_item()`] (with some helpful logging added).
955 #[instrument(level = "debug", skip(tcx))]
956 fn trait_assoc_to_impl_assoc_item<'tcx>(
959 trait_assoc_id: DefId,
960 ) -> Option<&'tcx ty::AssocItem> {
961 let trait_to_impl_assoc_map = tcx.impl_item_implementor_ids(impl_id);
962 debug!(?trait_to_impl_assoc_map);
963 let impl_assoc_id = *trait_to_impl_assoc_map.get(&trait_assoc_id)?;
964 debug!(?impl_assoc_id);
965 let impl_assoc = tcx.associated_item(impl_assoc_id);
970 /// Given a type, return all trait impls in scope in `module` for that type.
971 /// Returns a set of pairs of `(impl_id, trait_id)`.
973 /// NOTE: this cannot be a query because more traits could be available when more crates are compiled!
974 /// So it is not stable to serialize cross-crate.
975 #[instrument(level = "debug", skip(cx))]
976 fn trait_impls_for<'a>(
977 cx: &mut DocContext<'a>,
980 ) -> FxHashSet<(DefId, DefId)> {
982 let iter = cx.resolver_caches.traits_in_scope[&module].iter().flat_map(|trait_candidate| {
983 let trait_ = trait_candidate.def_id;
984 trace!("considering explicit impl for trait {:?}", trait_);
986 // Look at each trait implementation to see if it's an impl for `did`
987 tcx.find_map_relevant_impl(trait_, ty, |impl_| {
988 let trait_ref = tcx.impl_trait_ref(impl_).expect("this is not an inherent impl");
989 // Check if these are the same type.
990 let impl_type = trait_ref.self_ty();
992 "comparing type {} with kind {:?} against type {:?}",
997 // Fast path: if this is a primitive simple `==` will work
998 // NOTE: the `match` is necessary; see #92662.
999 // this allows us to ignore generics because the user input
1000 // may not include the generic placeholders
1001 // e.g. this allows us to match Foo (user comment) with Foo<T> (actual type)
1002 let saw_impl = impl_type == ty
1003 || match (impl_type.kind(), ty.kind()) {
1004 (ty::Adt(impl_def, _), ty::Adt(ty_def, _)) => {
1005 debug!("impl def_id: {:?}, ty def_id: {:?}", impl_def.did(), ty_def.did());
1006 impl_def.did() == ty_def.did()
1011 if saw_impl { Some((impl_, trait_)) } else { None }
1017 /// Check for resolve collisions between a trait and its derive.
1019 /// These are common and we should just resolve to the trait in that case.
1020 fn is_derive_trait_collision<T>(ns: &PerNS<Result<(Res, T), ResolutionFailure<'_>>>) -> bool {
1024 type_ns: Ok((Res::Def(DefKind::Trait, _), _)),
1025 macro_ns: Ok((Res::Def(DefKind::Macro(MacroKind::Derive), _), _)),
1031 impl<'a, 'tcx> DocVisitor for LinkCollector<'a, 'tcx> {
1032 fn visit_item(&mut self, item: &Item) {
1034 item.def_id.as_def_id().and_then(|did| find_nearest_parent_module(self.cx.tcx, did));
1035 if parent_node.is_some() {
1036 trace!("got parent node for {:?} {:?}, id {:?}", item.type_(), item.name, item.def_id);
1039 let inner_docs = item.inner_docs(self.cx.tcx);
1041 if item.is_mod() && inner_docs {
1042 self.mod_ids.push(item.def_id.expect_def_id());
1045 // We want to resolve in the lexical scope of the documentation.
1046 // In the presence of re-exports, this is not the same as the module of the item.
1047 // Rather than merging all documentation into one, resolve it one attribute at a time
1048 // so we know which module it came from.
1049 for (parent_module, doc) in item.attrs.collapsed_doc_value_by_module_level() {
1050 debug!("combined_docs={}", doc);
1052 let (krate, parent_node) = if let Some(id) = parent_module {
1053 (id.krate, Some(id))
1055 (item.def_id.krate(), parent_node)
1057 // NOTE: if there are links that start in one crate and end in another, this will not resolve them.
1058 // This is a degenerate case and it's not supported by rustdoc.
1059 for md_link in markdown_links(&doc) {
1060 let link = self.resolve_link(&item, &doc, parent_node, krate, md_link);
1061 if let Some(link) = link {
1062 self.cx.cache.intra_doc_links.entry(item.def_id).or_default().push(link);
1069 self.mod_ids.push(item.def_id.expect_def_id());
1072 self.visit_item_recur(item);
1075 self.visit_item_recur(item)
1080 enum PreprocessingError<'a> {
1081 Anchor(AnchorFailure),
1082 Disambiguator(Range<usize>, String),
1083 Resolution(ResolutionFailure<'a>, String, Option<Disambiguator>),
1086 impl From<AnchorFailure> for PreprocessingError<'_> {
1087 fn from(err: AnchorFailure) -> Self {
1092 struct PreprocessingInfo {
1094 disambiguator: Option<Disambiguator>,
1095 extra_fragment: Option<String>,
1100 /// - `None` if the link should be ignored.
1101 /// - `Some(Err)` if the link should emit an error
1102 /// - `Some(Ok)` if the link is valid
1104 /// `link_buffer` is needed for lifetime reasons; it will always be overwritten and the contents ignored.
1105 fn preprocess_link<'a>(
1106 ori_link: &'a MarkdownLink,
1107 ) -> Option<Result<PreprocessingInfo, PreprocessingError<'a>>> {
1108 // [] is mostly likely not supposed to be a link
1109 if ori_link.link.is_empty() {
1113 // Bail early for real links.
1114 if ori_link.link.contains('/') {
1118 let stripped = ori_link.link.replace('`', "");
1119 let mut parts = stripped.split('#');
1121 let link = parts.next().unwrap();
1122 if link.trim().is_empty() {
1123 // This is an anchor to an element of the current page, nothing to do in here!
