1 //! This module contains the "cleaned" pieces of the AST, and the functions
8 mod render_macro_matchers;
14 use rustc_attr as attr;
15 use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap, FxIndexSet, IndexEntry};
17 use rustc_hir::def::{CtorKind, DefKind, Res};
18 use rustc_hir::def_id::{DefId, LOCAL_CRATE};
19 use rustc_hir::PredicateOrigin;
20 use rustc_hir_analysis::hir_ty_to_ty;
21 use rustc_infer::infer::region_constraints::{Constraint, RegionConstraintData};
22 use rustc_middle::middle::resolve_lifetime as rl;
23 use rustc_middle::ty::fold::TypeFolder;
24 use rustc_middle::ty::InternalSubsts;
25 use rustc_middle::ty::TypeVisitable;
26 use rustc_middle::ty::{self, AdtKind, DefIdTree, EarlyBinder, Ty, TyCtxt};
27 use rustc_middle::{bug, span_bug};
28 use rustc_span::hygiene::{AstPass, MacroKind};
29 use rustc_span::symbol::{kw, sym, Ident, Symbol};
30 use rustc_span::{self, ExpnKind};
32 use std::assert_matches::assert_matches;
33 use std::collections::hash_map::Entry;
34 use std::collections::BTreeMap;
35 use std::default::Default;
38 use thin_vec::ThinVec;
40 use crate::core::{self, DocContext, ImplTraitParam};
41 use crate::formats::item_type::ItemType;
42 use crate::visit_ast::Module as DocModule;
46 pub(crate) use self::types::*;
47 pub(crate) use self::utils::{get_auto_trait_and_blanket_impls, krate, register_res};
49 pub(crate) fn clean_doc_module<'tcx>(doc: &DocModule<'tcx>, cx: &mut DocContext<'tcx>) -> Item {
50 let mut items: Vec<Item> = vec![];
51 let mut inserted = FxHashSet::default();
52 items.extend(doc.foreigns.iter().map(|(item, renamed)| {
53 let item = clean_maybe_renamed_foreign_item(cx, item, *renamed);
54 if let Some(name) = item.name && !item.attrs.lists(sym::doc).has_word(sym::hidden) {
55 inserted.insert((item.type_(), name));
59 items.extend(doc.mods.iter().filter_map(|x| {
60 if !inserted.insert((ItemType::Module, x.name)) {
63 let item = clean_doc_module(x, cx);
64 if item.attrs.lists(sym::doc).has_word(sym::hidden) {
65 // Hidden modules are stripped at a later stage.
66 // If a hidden module has the same name as a visible one, we want
67 // to keep both of them around.
68 inserted.remove(&(ItemType::Module, x.name));
73 // Split up imports from all other items.
75 // This covers the case where somebody does an import which should pull in an item,
76 // but there's already an item with the same namespace and same name. Rust gives
77 // priority to the not-imported one, so we should, too.
78 items.extend(doc.items.iter().flat_map(|(item, renamed, import_id)| {
79 // First, lower everything other than imports.
80 if matches!(item.kind, hir::ItemKind::Use(_, hir::UseKind::Glob)) {
83 let v = clean_maybe_renamed_item(cx, item, *renamed, *import_id);
85 if let Some(name) = item.name && !item.attrs.lists(sym::doc).has_word(sym::hidden) {
86 inserted.insert((item.type_(), name));
91 items.extend(doc.items.iter().flat_map(|(item, renamed, _)| {
92 // Now we actually lower the imports, skipping everything else.
93 if let hir::ItemKind::Use(path, hir::UseKind::Glob) = item.kind {
94 let name = renamed.unwrap_or_else(|| cx.tcx.hir().name(item.hir_id()));
95 clean_use_statement(item, name, path, hir::UseKind::Glob, cx, &mut inserted)
97 // skip everything else
102 // determine if we should display the inner contents or
103 // the outer `mod` item for the source code.
105 let span = Span::new({
106 let where_outer = doc.where_outer(cx.tcx);
107 let sm = cx.sess().source_map();
108 let outer = sm.lookup_char_pos(where_outer.lo());
109 let inner = sm.lookup_char_pos(doc.where_inner.lo());
110 if outer.file.start_pos == inner.file.start_pos {
114 // mod foo; (and a separate SourceFile for the contents)
119 Item::from_hir_id_and_parts(doc.id, Some(doc.name), ModuleItem(Module { items, span }), cx)
122 fn clean_generic_bound<'tcx>(
123 bound: &hir::GenericBound<'tcx>,
124 cx: &mut DocContext<'tcx>,
125 ) -> Option<GenericBound> {
127 hir::GenericBound::Outlives(lt) => GenericBound::Outlives(clean_lifetime(lt, cx)),
128 hir::GenericBound::LangItemTrait(lang_item, span, _, generic_args) => {
129 let def_id = cx.tcx.require_lang_item(lang_item, Some(span));
131 let trait_ref = ty::TraitRef::identity(cx.tcx, def_id);
133 let generic_args = clean_generic_args(generic_args, cx);
134 let GenericArgs::AngleBracketed { bindings, .. } = generic_args
136 bug!("clean: parenthesized `GenericBound::LangItemTrait`");
139 let trait_ = clean_trait_ref_with_bindings(cx, trait_ref, bindings);
140 GenericBound::TraitBound(
141 PolyTrait { trait_, generic_params: vec![] },
142 hir::TraitBoundModifier::None,
145 hir::GenericBound::Trait(ref t, modifier) => {
146 // `T: ~const Destruct` is hidden because `T: Destruct` is a no-op.
147 if modifier == hir::TraitBoundModifier::MaybeConst
148 && cx.tcx.lang_items().destruct_trait() == Some(t.trait_ref.trait_def_id().unwrap())
153 GenericBound::TraitBound(clean_poly_trait_ref(t, cx), modifier)
158 pub(crate) fn clean_trait_ref_with_bindings<'tcx>(
159 cx: &mut DocContext<'tcx>,
160 trait_ref: ty::PolyTraitRef<'tcx>,
161 bindings: ThinVec<TypeBinding>,
163 let kind = cx.tcx.def_kind(trait_ref.def_id()).into();
164 if !matches!(kind, ItemType::Trait | ItemType::TraitAlias) {
165 span_bug!(cx.tcx.def_span(trait_ref.def_id()), "`TraitRef` had unexpected kind {:?}", kind);
167 inline::record_extern_fqn(cx, trait_ref.def_id(), kind);
169 external_path(cx, trait_ref.def_id(), true, bindings, trait_ref.map_bound(|tr| tr.substs));
176 fn clean_poly_trait_ref_with_bindings<'tcx>(
177 cx: &mut DocContext<'tcx>,
178 poly_trait_ref: ty::PolyTraitRef<'tcx>,
179 bindings: ThinVec<TypeBinding>,
181 // collect any late bound regions
182 let late_bound_regions: Vec<_> = cx
184 .collect_referenced_late_bound_regions(&poly_trait_ref)
186 .filter_map(|br| match br {
187 ty::BrNamed(_, name) if br.is_named() => Some(GenericParamDef::lifetime(name)),
192 let trait_ = clean_trait_ref_with_bindings(cx, poly_trait_ref, bindings);
193 GenericBound::TraitBound(
194 PolyTrait { trait_, generic_params: late_bound_regions },
195 hir::TraitBoundModifier::None,
199 fn clean_lifetime<'tcx>(lifetime: &hir::Lifetime, cx: &mut DocContext<'tcx>) -> Lifetime {
200 let def = cx.tcx.named_region(lifetime.hir_id);
202 rl::Region::EarlyBound(node_id)
203 | rl::Region::LateBound(_, _, node_id)
204 | rl::Region::Free(_, node_id),
207 if let Some(lt) = cx.substs.get(&node_id).and_then(|p| p.as_lt()).cloned() {
211 Lifetime(lifetime.ident.name)
214 pub(crate) fn clean_const<'tcx>(constant: &hir::ConstArg, cx: &mut DocContext<'tcx>) -> Constant {
215 let def_id = cx.tcx.hir().body_owner_def_id(constant.value.body).to_def_id();
217 type_: clean_middle_ty(ty::Binder::dummy(cx.tcx.type_of(def_id)), cx, Some(def_id)),
218 kind: ConstantKind::Anonymous { body: constant.value.body },
222 pub(crate) fn clean_middle_const<'tcx>(
223 constant: ty::Binder<'tcx, ty::Const<'tcx>>,
224 cx: &mut DocContext<'tcx>,
226 // FIXME: instead of storing the stringified expression, store `self` directly instead.
228 type_: clean_middle_ty(constant.map_bound(|c| c.ty()), cx, None),
229 kind: ConstantKind::TyConst { expr: constant.skip_binder().to_string().into() },
233 pub(crate) fn clean_middle_region<'tcx>(region: ty::Region<'tcx>) -> Option<Lifetime> {
235 ty::ReStatic => Some(Lifetime::statik()),
236 _ if !region.has_name() => None,
237 ty::ReLateBound(_, ty::BoundRegion { kind: ty::BrNamed(_, name), .. }) => {
240 ty::ReEarlyBound(ref data) => Some(Lifetime(data.name)),
244 | ty::RePlaceholder(..)
246 debug!("cannot clean region {:?}", region);
252 fn clean_where_predicate<'tcx>(
253 predicate: &hir::WherePredicate<'tcx>,
254 cx: &mut DocContext<'tcx>,
255 ) -> Option<WherePredicate> {
256 if !predicate.in_where_clause() {
259 Some(match *predicate {
260 hir::WherePredicate::BoundPredicate(ref wbp) => {
261 let bound_params = wbp
262 .bound_generic_params
265 // Higher-ranked params must be lifetimes.
266 // Higher-ranked lifetimes can't have bounds.