1126 let extra_fragment = parts.next();
1127 if parts.next().is_some() {
1128 // A valid link can't have multiple #'s
1129 return Some(Err(AnchorFailure::MultipleAnchors.into()));
1132 // Parse and strip the disambiguator from the link, if present.
1133 let (disambiguator, path_str, link_text) = match Disambiguator::from_str(link) {
1134 Ok(Some((d, path, link_text))) => (Some(d), path.trim(), link_text.trim()),
1135 Ok(None) => (None, link.trim(), link.trim()),
1136 Err((err_msg, relative_range)) => {
1137 // Only report error if we would not have ignored this link. See issue #83859.
1138 if !should_ignore_link_with_disambiguators(link) {
1139 let no_backticks_range = range_between_backticks(ori_link);
1140 let disambiguator_range = (no_backticks_range.start + relative_range.start)
1141 ..(no_backticks_range.start + relative_range.end);
1142 return Some(Err(PreprocessingError::Disambiguator(disambiguator_range, err_msg)));
1149 if should_ignore_link(path_str) {
1153 // Strip generics from the path.
1154 let path_str = if path_str.contains(['<', '>'].as_slice()) {
1155 match strip_generics_from_path(path_str) {
1158 debug!("link has malformed generics: {}", path_str);
1159 return Some(Err(PreprocessingError::Resolution(
1161 path_str.to_owned(),
1170 // Sanity check to make sure we don't have any angle brackets after stripping generics.
1171 assert!(!path_str.contains(['<', '>'].as_slice()));
1173 // The link is not an intra-doc link if it still contains spaces after stripping generics.
1174 if path_str.contains(' ') {
1178 Some(Ok(PreprocessingInfo {
1181 extra_fragment: extra_fragment.map(|frag| frag.to_owned()),
1182 link_text: link_text.to_owned(),
1186 impl LinkCollector<'_, '_> {
1187 /// This is the entry point for resolving an intra-doc link.
1189 /// FIXME(jynelson): this is way too many arguments
1194 parent_node: Option<DefId>,
1196 ori_link: MarkdownLink,
1197 ) -> Option<ItemLink> {
1198 trace!("considering link '{}'", ori_link.link);
1200 let diag_info = DiagnosticInfo {
1203 ori_link: &ori_link.link,
1204 link_range: ori_link.range.clone(),
1207 let PreprocessingInfo { path_str, disambiguator, extra_fragment, link_text } =
1208 match preprocess_link(&ori_link)? {
1212 PreprocessingError::Anchor(err) => anchor_failure(self.cx, diag_info, err),
1213 PreprocessingError::Disambiguator(range, msg) => {
1214 disambiguator_error(self.cx, diag_info, range, &msg)
1216 PreprocessingError::Resolution(err, path_str, disambiguator) => {
1229 let mut path_str = &*path_str;
1231 let inner_docs = item.inner_docs(self.cx.tcx);
1233 // In order to correctly resolve intra-doc links we need to
1234 // pick a base AST node to work from. If the documentation for
1235 // this module came from an inner comment (//!) then we anchor
1236 // our name resolution *inside* the module. If, on the other
1237 // hand it was an outer comment (///) then we anchor the name
1238 // resolution in the parent module on the basis that the names
1239 // used are more likely to be intended to be parent names. For
1240 // this, we set base_node to None for inner comments since
1241 // we've already pushed this node onto the resolution stack but
1242 // for outer comments we explicitly try and resolve against the
1243 // parent_node first.
1245 if item.is_mod() && inner_docs { self.mod_ids.last().copied() } else { parent_node };
1247 let Some(mut module_id) = base_node else {
1249 debug!("attempting to resolve item without parent module: {}", path_str);
1255 smallvec![ResolutionFailure::NoParentItem],
1261 let is_lone_crate = path_str == "crate";
1262 if path_str.starts_with("crate::") || is_lone_crate {
1263 use rustc_span::def_id::CRATE_DEF_INDEX;
1265 // HACK(jynelson): rustc_resolve thinks that `crate` is the crate currently being documented.
1266 // But rustdoc wants it to mean the crate this item was originally present in.
1267 // To work around this, remove it and resolve relative to the crate root instead.
1268 // HACK(jynelson)(2): If we just strip `crate::` then suddenly primitives become ambiguous
1269 // (consider `crate::char`). Instead, change it to `self::`. This works because 'self' is now the crate root.
1270 // FIXME(#78696): This doesn't always work.
1274 resolved_self = format!("self::{}", &path_str["crate::".len()..]);
1275 path_str = &resolved_self;
1277 module_id = DefId { krate, index: CRATE_DEF_INDEX };
1280 let (mut res, fragment) = self.resolve_with_disambiguator_cached(
1282 item_id: item.def_id,
1285 path_str: path_str.to_owned(),
1288 diag_info.clone(), // this struct should really be Copy, but Range is not :(
1289 matches!(ori_link.kind, LinkType::Reference | LinkType::Shortcut),
1292 // Check for a primitive which might conflict with a module
1293 // Report the ambiguity and require that the user specify which one they meant.
1294 // FIXME: could there ever be a primitive not in the type namespace?
1297 None | Some(Disambiguator::Namespace(Namespace::TypeNS) | Disambiguator::Primitive)
1298 ) && !matches!(res, Res::Primitive(_))
1300 if let Some(prim) = resolve_primitive(path_str, TypeNS) {
1302 if matches!(disambiguator, Some(Disambiguator::Primitive)) {
1305 // `[char]` when a `char` module is in scope
1306 let candidates = vec![res, prim];
1307 ambiguity_error(self.cx, diag_info, path_str, candidates);
1314 Res::Primitive(prim) => {
1315 if let Some(UrlFragment::Item(ItemFragment(_, id))) = fragment {
1316 // We're actually resolving an associated item of a primitive, so we need to
1317 // verify the disambiguator (if any) matches the type of the associated item.
1318 // This case should really follow the same flow as the `Res::Def` branch below,
1319 // but attempting to add a call to `clean::register_res` causes an ICE. @jyn514
1320 // thinks `register_res` is only needed for cross-crate re-exports, but Rust
1321 // doesn't allow statements like `use str::trim;`, making this a (hopefully)
1322 // valid omission. See https://github.com/rust-lang/rust/pull/80660#discussion_r551585677
1323 // for discussion on the matter.
1324 let kind = self.cx.tcx.def_kind(id);
1325 self.verify_disambiguator(
1335 // FIXME: it would be nice to check that the feature gate was enabled in the original crate, not just ignore it altogether.
1336 // However I'm not sure how to check that across crates.
1337 if prim == PrimitiveType::RawPointer
1338 && item.def_id.is_local()
1339 && !self.cx.tcx.features().intra_doc_pointers
1341 self.report_rawptr_assoc_feature_gate(dox, &ori_link, item);
1344 match disambiguator {
1345 Some(Disambiguator::Primitive | Disambiguator::Namespace(_)) | None => {}
1347 self.report_disambiguator_mismatch(
1348 path_str, &ori_link, other, res, &diag_info,
1356 link: ori_link.link,
1358 did: res.def_id(self.cx.tcx),
1362 Res::Def(kind, id) => {
1363 let (kind_for_dis, id_for_dis) =
1364 if let Some(UrlFragment::Item(ItemFragment(_, id))) = fragment {
1365 (self.cx.tcx.def_kind(id), id)
1369 self.verify_disambiguator(
1378 let id = clean::register_res(self.cx, rustc_hir::def::Res::Def(kind, id));
1379 Some(ItemLink { link: ori_link.link, link_text, did: id, fragment })
1384 fn verify_disambiguator(
1387 ori_link: &MarkdownLink,
1390 disambiguator: Option<Disambiguator>,
1392 diag_info: &DiagnosticInfo<'_>,
1394 debug!("intra-doc link to {} resolved to {:?}", path_str, (kind, id));
1396 // Disallow e.g. linking to enums with `struct@`
1397 debug!("saw kind {:?} with disambiguator {:?}", kind, disambiguator);
1398 match (kind, disambiguator) {
1399 | (DefKind::Const | DefKind::ConstParam | DefKind::AssocConst | DefKind::AnonConst, Some(Disambiguator::Kind(DefKind::Const)))
1400 // NOTE: this allows 'method' to mean both normal functions and associated functions
1401 // This can't cause ambiguity because both are in the same namespace.
1402 | (DefKind::Fn | DefKind::AssocFn, Some(Disambiguator::Kind(DefKind::Fn)))
1403 // These are namespaces; allow anything in the namespace to match
1404 | (_, Some(Disambiguator::Namespace(_)))
1405 // If no disambiguator given, allow anything
1407 // All of these are valid, so do nothing
1409 (actual, Some(Disambiguator::Kind(expected))) if actual == expected => {}
1410 (_, Some(specified @ Disambiguator::Kind(_) | specified @ Disambiguator::Primitive)) => {
1411 self.report_disambiguator_mismatch(path_str,ori_link,specified, Res::Def(kind, id),diag_info);
1416 // item can be non-local e.g. when using #[doc(primitive = "pointer")]
1417 if let Some((src_id, dst_id)) = id
1419 // The `expect_def_id()` should be okay because `local_def_id_to_hir_id`
1420 // would presumably panic if a fake `DefIndex` were passed.
1421 .and_then(|dst_id| {
1422 item.def_id.expect_def_id().as_local().map(|src_id| (src_id, dst_id))
1425 if self.cx.tcx.privacy_access_levels(()).is_exported(src_id)
1426 && !self.cx.tcx.privacy_access_levels(()).is_exported(dst_id)
1428 privacy_error(self.cx, diag_info, path_str);
1435 fn report_disambiguator_mismatch(
1438 ori_link: &MarkdownLink,
1439 specified: Disambiguator,
1441 diag_info: &DiagnosticInfo<'_>,
1443 // The resolved item did not match the disambiguator; give a better error than 'not found'
1444 let msg = format!("incompatible link kind for `{}`", path_str);
1445 let callback = |diag: &mut Diagnostic, sp: Option<rustc_span::Span>| {
1447 "this link resolved to {} {}, which is not {} {}",
1450 specified.article(),
1453 if let Some(sp) = sp {
1454 diag.span_label(sp, ¬e);
1458 suggest_disambiguator(resolved, diag, path_str, &ori_link.link, sp);
1460 report_diagnostic(self.cx.tcx, BROKEN_INTRA_DOC_LINKS, &msg, &diag_info, callback);
1463 fn report_rawptr_assoc_feature_gate(&self, dox: &str, ori_link: &MarkdownLink, item: &Item) {
1465 super::source_span_for_markdown_range(self.cx.tcx, dox, &ori_link.range, &item.attrs)
1466 .unwrap_or_else(|| item.attr_span(self.cx.tcx));
1467 rustc_session::parse::feature_err(
1468 &self.cx.tcx.sess.parse_sess,
1469 sym::intra_doc_pointers,
1471 "linking to associated items of raw pointers is experimental",
1473 .note("rustdoc does not allow disambiguating between `*const` and `*mut`, and pointers are unstable until it does")
1477 fn resolve_with_disambiguator_cached(
1479 key: ResolutionInfo,
1480 diag: DiagnosticInfo<'_>,
1481 cache_resolution_failure: bool,
1482 ) -> Option<(Res, Option<UrlFragment>)> {
1483 if let Some(ref cached) = self.visited_links.get(&key) {
1486 return Some(cached.res.clone());
1488 None if cache_resolution_failure => return None,
1490 // Although we hit the cache and found a resolution error, this link isn't
1491 // supposed to cache those. Run link resolution again to emit the expected
1492 // resolution error.