269 hir::GenericParam { kind: hir::GenericParamKind::Lifetime { .. }, .. }
271 Lifetime(param.name.ident().name)
274 WherePredicate::BoundPredicate {
275 ty: clean_ty(wbp.bounded_ty, cx),
276 bounds: wbp.bounds.iter().filter_map(|x| clean_generic_bound(x, cx)).collect(),
281 hir::WherePredicate::RegionPredicate(ref wrp) => WherePredicate::RegionPredicate {
282 lifetime: clean_lifetime(wrp.lifetime, cx),
283 bounds: wrp.bounds.iter().filter_map(|x| clean_generic_bound(x, cx)).collect(),
286 hir::WherePredicate::EqPredicate(ref wrp) => WherePredicate::EqPredicate {
287 lhs: Box::new(clean_ty(wrp.lhs_ty, cx)),
288 rhs: Box::new(clean_ty(wrp.rhs_ty, cx).into()),
289 bound_params: Vec::new(),
294 pub(crate) fn clean_predicate<'tcx>(
295 predicate: ty::Predicate<'tcx>,
296 cx: &mut DocContext<'tcx>,
297 ) -> Option<WherePredicate> {
298 let bound_predicate = predicate.kind();
299 match bound_predicate.skip_binder() {
300 ty::PredicateKind::Clause(ty::Clause::Trait(pred)) => {
301 clean_poly_trait_predicate(bound_predicate.rebind(pred), cx)
303 ty::PredicateKind::Clause(ty::Clause::RegionOutlives(pred)) => {
304 clean_region_outlives_predicate(pred)
306 ty::PredicateKind::Clause(ty::Clause::TypeOutlives(pred)) => {
307 clean_type_outlives_predicate(pred, cx)
309 ty::PredicateKind::Clause(ty::Clause::Projection(pred)) => {
310 Some(clean_projection_predicate(bound_predicate.rebind(pred), cx))
312 ty::PredicateKind::ConstEvaluatable(..) => None,
313 ty::PredicateKind::WellFormed(..) => None,
315 ty::PredicateKind::Subtype(..)
316 | ty::PredicateKind::Coerce(..)
317 | ty::PredicateKind::ObjectSafe(..)
318 | ty::PredicateKind::ClosureKind(..)
319 | ty::PredicateKind::ConstEquate(..)
320 | ty::PredicateKind::Ambiguous
321 | ty::PredicateKind::TypeWellFormedFromEnv(..) => panic!("not user writable"),
325 fn clean_poly_trait_predicate<'tcx>(
326 pred: ty::PolyTraitPredicate<'tcx>,
327 cx: &mut DocContext<'tcx>,
328 ) -> Option<WherePredicate> {
329 // `T: ~const Destruct` is hidden because `T: Destruct` is a no-op.
330 if pred.skip_binder().constness == ty::BoundConstness::ConstIfConst
331 && Some(pred.skip_binder().def_id()) == cx.tcx.lang_items().destruct_trait()
336 let poly_trait_ref = pred.map_bound(|pred| pred.trait_ref);
337 Some(WherePredicate::BoundPredicate {
338 ty: clean_middle_ty(poly_trait_ref.self_ty(), cx, None),
339 bounds: vec![clean_poly_trait_ref_with_bindings(cx, poly_trait_ref, ThinVec::new())],
340 bound_params: Vec::new(),
344 fn clean_region_outlives_predicate<'tcx>(
345 pred: ty::OutlivesPredicate<ty::Region<'tcx>, ty::Region<'tcx>>,
346 ) -> Option<WherePredicate> {
347 let ty::OutlivesPredicate(a, b) = pred;
349 Some(WherePredicate::RegionPredicate {
350 lifetime: clean_middle_region(a).expect("failed to clean lifetime"),
351 bounds: vec![GenericBound::Outlives(
352 clean_middle_region(b).expect("failed to clean bounds"),
357 fn clean_type_outlives_predicate<'tcx>(
358 pred: ty::OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>,
359 cx: &mut DocContext<'tcx>,
360 ) -> Option<WherePredicate> {
361 let ty::OutlivesPredicate(ty, lt) = pred;
363 Some(WherePredicate::BoundPredicate {
364 ty: clean_middle_ty(ty::Binder::dummy(ty), cx, None),
365 bounds: vec![GenericBound::Outlives(
366 clean_middle_region(lt).expect("failed to clean lifetimes"),
368 bound_params: Vec::new(),
372 fn clean_middle_term<'tcx>(
373 term: ty::Binder<'tcx, ty::Term<'tcx>>,
374 cx: &mut DocContext<'tcx>,
376 match term.skip_binder().unpack() {
377 ty::TermKind::Ty(ty) => Term::Type(clean_middle_ty(term.rebind(ty), cx, None)),
378 ty::TermKind::Const(c) => Term::Constant(clean_middle_const(term.rebind(c), cx)),
382 fn clean_hir_term<'tcx>(term: &hir::Term<'tcx>, cx: &mut DocContext<'tcx>) -> Term {
384 hir::Term::Ty(ty) => Term::Type(clean_ty(ty, cx)),
385 hir::Term::Const(c) => {
386 let def_id = cx.tcx.hir().local_def_id(c.hir_id);
387 Term::Constant(clean_middle_const(
388 ty::Binder::dummy(ty::Const::from_anon_const(cx.tcx, def_id)),
395 fn clean_projection_predicate<'tcx>(
396 pred: ty::Binder<'tcx, ty::ProjectionPredicate<'tcx>>,
397 cx: &mut DocContext<'tcx>,
398 ) -> WherePredicate {
399 let late_bound_regions = cx
401 .collect_referenced_late_bound_regions(&pred)
403 .filter_map(|br| match br {
404 ty::BrNamed(_, name) if br.is_named() => Some(Lifetime(name)),
409 WherePredicate::EqPredicate {
410 lhs: Box::new(clean_projection(pred.map_bound(|p| p.projection_ty), cx, None)),