1497 let res = self.resolve_with_disambiguator(&key, diag);
1499 // Cache only if resolved successfully - don't silence duplicate errors
1500 if let Some(res) = res {
1501 // Store result for the actual namespace
1502 self.visited_links.insert(key, Some(CachedLink { res: res.clone() }));
1506 if cache_resolution_failure {
1507 // For reference-style links we only want to report one resolution error
1508 // so let's cache them as well.
1509 self.visited_links.insert(key, None);
1516 /// After parsing the disambiguator, resolve the main part of the link.
1517 // FIXME(jynelson): wow this is just so much
1518 fn resolve_with_disambiguator(
1520 key: &ResolutionInfo,
1521 diag: DiagnosticInfo<'_>,
1522 ) -> Option<(Res, Option<UrlFragment>)> {
1523 let disambiguator = key.dis;
1524 let path_str = &key.path_str;
1525 let item_id = key.item_id;
1526 let base_node = key.module_id;
1527 let extra_fragment = &key.extra_fragment;
1529 match disambiguator.map(Disambiguator::ns) {
1530 Some(expected_ns @ (ValueNS | TypeNS)) => {
1531 match self.resolve(path_str, expected_ns, item_id, base_node, extra_fragment) {
1532 Ok(res) => Some(res),
1533 Err(ErrorKind::Resolve(box mut kind)) => {
1534 // We only looked in one namespace. Try to give a better error if possible.
1535 if kind.full_res().is_none() {
1536 let other_ns = if expected_ns == ValueNS { TypeNS } else { ValueNS };
1537 // FIXME: really it should be `resolution_failure` that does this, not `resolve_with_disambiguator`
1538 // See https://github.com/rust-lang/rust/pull/76955#discussion_r493953382 for a good approach
1539 for new_ns in [other_ns, MacroNS] {
1540 if let Some(res) = self.check_full_res(
1547 kind = ResolutionFailure::WrongNamespace { res, expected_ns };
1552 resolution_failure(self, diag, path_str, disambiguator, smallvec![kind]);
1553 // This could just be a normal link or a broken link
1554 // we could potentially check if something is
1555 // "intra-doc-link-like" and warn in that case.
1558 Err(ErrorKind::AnchorFailure(msg)) => {
1559 anchor_failure(self.cx, diag, msg);
1566 let mut candidates = PerNS {
1568 .resolve_macro(path_str, item_id, base_node)
1569 .map(|res| (res, extra_fragment.clone().map(UrlFragment::UserWritten))),
1570 type_ns: match self.resolve(
1578 debug!("got res in TypeNS: {:?}", res);
1581 Err(ErrorKind::AnchorFailure(msg)) => {
1582 anchor_failure(self.cx, diag, msg);
1585 Err(ErrorKind::Resolve(box kind)) => Err(kind),
1587 value_ns: match self.resolve(
1595 Err(ErrorKind::AnchorFailure(msg)) => {
1596 anchor_failure(self.cx, diag, msg);
1599 Err(ErrorKind::Resolve(box kind)) => Err(kind),
1601 .and_then(|(res, fragment)| {
1602 // Constructors are picked up in the type namespace.
1604 Res::Def(DefKind::Ctor(..), _) => {
1605 Err(ResolutionFailure::WrongNamespace { res, expected_ns: TypeNS })
1608 match (fragment, extra_fragment.clone()) {
1609 (Some(fragment), Some(_)) => {
1610 // Shouldn't happen but who knows?
1611 Ok((res, Some(fragment)))
1613 (fragment, None) => Ok((res, fragment)),
1614 (None, fragment) => {
1615 Ok((res, fragment.map(UrlFragment::UserWritten)))
1623 let len = candidates.iter().filter(|res| res.is_ok()).count();
1631 candidates.into_iter().filter_map(|res| res.err()).collect(),
1633 // this could just be a normal link
1638 Some(candidates.into_iter().find_map(|res| res.ok()).unwrap())
1639 } else if len == 2 && is_derive_trait_collision(&candidates) {
1640 Some(candidates.type_ns.unwrap())
1642 if is_derive_trait_collision(&candidates) {
1643 candidates.macro_ns = Err(ResolutionFailure::Dummy);
1645 // If we're reporting an ambiguity, don't mention the namespaces that failed
1646 let candidates = candidates.map(|candidate| candidate.ok().map(|(res, _)| res));
1647 ambiguity_error(self.cx, diag, path_str, candidates.present_items().collect());
1652 match self.resolve_macro(path_str, item_id, base_node) {
1653 Ok(res) => Some((res, extra_fragment.clone().map(UrlFragment::UserWritten))),
1655 // `resolve_macro` only looks in the macro namespace. Try to give a better error if possible.
1656 for ns in [TypeNS, ValueNS] {
1657 if let Some(res) = self.check_full_res(
1665 ResolutionFailure::WrongNamespace { res, expected_ns: MacroNS };
1669 resolution_failure(self, diag, path_str, disambiguator, smallvec![kind]);
1678 /// Get the section of a link between the backticks,
1679 /// or the whole link if there aren't any backticks.
1687 fn range_between_backticks(ori_link: &MarkdownLink) -> Range<usize> {
1688 let after_first_backtick_group = ori_link.link.bytes().position(|b| b != b'`').unwrap_or(0);
1689 let before_second_backtick_group = ori_link
1692 .skip(after_first_backtick_group)
1693 .position(|b| b == b'`')
1694 .unwrap_or(ori_link.link.len());
1695 (ori_link.range.start + after_first_backtick_group)
1696 ..(ori_link.range.start + before_second_backtick_group)
1699 /// Returns true if we should ignore `link` due to it being unlikely
1700 /// that it is an intra-doc link. `link` should still have disambiguators
1701 /// if there were any.
1703 /// The difference between this and [`should_ignore_link()`] is that this
1704 /// check should only be used on links that still have disambiguators.
1705 fn should_ignore_link_with_disambiguators(link: &str) -> bool {
1706 link.contains(|ch: char| !(ch.is_alphanumeric() || ":_<>, !*&;@()".contains(ch)))
1709 /// Returns true if we should ignore `path_str` due to it being unlikely
1710 /// that it is an intra-doc link.
1711 fn should_ignore_link(path_str: &str) -> bool {
1712 path_str.contains(|ch: char| !(ch.is_alphanumeric() || ":_<>, !*&;".contains(ch)))
1715 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
1716 /// Disambiguators for a link.
1717 enum Disambiguator {
1720 /// This is buggy, see <https://github.com/rust-lang/rust/pull/77875#discussion_r503583103>
1722 /// `struct@` or `f()`
1725 Namespace(Namespace),
1728 impl Disambiguator {
1729 /// Given a link, parse and return `(disambiguator, path_str, link_text)`.
1731 /// This returns `Ok(Some(...))` if a disambiguator was found,
1732 /// `Ok(None)` if no disambiguator was found, or `Err(...)`
1733 /// if there was a problem with the disambiguator.
1734 fn from_str(link: &str) -> Result<Option<(Self, &str, &str)>, (String, Range<usize>)> {
1735 use Disambiguator::{Kind, Namespace as NS, Primitive};
1737 if let Some(idx) = link.find('@') {
1738 let (prefix, rest) = link.split_at(idx);
1739 let d = match prefix {
1740 "struct" => Kind(DefKind::Struct),
1741 "enum" => Kind(DefKind::Enum),
1742 "trait" => Kind(DefKind::Trait),
1743 "union" => Kind(DefKind::Union),
1744 "module" | "mod" => Kind(DefKind::Mod),
1745 "const" | "constant" => Kind(DefKind::Const),
1746 "static" => Kind(DefKind::Static),
1747 "function" | "fn" | "method" => Kind(DefKind::Fn),
1748 "derive" => Kind(DefKind::Macro(MacroKind::Derive)),
1749 "type" => NS(Namespace::TypeNS),
1750 "value" => NS(Namespace::ValueNS),
1751 "macro" => NS(Namespace::MacroNS),
1752 "prim" | "primitive" => Primitive,
1753 _ => return Err((format!("unknown disambiguator `{}`", prefix), 0..idx)),
1755 Ok(Some((d, &rest[1..], &rest[1..])))
1758 ("!()", DefKind::Macro(MacroKind::Bang)),
1759 ("!{}", DefKind::Macro(MacroKind::Bang)),
1760 ("![]", DefKind::Macro(MacroKind::Bang)),
1761 ("()", DefKind::Fn),
1762 ("!", DefKind::Macro(MacroKind::Bang)),
1764 for (suffix, kind) in suffixes {
1765 if let Some(path_str) = link.strip_suffix(suffix) {
1766 // Avoid turning `!` or `()` into an empty string
1767 if !path_str.is_empty() {
1768 return Ok(Some((Kind(kind), path_str, link)));
1776 fn ns(self) -> Namespace {
1778 Self::Namespace(n) => n,
1780 k.ns().expect("only DefKinds with a valid namespace can be disambiguators")
1782 Self::Primitive => TypeNS,
1786 fn article(self) -> &'static str {
1788 Self::Namespace(_) => panic!("article() doesn't make sense for namespaces"),
1789 Self::Kind(k) => k.article(),
1790 Self::Primitive => "a",
1794 fn descr(self) -> &'static str {
1796 Self::Namespace(n) => n.descr(),
1797 // HACK(jynelson): the source of `DefKind::descr` only uses the DefId for
1798 // printing "module" vs "crate" so using the wrong ID is not a huge problem
1799 Self::Kind(k) => k.descr(CRATE_DEF_ID.to_def_id()),
1800 Self::Primitive => "builtin type",
1805 /// A suggestion to show in a diagnostic.
1808 Prefix(&'static str),
1813 /// `foo` without any disambiguator
1814 RemoveDisambiguator,
1818 fn descr(&self) -> Cow<'static, str> {
1820 Self::Prefix(x) => format!("prefix with `{}@`", x).into(),
1821 Self::Function => "add parentheses".into(),
1822 Self::Macro => "add an exclamation mark".into(),
1823 Self::RemoveDisambiguator => "remove the disambiguator".into(),
1827 fn as_help(&self, path_str: &str) -> String {
1828 // FIXME: if this is an implied shortcut link, it's bad style to suggest `@`
1830 Self::Prefix(prefix) => format!("{}@{}", prefix, path_str),
1831 Self::Function => format!("{}()", path_str),
1832 Self::Macro => format!("{}!", path_str),
1833 Self::RemoveDisambiguator => path_str.into(),
1841 sp: rustc_span::Span,
1842 ) -> Vec<(rustc_span::Span, String)> {
1843 let inner_sp = match ori_link.find('(') {
1844 Some(index) => sp.with_hi(sp.lo() + BytePos(index as _)),
1847 let inner_sp = match ori_link.find('!') {
1848 Some(index) => inner_sp.with_hi(inner_sp.lo() + BytePos(index as _)),
1851 let inner_sp = match ori_link.find('@') {
1852 Some(index) => inner_sp.with_lo(inner_sp.lo() + BytePos(index as u32 + 1)),
1856 Self::Prefix(prefix) => {
1857 // FIXME: if this is an implied shortcut link, it's bad style to suggest `@`
1858 let mut sugg = vec![(sp.with_hi(inner_sp.lo()), format!("{}@", prefix))];
1859 if sp.hi() != inner_sp.hi() {
1860 sugg.push((inner_sp.shrink_to_hi().with_hi(sp.hi()), String::new()));
1865 let mut sugg = vec![(inner_sp.shrink_to_hi().with_hi(sp.hi()), "()".to_string())];
1866 if sp.lo() != inner_sp.lo() {
1867 sugg.push((inner_sp.shrink_to_lo().with_lo(sp.lo()), String::new()));
1872 let mut sugg = vec![(inner_sp.shrink_to_hi(), "!".to_string())];
1873 if sp.lo() != inner_sp.lo() {
1874 sugg.push((inner_sp.shrink_to_lo().with_lo(sp.lo()), String::new()));
1878 Self::RemoveDisambiguator => vec![(sp, path_str.into())],
1883 /// Reports a diagnostic for an intra-doc link.