411 rhs: Box::new(clean_middle_term(pred.map_bound(|p| p.term), cx)),
412 bound_params: late_bound_regions,
416 fn clean_projection<'tcx>(
417 ty: ty::Binder<'tcx, ty::ProjectionTy<'tcx>>,
418 cx: &mut DocContext<'tcx>,
419 def_id: Option<DefId>,
421 if cx.tcx.def_kind(ty.skip_binder().item_def_id) == DefKind::ImplTraitPlaceholder {
424 .explicit_item_bounds(ty.skip_binder().item_def_id)
426 .map(|(bound, _)| EarlyBinder(*bound).subst(cx.tcx, ty.skip_binder().substs))
427 .collect::<Vec<_>>();
428 return clean_middle_opaque_bounds(cx, bounds);
432 clean_trait_ref_with_bindings(cx, ty.map_bound(|ty| ty.trait_ref(cx.tcx)), ThinVec::new());
433 let self_type = clean_middle_ty(ty.map_bound(|ty| ty.self_ty()), cx, None);
434 let self_def_id = if let Some(def_id) = def_id {
435 cx.tcx.opt_parent(def_id).or(Some(def_id))
437 self_type.def_id(&cx.cache)
439 let should_show_cast = compute_should_show_cast(self_def_id, &trait_, &self_type);
440 Type::QPath(Box::new(QPathData {
441 assoc: projection_to_path_segment(ty, cx),
448 fn compute_should_show_cast(self_def_id: Option<DefId>, trait_: &Path, self_type: &Type) -> bool {
449 !trait_.segments.is_empty()
451 .zip(Some(trait_.def_id()))
452 .map_or(!self_type.is_self_type(), |(id, trait_)| id != trait_)
455 fn projection_to_path_segment<'tcx>(
456 ty: ty::Binder<'tcx, ty::ProjectionTy<'tcx>>,
457 cx: &mut DocContext<'tcx>,
459 let item = cx.tcx.associated_item(ty.skip_binder().item_def_id);
460 let generics = cx.tcx.generics_of(ty.skip_binder().item_def_id);
463 args: GenericArgs::AngleBracketed {
464 args: substs_to_args(cx, ty.map_bound(|ty| &ty.substs[generics.parent_count..]), false)
466 bindings: Default::default(),
471 fn clean_generic_param_def<'tcx>(
472 def: &ty::GenericParamDef,
473 cx: &mut DocContext<'tcx>,
474 ) -> GenericParamDef {
475 let (name, kind) = match def.kind {
476 ty::GenericParamDefKind::Lifetime => {
477 (def.name, GenericParamDefKind::Lifetime { outlives: vec![] })
479 ty::GenericParamDefKind::Type { has_default, synthetic, .. } => {
480 let default = if has_default {
481 Some(clean_middle_ty(
482 ty::Binder::dummy(cx.tcx.type_of(def.def_id)),
491 GenericParamDefKind::Type {
493 bounds: vec![], // These are filled in from the where-clauses.
494 default: default.map(Box::new),
499 ty::GenericParamDefKind::Const { has_default } => (
501 GenericParamDefKind::Const {
503 ty: Box::new(clean_middle_ty(
504 ty::Binder::dummy(cx.tcx.type_of(def.def_id)),
508 default: match has_default {
509 true => Some(Box::new(cx.tcx.const_param_default(def.def_id).to_string())),
516 GenericParamDef { name, kind }
519 fn clean_generic_param<'tcx>(
520 cx: &mut DocContext<'tcx>,
521 generics: Option<&hir::Generics<'tcx>>,
522 param: &hir::GenericParam<'tcx>,
523 ) -> GenericParamDef {
524 let did = cx.tcx.hir().local_def_id(param.hir_id);
525 let (name, kind) = match param.kind {
526 hir::GenericParamKind::Lifetime { .. } => {
527 let outlives = if let Some(generics) = generics {
529 .outlives_for_param(did)
530 .filter(|bp| !bp.in_where_clause)
531 .flat_map(|bp| bp.bounds)
532 .map(|bound| match bound {
533 hir::GenericBound::Outlives(lt) => clean_lifetime(lt, cx),
540 (param.name.ident().name, GenericParamDefKind::Lifetime { outlives })
542 hir::GenericParamKind::Type { ref default, synthetic } => {
543 let bounds = if let Some(generics) = generics {
545 .bounds_for_param(did)
546 .filter(|bp| bp.origin != PredicateOrigin::WhereClause)
547 .flat_map(|bp| bp.bounds)
548 .filter_map(|x| clean_generic_bound(x, cx))
554 param.name.ident().name,
555 GenericParamDefKind::Type {
556 did: did.to_def_id(),
558 default: default.map(|t| clean_ty(t, cx)).map(Box::new),
563 hir::GenericParamKind::Const { ty, default } => (
564 param.name.ident().name,
565 GenericParamDefKind::Const {
566 did: did.to_def_id(),
567 ty: Box::new(clean_ty(ty, cx)),
568 default: default.map(|ct| {
569 let def_id = cx.tcx.hir().local_def_id(ct.hir_id);
570 Box::new(ty::Const::from_anon_const(cx.tcx, def_id).to_string())
576 GenericParamDef { name, kind }
579 /// Synthetic type-parameters are inserted after normal ones.
580 /// In order for normal parameters to be able to refer to synthetic ones,
581 /// scans them first.
582 fn is_impl_trait(param: &hir::GenericParam<'_>) -> bool {
584 hir::GenericParamKind::Type { synthetic, .. } => synthetic,
589 /// This can happen for `async fn`, e.g. `async fn f<'_>(&'_ self)`.
591 /// See `lifetime_to_generic_param` in `rustc_ast_lowering` for more information.