1885 /// If no link range is provided, or the source span of the link cannot be determined, the span of
1886 /// the entire documentation block is used for the lint. If a range is provided but the span
1887 /// calculation fails, a note is added to the diagnostic pointing to the link in the markdown.
1889 /// The `decorate` callback is invoked in all cases to allow further customization of the
1890 /// diagnostic before emission. If the span of the link was able to be determined, the second
1891 /// parameter of the callback will contain it, and the primary span of the diagnostic will be set
1893 fn report_diagnostic(
1895 lint: &'static Lint,
1897 DiagnosticInfo { item, ori_link: _, dox, link_range }: &DiagnosticInfo<'_>,
1898 decorate: impl FnOnce(&mut Diagnostic, Option<rustc_span::Span>),
1900 let Some(hir_id) = DocContext::as_local_hir_id(tcx, item.def_id)
1902 // If non-local, no need to check anything.
1903 info!("ignoring warning from parent crate: {}", msg);
1907 let sp = item.attr_span(tcx);
1909 tcx.struct_span_lint_hir(lint, hir_id, sp, |lint| {
1910 let mut diag = lint.build(msg);
1913 super::source_span_for_markdown_range(tcx, dox, link_range, &item.attrs).map(|sp| {
1914 if dox.as_bytes().get(link_range.start) == Some(&b'`')
1915 && dox.as_bytes().get(link_range.end - 1) == Some(&b'`')
1917 sp.with_lo(sp.lo() + BytePos(1)).with_hi(sp.hi() - BytePos(1))
1923 if let Some(sp) = span {
1926 // blah blah blah\nblah\nblah [blah] blah blah\nblah blah
1929 // last_new_line_offset
1930 let last_new_line_offset = dox[..link_range.start].rfind('\n').map_or(0, |n| n + 1);
1931 let line = dox[last_new_line_offset..].lines().next().unwrap_or("");
1933 // Print the line containing the `link_range` and manually mark it with '^'s.
1935 "the link appears in this line:\n\n{line}\n\
1936 {indicator: <before$}{indicator:^<found$}",
1939 before = link_range.start - last_new_line_offset,
1940 found = link_range.len(),
1944 decorate(&mut diag, span);
1950 /// Reports a link that failed to resolve.
1952 /// This also tries to resolve any intermediate path segments that weren't
1953 /// handled earlier. For example, if passed `Item::Crate(std)` and `path_str`
1954 /// `std::io::Error::x`, this will resolve `std::io::Error`.
1955 fn resolution_failure(
1956 collector: &mut LinkCollector<'_, '_>,
1957 diag_info: DiagnosticInfo<'_>,
1959 disambiguator: Option<Disambiguator>,
1960 kinds: SmallVec<[ResolutionFailure<'_>; 3]>,
1962 let tcx = collector.cx.tcx;
1965 BROKEN_INTRA_DOC_LINKS,
1966 &format!("unresolved link to `{}`", path_str),
1969 let item = |res: Res| format!("the {} `{}`", res.descr(), res.name(tcx),);
1970 let assoc_item_not_allowed = |res: Res| {
1971 let name = res.name(tcx);
1973 "`{}` is {} {}, not a module or type, and cannot have associated items",
1979 // ignore duplicates
1980 let mut variants_seen = SmallVec::<[_; 3]>::new();
1981 for mut failure in kinds {
1982 let variant = std::mem::discriminant(&failure);
1983 if variants_seen.contains(&variant) {
1986 variants_seen.push(variant);
1988 if let ResolutionFailure::NotResolved {
1997 let item_id = *item_id;
1998 let module_id = *module_id;
1999 // FIXME(jynelson): this might conflict with my `Self` fix in #76467
2000 // FIXME: maybe use itertools `collect_tuple` instead?
2001 fn split(path: &str) -> Option<(&str, &str)> {
2002 let mut splitter = path.rsplitn(2, "::");
2003 splitter.next().and_then(|right| splitter.next().map(|left| (left, right)))
2006 // Check if _any_ parent of the path gets resolved.
2007 // If so, report it and say the first which failed; if not, say the first path segment didn't resolve.
2008 let mut name = path_str;
2010 let Some((start, end)) = split(name) else {
2011 // avoid bug that marked [Quux::Z] as missing Z, not Quux
2012 if partial_res.is_none() {
2013 *unresolved = name.into();
2018 for ns in [TypeNS, ValueNS, MacroNS] {
2020 collector.check_full_res(ns, start, item_id, module_id, &None)
2022 debug!("found partial_res={:?}", res);
2023 *partial_res = Some(res);
2024 *unresolved = end.into();
2028 *unresolved = end.into();
2031 let last_found_module = match *partial_res {
2032 Some(Res::Def(DefKind::Mod, id)) => Some(id),
2033 None => Some(module_id),
2036 // See if this was a module: `[path]` or `[std::io::nope]`
2037 if let Some(module) = last_found_module {
2038 let note = if partial_res.is_some() {
2039 // Part of the link resolved; e.g. `std::io::nonexistent`
2040 let module_name = tcx.item_name(module);
2041 format!("no item named `{}` in module `{}`", unresolved, module_name)
2043 // None of the link resolved; e.g. `Notimported`
2044 format!("no item named `{}` in scope", unresolved)
2046 if let Some(span) = sp {
2047 diag.span_label(span, ¬e);
2052 // If the link has `::` in it, assume it was meant to be an intra-doc link.
2053 // Otherwise, the `[]` might be unrelated.
2054 // FIXME: don't show this for autolinks (`<>`), `()` style links, or reference links
2055 if !path_str.contains("::") {
2056 diag.help(r#"to escape `[` and `]` characters, add '\' before them like `\[` or `\]`"#);
2062 // Otherwise, it must be an associated item or variant
2063 let res = partial_res.expect("None case was handled by `last_found_module`");
2064 let name = res.name(tcx);
2065 let kind = match res {
2066 Res::Def(kind, _) => Some(kind),
2067 Res::Primitive(_) => None,
2069 let path_description = if let Some(kind) = kind {
2071 Mod | ForeignMod => "inner item",
2072 Struct => "field or associated item",
2073 Enum | Union => "variant or associated item",
2091 let note = assoc_item_not_allowed(res);
2092 if let Some(span) = sp {
2093 diag.span_label(span, ¬e);
2099 Trait | TyAlias | ForeignTy | OpaqueTy | TraitAlias | TyParam
2100 | Static => "associated item",
2101 Impl | GlobalAsm => unreachable!("not a path"),
2107 "the {} `{}` has no {} named `{}`",
2110 disambiguator.map_or(path_description, |d| d.descr()),
2113 if let Some(span) = sp {
2114 diag.span_label(span, ¬e);
2121 let note = match failure {
2122 ResolutionFailure::NotResolved { .. } => unreachable!("handled above"),
2123 ResolutionFailure::Dummy => continue,
2124 ResolutionFailure::WrongNamespace { res, expected_ns } => {
2125 suggest_disambiguator(res, diag, path_str, diag_info.ori_link, sp);
2128 "this link resolves to {}, which is not in the {} namespace",
2133 ResolutionFailure::NoParentItem => {
2134 // FIXME(eddyb) this doesn't belong here, whatever made
2135 // the `ResolutionFailure::NoParentItem` should emit an
2136 // immediate or delayed `span_bug` about the issue.
2137 tcx.sess.delay_span_bug(
2138 sp.unwrap_or(DUMMY_SP),
2139 "intra-doc link missing parent item",
2142 "BUG: all intra-doc links should have a parent item".to_owned()
2144 ResolutionFailure::MalformedGenerics(variant) => match variant {
2145 MalformedGenerics::UnbalancedAngleBrackets => {
2146 String::from("unbalanced angle brackets")
2148 MalformedGenerics::MissingType => {
2149 String::from("missing type for generic parameters")
2151 MalformedGenerics::HasFullyQualifiedSyntax => {
2152 diag.note("see https://github.com/rust-lang/rust/issues/74563 for more information");
2153 String::from("fully-qualified syntax is unsupported")
2155 MalformedGenerics::InvalidPathSeparator => {
2156 String::from("has invalid path separator")
2158 MalformedGenerics::TooManyAngleBrackets => {
2159 String::from("too many angle brackets")
2161 MalformedGenerics::EmptyAngleBrackets => {
2162 String::from("empty angle brackets")
2166 if let Some(span) = sp {
2167 diag.span_label(span, ¬e);
2176 /// Report an anchor failure.
2177 fn anchor_failure(cx: &DocContext<'_>, diag_info: DiagnosticInfo<'_>, failure: AnchorFailure) {
2178 let (msg, anchor_idx) = match failure {
2179 AnchorFailure::MultipleAnchors => {
2180 (format!("`{}` contains multiple anchors", diag_info.ori_link), 1)
2182 AnchorFailure::RustdocAnchorConflict(res) => (
2184 "`{}` contains an anchor, but links to {kind}s are already anchored",
2192 report_diagnostic(cx.tcx, BROKEN_INTRA_DOC_LINKS, &msg, &diag_info, |diag, sp| {
2193 if let Some(mut sp) = sp {
2194 if let Some((fragment_offset, _)) =
2195 diag_info.ori_link.char_indices().filter(|(_, x)| *x == '#').nth(anchor_idx)
2197 sp = sp.with_lo(sp.lo() + BytePos(fragment_offset as _));
2199 diag.span_label(sp, "invalid anchor");
2201 if let AnchorFailure::RustdocAnchorConflict(Res::Primitive(_)) = failure {
2202 if let Some(sp) = sp {
2203 span_bug!(sp, "anchors should be allowed now");
2205 bug!("anchors should be allowed now");
2211 /// Report an error in the link disambiguator.
2212 fn disambiguator_error(
2213 cx: &DocContext<'_>,
2214 mut diag_info: DiagnosticInfo<'_>,
2215 disambiguator_range: Range<usize>,
2218 diag_info.link_range = disambiguator_range;
2219 report_diagnostic(cx.tcx, BROKEN_INTRA_DOC_LINKS, msg, &diag_info, |diag, _sp| {
2221 "see {}/rustdoc/linking-to-items-by-name.html#namespaces-and-disambiguators for more info about disambiguators",
2222 crate::DOC_RUST_LANG_ORG_CHANNEL
2228 /// Report an ambiguity error, where there were multiple possible resolutions.