592 fn is_elided_lifetime(param: &hir::GenericParam<'_>) -> bool {
593 matches!(param.kind, hir::GenericParamKind::Lifetime { kind: hir::LifetimeParamKind::Elided })
596 pub(crate) fn clean_generics<'tcx>(
597 gens: &hir::Generics<'tcx>,
598 cx: &mut DocContext<'tcx>,
600 let impl_trait_params = gens
603 .filter(|param| is_impl_trait(param))
605 let param = clean_generic_param(cx, Some(gens), param);
607 GenericParamDefKind::Lifetime { .. } => unreachable!(),
608 GenericParamDefKind::Type { did, ref bounds, .. } => {
609 cx.impl_trait_bounds.insert(did.into(), bounds.clone());
611 GenericParamDefKind::Const { .. } => unreachable!(),
615 .collect::<Vec<_>>();
617 let mut bound_predicates = FxIndexMap::default();
618 let mut region_predicates = FxIndexMap::default();
619 let mut eq_predicates = ThinVec::default();
620 for pred in gens.predicates.iter().filter_map(|x| clean_where_predicate(x, cx)) {
622 WherePredicate::BoundPredicate { ty, bounds, bound_params } => {
623 match bound_predicates.entry(ty) {
624 IndexEntry::Vacant(v) => {
625 v.insert((bounds, bound_params));
627 IndexEntry::Occupied(mut o) => {
628 // we merge both bounds.
629 for bound in bounds {
630 if !o.get().0.contains(&bound) {
631 o.get_mut().0.push(bound);
634 for bound_param in bound_params {
635 if !o.get().1.contains(&bound_param) {
636 o.get_mut().1.push(bound_param);
642 WherePredicate::RegionPredicate { lifetime, bounds } => {
643 match region_predicates.entry(lifetime) {
644 IndexEntry::Vacant(v) => {
647 IndexEntry::Occupied(mut o) => {
648 // we merge both bounds.
649 for bound in bounds {
650 if !o.get().contains(&bound) {
651 o.get_mut().push(bound);
657 WherePredicate::EqPredicate { lhs, rhs, bound_params } => {
658 eq_predicates.push(WherePredicate::EqPredicate { lhs, rhs, bound_params });
663 let mut params = ThinVec::with_capacity(gens.params.len());
664 // In this loop, we gather the generic parameters (`<'a, B: 'a>`) and check if they have
665 // bounds in the where predicates. If so, we move their bounds into the where predicates
666 // while also preventing duplicates.
667 for p in gens.params.iter().filter(|p| !is_impl_trait(p) && !is_elided_lifetime(p)) {
668 let mut p = clean_generic_param(cx, Some(gens), p);
670 GenericParamDefKind::Lifetime { ref mut outlives } => {
671 if let Some(region_pred) = region_predicates.get_mut(&Lifetime(p.name)) {
672 // We merge bounds in the `where` clause.
673 for outlive in outlives.drain(..) {
674 let outlive = GenericBound::Outlives(outlive);
675 if !region_pred.contains(&outlive) {
676 region_pred.push(outlive);
681 GenericParamDefKind::Type { bounds, synthetic: false, .. } => {
682 if let Some(bound_pred) = bound_predicates.get_mut(&Type::Generic(p.name)) {
683 // We merge bounds in the `where` clause.
684 for bound in bounds.drain(..) {
685 if !bound_pred.0.contains(&bound) {
686 bound_pred.0.push(bound);
691 GenericParamDefKind::Type { .. } | GenericParamDefKind::Const { .. } => {
692 // nothing to do here.
697 params.extend(impl_trait_params);
701 where_predicates: bound_predicates
703 .map(|(ty, (bounds, bound_params))| WherePredicate::BoundPredicate {
711 .map(|(lifetime, bounds)| WherePredicate::RegionPredicate { lifetime, bounds }),
713 .chain(eq_predicates.into_iter())
718 fn clean_ty_generics<'tcx>(
719 cx: &mut DocContext<'tcx>,
721 preds: ty::GenericPredicates<'tcx>,
723 // Don't populate `cx.impl_trait_bounds` before `clean`ning `where` clauses,
724 // since `Clean for ty::Predicate` would consume them.
725 let mut impl_trait = BTreeMap::<ImplTraitParam, Vec<GenericBound>>::default();
727 // Bounds in the type_params and lifetimes fields are repeated in the
728 // predicates field (see rustc_hir_analysis::collect::ty_generics), so remove
730 let stripped_params = gens
733 .filter_map(|param| match param.kind {
734 ty::GenericParamDefKind::Lifetime if param.is_anonymous_lifetime() => None,
735 ty::GenericParamDefKind::Lifetime => Some(clean_generic_param_def(param, cx)),
736 ty::GenericParamDefKind::Type { synthetic, .. } => {
737 if param.name == kw::SelfUpper {
738 assert_eq!(param.index, 0);
742 impl_trait.insert(param.index.into(), vec![]);
745 Some(clean_generic_param_def(param, cx))
747 ty::GenericParamDefKind::Const { .. } => Some(clean_generic_param_def(param, cx)),
749 .collect::<ThinVec<GenericParamDef>>();
751 // param index -> [(trait DefId, associated type name & generics, type, higher-ranked params)]
752 let mut impl_trait_proj = FxHashMap::<
754 Vec<(DefId, PathSegment, ty::Binder<'_, Ty<'_>>, Vec<GenericParamDef>)>,
757 let where_predicates = preds
761 let mut projection = None;
762 let param_idx = (|| {
763 let bound_p = p.kind();
764 match bound_p.skip_binder() {
765 ty::PredicateKind::Clause(ty::Clause::Trait(pred)) => {
766 if let ty::Param(param) = pred.self_ty().kind() {
767 return Some(param.index);
770 ty::PredicateKind::Clause(ty::Clause::TypeOutlives(ty::OutlivesPredicate(
774 if let ty::Param(param) = ty.kind() {
775 return Some(param.index);
778 ty::PredicateKind::Clause(ty::Clause::Projection(p)) => {
779 if let ty::Param(param) = p.projection_ty.self_ty().kind() {
780 projection = Some(bound_p.rebind(p));
781 return Some(param.index);
790 if let Some(param_idx) = param_idx {
791 if let Some(b) = impl_trait.get_mut(¶m_idx.into()) {
792 let p: WherePredicate = clean_predicate(*p, cx)?;
799 .filter(|b| !b.is_sized_bound(cx)),
802 let proj = projection.map(|p| {
804 clean_projection(p.map_bound(|p| p.projection_ty), cx, None),
805 p.map_bound(|p| p.term),
808 if let Some(((_, trait_did, name), rhs)) = proj
810 .and_then(|(lhs, rhs): &(Type, _)| Some((lhs.projection()?, rhs)))
812 // FIXME(...): Remove this unwrap()
813 impl_trait_proj.entry(param_idx).or_default().push((
816 rhs.map_bound(|rhs| rhs.ty().unwrap()),
820 .map(|param| GenericParamDef::lifetime(param.0))
831 .collect::<Vec<_>>();
833 for (param, mut bounds) in impl_trait {
834 // Move trait bounds to the front.
835 bounds.sort_by_key(|b| !matches!(b, GenericBound::TraitBound(..)));
837 let crate::core::ImplTraitParam::ParamIndex(idx) = param else { unreachable!() };
838 if let Some(proj) = impl_trait_proj.remove(&idx) {
839 for (trait_did, name, rhs, bound_params) in proj {
840 let rhs = clean_middle_ty(rhs, cx, None);
841 simplify::merge_bounds(
852 cx.impl_trait_bounds.insert(param, bounds);
855 // Now that `cx.impl_trait_bounds` is populated, we can process
856 // remaining predicates which could contain `impl Trait`.
857 let mut where_predicates =
858 where_predicates.into_iter().flat_map(|p| clean_predicate(*p, cx)).collect::<Vec<_>>();
860 // In the surface language, all type parameters except `Self` have an
861 // implicit `Sized` bound unless removed with `?Sized`.
862 // However, in the list of where-predicates below, `Sized` appears like a
863 // normal bound: It's either present (the type is sized) or
864 // absent (the type is unsized) but never *maybe* (i.e. `?Sized`).
866 // This is unsuitable for rendering.
867 // Thus, as a first step remove all `Sized` bounds that should be implicit.
869 // Note that associated types also have an implicit `Sized` bound but we
870 // don't actually know the set of associated types right here so that's
871 // handled when cleaning associated types.
872 let mut sized_params = FxHashSet::default();
873 where_predicates.retain(|pred| {
874 if let WherePredicate::BoundPredicate { ty: Generic(g), bounds, .. } = pred
875 && *g != kw::SelfUpper
876 && bounds.iter().any(|b| b.is_sized_bound(cx))
878 sized_params.insert(*g);
885 // As a final step, go through the type parameters again and insert a
886 // `?Sized` bound for each one we didn't find to be `Sized`.
887 for tp in &stripped_params {
888 if let types::GenericParamDefKind::Type { .. } = tp.kind
889 && !sized_params.contains(&tp.name)
891 where_predicates.push(WherePredicate::BoundPredicate {
892 ty: Type::Generic(tp.name),
893 bounds: vec![GenericBound::maybe_sized(cx)],
894 bound_params: Vec::new(),
899 // It would be nice to collect all of the bounds on a type and recombine
900 // them if possible, to avoid e.g., `where T: Foo, T: Bar, T: Sized, T: 'a`
901 // and instead see `where T: Foo + Bar + Sized + 'a`
904 params: stripped_params,
905 where_predicates: simplify::where_clauses(cx, where_predicates),
909 fn clean_fn_or_proc_macro<'tcx>(
910 item: &hir::Item<'tcx>,
911 sig: &hir::FnSig<'tcx>,
912 generics: &hir::Generics<'tcx>,
913 body_id: hir::BodyId,
915 cx: &mut DocContext<'tcx>,
917 let attrs = cx.tcx.hir().attrs(item.hir_id());
918 let macro_kind = attrs.iter().find_map(|a| {
919 if a.has_name(sym::proc_macro) {
920 Some(MacroKind::Bang)
921 } else if a.has_name(sym::proc_macro_derive) {
922 Some(MacroKind::Derive)
923 } else if a.has_name(sym::proc_macro_attribute) {
924 Some(MacroKind::Attr)
931 if kind == MacroKind::Derive {
933 .lists(sym::proc_macro_derive)
934 .find_map(|mi| mi.ident())
935 .expect("proc-macro derives require a name")
939 let mut helpers = Vec::new();
940 for mi in attrs.lists(sym::proc_macro_derive) {
941 if !mi.has_name(sym::attributes) {
945 if let Some(list) = mi.meta_item_list() {
946 for inner_mi in list {
947 if let Some(ident) = inner_mi.ident() {
948 helpers.push(ident.name);
953 ProcMacroItem(ProcMacro { kind, helpers })
956 let mut func = clean_function(cx, sig, generics, FunctionArgs::Body(body_id));
957 clean_fn_decl_legacy_const_generics(&mut func, attrs);
963 /// This is needed to make it more "readable" when documenting functions using
964 /// `rustc_legacy_const_generics`. More information in
965 /// <https://github.com/rust-lang/rust/issues/83167>.