2230 cx: &DocContext<'_>,
2231 diag_info: DiagnosticInfo<'_>,
2233 candidates: Vec<Res>,
2235 let mut msg = format!("`{}` is ", path_str);
2237 match candidates.as_slice() {
2238 [first_def, second_def] => {
2240 "both {} {} and {} {}",
2241 first_def.article(),
2243 second_def.article(),
2248 let mut candidates = candidates.iter().peekable();
2249 while let Some(res) = candidates.next() {
2250 if candidates.peek().is_some() {
2251 msg += &format!("{} {}, ", res.article(), res.descr());
2253 msg += &format!("and {} {}", res.article(), res.descr());
2259 report_diagnostic(cx.tcx, BROKEN_INTRA_DOC_LINKS, &msg, &diag_info, |diag, sp| {
2260 if let Some(sp) = sp {
2261 diag.span_label(sp, "ambiguous link");
2263 diag.note("ambiguous link");
2266 for res in candidates {
2267 suggest_disambiguator(res, diag, path_str, diag_info.ori_link, sp);
2272 /// In case of an ambiguity or mismatched disambiguator, suggest the correct
2274 fn suggest_disambiguator(
2276 diag: &mut Diagnostic,
2279 sp: Option<rustc_span::Span>,
2281 let suggestion = res.disambiguator_suggestion();
2282 let help = format!("to link to the {}, {}", res.descr(), suggestion.descr());
2284 if let Some(sp) = sp {
2285 let mut spans = suggestion.as_help_span(path_str, ori_link, sp);
2286 if spans.len() > 1 {
2287 diag.multipart_suggestion(&help, spans, Applicability::MaybeIncorrect);
2289 let (sp, suggestion_text) = spans.pop().unwrap();
2290 diag.span_suggestion_verbose(sp, &help, suggestion_text, Applicability::MaybeIncorrect);
2293 diag.help(&format!("{}: {}", help, suggestion.as_help(path_str)));
2297 /// Report a link from a public item to a private one.
2298 fn privacy_error(cx: &DocContext<'_>, diag_info: &DiagnosticInfo<'_>, path_str: &str) {
2300 let item_name = match diag_info.item.name {
2305 None => "<unknown>",
2308 format!("public documentation for `{}` links to private item `{}`", item_name, path_str);
2310 report_diagnostic(cx.tcx, PRIVATE_INTRA_DOC_LINKS, &msg, diag_info, |diag, sp| {
2311 if let Some(sp) = sp {
2312 diag.span_label(sp, "this item is private");
2315 let note_msg = if cx.render_options.document_private {
2316 "this link resolves only because you passed `--document-private-items`, but will break without"
2318 "this link will resolve properly if you pass `--document-private-items`"
2320 diag.note(note_msg);
2324 /// Given an enum variant's res, return the res of its enum and the associated fragment.
2326 cx: &DocContext<'_>,
2328 ) -> Result<(Res, Option<ItemFragment>), ErrorKind<'static>> {
2330 .parent(res.def_id(cx.tcx))
2332 let parent_def = Res::Def(DefKind::Enum, parent);
2333 let variant = cx.tcx.expect_variant_res(res.as_hir_res().unwrap());
2334 (parent_def, Some(ItemFragment(FragmentKind::Variant, variant.def_id)))
2336 .ok_or_else(|| ResolutionFailure::NoParentItem.into())
2339 /// Resolve a primitive type or value.
2340 fn resolve_primitive(path_str: &str, ns: Namespace) -> Option<Res> {
2344 use PrimitiveType::*;
2345 let prim = match path_str {
2361 "bool" | "true" | "false" => Bool,
2362 "str" | "&str" => Str,
2363 // See #80181 for why these don't have symbols associated.
2368 "pointer" | "*const" | "*mut" => RawPointer,
2369 "reference" | "&" | "&mut" => Reference,
2371 "never" | "!" => Never,
2374 debug!("resolved primitives {:?}", prim);
2375 Some(Res::Primitive(prim))
2378 fn strip_generics_from_path(path_str: &str) -> Result<String, ResolutionFailure<'static>> {
2379 let mut stripped_segments = vec![];
2380 let mut path = path_str.chars().peekable();
2381 let mut segment = Vec::new();
2383 while let Some(chr) = path.next() {
2386 if path.next_if_eq(&':').is_some() {
2387 let stripped_segment =
2388 strip_generics_from_path_segment(mem::take(&mut segment))?;
2389 if !stripped_segment.is_empty() {
2390 stripped_segments.push(stripped_segment);
2393 return Err(ResolutionFailure::MalformedGenerics(
2394 MalformedGenerics::InvalidPathSeparator,
2403 return Err(ResolutionFailure::MalformedGenerics(
2404 MalformedGenerics::TooManyAngleBrackets,
2408 return Err(ResolutionFailure::MalformedGenerics(
2409 MalformedGenerics::EmptyAngleBrackets,
2415 while let Some(chr) = path.next_if(|c| *c != '>') {
2422 _ => segment.push(chr),
2424 trace!("raw segment: {:?}", segment);
2427 if !segment.is_empty() {
2428 let stripped_segment = strip_generics_from_path_segment(segment)?;
2429 if !stripped_segment.is_empty() {
2430 stripped_segments.push(stripped_segment);
2434 debug!("path_str: {:?}\nstripped segments: {:?}", path_str, &stripped_segments);
2436 let stripped_path = stripped_segments.join("::");
2438 if !stripped_path.is_empty() {
2441 Err(ResolutionFailure::MalformedGenerics(MalformedGenerics::MissingType))
2445 fn strip_generics_from_path_segment(
2447 ) -> Result<String, ResolutionFailure<'static>> {
2448 let mut stripped_segment = String::new();
2449 let mut param_depth = 0;
2451 let mut latest_generics_chunk = String::new();
2456 latest_generics_chunk.clear();
2457 } else if c == '>' {
2459 if latest_generics_chunk.contains(" as ") {
2460 // The segment tries to use fully-qualified syntax, which is currently unsupported.
2461 // Give a helpful error message instead of completely ignoring the angle brackets.
2462 return Err(ResolutionFailure::MalformedGenerics(
2463 MalformedGenerics::HasFullyQualifiedSyntax,
2467 if param_depth == 0 {
2468 stripped_segment.push(c);
2470 latest_generics_chunk.push(c);
2475 if param_depth == 0 {
2476 Ok(stripped_segment)
2478 // The segment has unbalanced angle brackets, e.g. `Vec<T` or `Vec<T>>`
2479 Err(ResolutionFailure::MalformedGenerics(MalformedGenerics::UnbalancedAngleBrackets))