966 fn clean_fn_decl_legacy_const_generics(func: &mut Function, attrs: &[ast::Attribute]) {
967 for meta_item_list in attrs
969 .filter(|a| a.has_name(sym::rustc_legacy_const_generics))
970 .filter_map(|a| a.meta_item_list())
972 for (pos, literal) in meta_item_list.iter().filter_map(|meta| meta.lit()).enumerate() {
974 ast::LitKind::Int(a, _) => {
975 let gen = func.generics.params.remove(0);
976 if let GenericParamDef { name, kind: GenericParamDefKind::Const { ty, .. } } =
982 .insert(a as _, Argument { name, type_: *ty, is_const: true });
984 panic!("unexpected non const in position {pos}");
987 _ => panic!("invalid arg index"),
993 enum FunctionArgs<'tcx> {
995 Names(&'tcx [Ident]),
998 fn clean_function<'tcx>(
999 cx: &mut DocContext<'tcx>,
1000 sig: &hir::FnSig<'tcx>,
1001 generics: &hir::Generics<'tcx>,
1002 args: FunctionArgs<'tcx>,
1003 ) -> Box<Function> {
1004 let (generics, decl) = enter_impl_trait(cx, |cx| {
1005 // NOTE: generics must be cleaned before args
1006 let generics = clean_generics(generics, cx);
1007 let args = match args {
1008 FunctionArgs::Body(body_id) => {
1009 clean_args_from_types_and_body_id(cx, sig.decl.inputs, body_id)
1011 FunctionArgs::Names(names) => {
1012 clean_args_from_types_and_names(cx, sig.decl.inputs, names)
1015 let mut decl = clean_fn_decl_with_args(cx, sig.decl, args);
1016 if sig.header.is_async() {
1017 decl.output = decl.sugared_async_return_type();
1021 Box::new(Function { decl, generics })
1024 fn clean_args_from_types_and_names<'tcx>(
1025 cx: &mut DocContext<'tcx>,
1026 types: &[hir::Ty<'tcx>],
1033 .map(|(i, ty)| Argument {
1034 type_: clean_ty(ty, cx),
1037 .map(|ident| ident.name)
1038 .filter(|ident| !ident.is_empty())
1039 .unwrap_or(kw::Underscore),
1046 fn clean_args_from_types_and_body_id<'tcx>(
1047 cx: &mut DocContext<'tcx>,
1048 types: &[hir::Ty<'tcx>],
1049 body_id: hir::BodyId,
1051 let body = cx.tcx.hir().body(body_id);
1057 .map(|(i, ty)| Argument {
1058 name: name_from_pat(body.params[i].pat),
1059 type_: clean_ty(ty, cx),
1066 fn clean_fn_decl_with_args<'tcx>(
1067 cx: &mut DocContext<'tcx>,
1068 decl: &hir::FnDecl<'tcx>,
1071 let output = match decl.output {
1072 hir::FnRetTy::Return(typ) => Return(clean_ty(typ, cx)),
1073 hir::FnRetTy::DefaultReturn(..) => DefaultReturn,
1075 FnDecl { inputs: args, output, c_variadic: decl.c_variadic }
1078 fn clean_fn_decl_from_did_and_sig<'tcx>(
1079 cx: &mut DocContext<'tcx>,
1081 sig: ty::PolyFnSig<'tcx>,
1083 let mut names = did.map_or(&[] as &[_], |did| cx.tcx.fn_arg_names(did)).iter();
1085 // We assume all empty tuples are default return type. This theoretically can discard `-> ()`,
1086 // but shouldn't change any code meaning.
1087 let output = match clean_middle_ty(sig.output(), cx, None) {
1088 Type::Tuple(inner) if inner.is_empty() => DefaultReturn,
1094 c_variadic: sig.skip_binder().c_variadic,
1100 type_: clean_middle_ty(t.map_bound(|t| *t), cx, None),
1104 .filter(|i| !i.is_empty())
1105 .unwrap_or(kw::Underscore),
1113 fn clean_trait_ref<'tcx>(trait_ref: &hir::TraitRef<'tcx>, cx: &mut DocContext<'tcx>) -> Path {
1114 let path = clean_path(trait_ref.path, cx);
1115 register_res(cx, path.res);
1119 fn clean_poly_trait_ref<'tcx>(
1120 poly_trait_ref: &hir::PolyTraitRef<'tcx>,
1121 cx: &mut DocContext<'tcx>,
1124 trait_: clean_trait_ref(&poly_trait_ref.trait_ref, cx),
1125 generic_params: poly_trait_ref
1126 .bound_generic_params
1128 .filter(|p| !is_elided_lifetime(p))
1129 .map(|x| clean_generic_param(cx, None, x))
1134 fn clean_trait_item<'tcx>(trait_item: &hir::TraitItem<'tcx>, cx: &mut DocContext<'tcx>) -> Item {
1135 let local_did = trait_item.owner_id.to_def_id();
1136 cx.with_param_env(local_did, |cx| {
1137 let inner = match trait_item.kind {
1138 hir::TraitItemKind::Const(ty, Some(default)) => AssocConstItem(
1140 ConstantKind::Local { def_id: local_did, body: default },
1142 hir::TraitItemKind::Const(ty, None) => TyAssocConstItem(clean_ty(ty, cx)),
1143 hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Provided(body)) => {
1144 let m = clean_function(cx, sig, trait_item.generics, FunctionArgs::Body(body));
1147 hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Required(names)) => {
1148 let m = clean_function(cx, sig, trait_item.generics, FunctionArgs::Names(names));
1151 hir::TraitItemKind::Type(bounds, Some(default)) => {
1152 let generics = enter_impl_trait(cx, |cx| clean_generics(trait_item.generics, cx));
1153 let bounds = bounds.iter().filter_map(|x| clean_generic_bound(x, cx)).collect();
1155 clean_middle_ty(ty::Binder::dummy(hir_ty_to_ty(cx.tcx, default)), cx, None);
1158 type_: clean_ty(default, cx),
1160 item_type: Some(item_type),
1165 hir::TraitItemKind::Type(bounds, None) => {
1166 let generics = enter_impl_trait(cx, |cx| clean_generics(trait_item.generics, cx));
1167 let bounds = bounds.iter().filter_map(|x| clean_generic_bound(x, cx)).collect();
1168 TyAssocTypeItem(generics, bounds)
1171 Item::from_def_id_and_parts(local_did, Some(trait_item.ident.name), inner, cx)
1175 pub(crate) fn clean_impl_item<'tcx>(
1176 impl_: &hir::ImplItem<'tcx>,
1177 cx: &mut DocContext<'tcx>,
1179 let local_did = impl_.owner_id.to_def_id();
1180 cx.with_param_env(local_did, |cx| {
1181 let inner = match impl_.kind {
1182 hir::ImplItemKind::Const(ty, expr) => {
1183 let default = ConstantKind::Local { def_id: local_did, body: expr };
1184 AssocConstItem(clean_ty(ty, cx), default)
1186 hir::ImplItemKind::Fn(ref sig, body) => {
1187 let m = clean_function(cx, sig, impl_.generics, FunctionArgs::Body(body));
1188 let defaultness = cx.tcx.impl_defaultness(impl_.owner_id);
1189 MethodItem(m, Some(defaultness))
1191 hir::ImplItemKind::Type(hir_ty) => {
1192 let type_ = clean_ty(hir_ty, cx);
1193 let generics = clean_generics(impl_.generics, cx);
1195 clean_middle_ty(ty::Binder::dummy(hir_ty_to_ty(cx.tcx, hir_ty)), cx, None);
1197 Box::new(Typedef { type_, generics, item_type: Some(item_type) }),
1203 Item::from_def_id_and_parts(local_did, Some(impl_.ident.name), inner, cx)
1207 pub(crate) fn clean_middle_assoc_item<'tcx>(
1208 assoc_item: &ty::AssocItem,
1209 cx: &mut DocContext<'tcx>,
1212 let kind = match assoc_item.kind {
1213 ty::AssocKind::Const => {
1214 let ty = clean_middle_ty(
1215 ty::Binder::dummy(tcx.type_of(assoc_item.def_id)),
1217 Some(assoc_item.def_id),
1220 let provided = match assoc_item.container {
1221 ty::ImplContainer => true,
1222 ty::TraitContainer => tcx.impl_defaultness(assoc_item.def_id).has_value(),
1225 AssocConstItem(ty, ConstantKind::Extern { def_id: assoc_item.def_id })
1227 TyAssocConstItem(ty)
1230 ty::AssocKind::Fn => {
1231 let sig = tcx.fn_sig(assoc_item.def_id);
1233 let late_bound_regions = sig.bound_vars().into_iter().filter_map(|var| match var {
1234 ty::BoundVariableKind::Region(ty::BrNamed(_, name))
1235 if name != kw::UnderscoreLifetime =>
1237 Some(GenericParamDef::lifetime(name))
1242 let mut generics = clean_ty_generics(
1244 tcx.generics_of(assoc_item.def_id),
1245 tcx.explicit_predicates_of(assoc_item.def_id),
1247 // FIXME: This does not place parameters in source order (late-bound ones come last)
1248 generics.params.extend(late_bound_regions);
1250 let mut decl = clean_fn_decl_from_did_and_sig(cx, Some(assoc_item.def_id), sig);
1252 if assoc_item.fn_has_self_parameter {
1253 let self_ty = match assoc_item.container {
1254 ty::ImplContainer => tcx.type_of(assoc_item.container_id(tcx)),
1255 ty::TraitContainer => tcx.types.self_param,
1257 let self_arg_ty = sig.input(0).skip_binder();
1258 if self_arg_ty == self_ty {
1259 decl.inputs.values[0].type_ = Generic(kw::SelfUpper);
1260 } else if let ty::Ref(_, ty, _) = *self_arg_ty.kind() {
1262 match decl.inputs.values[0].type_ {
1263 BorrowedRef { ref mut type_, .. } => **type_ = Generic(kw::SelfUpper),
1264 _ => unreachable!(),
1270 let provided = match assoc_item.container {
1271 ty::ImplContainer => true,
1272 ty::TraitContainer => assoc_item.defaultness(tcx).has_value(),
1275 let defaultness = match assoc_item.container {
1276 ty::ImplContainer => Some(assoc_item.defaultness(tcx)),
1277 ty::TraitContainer => None,
1279 MethodItem(Box::new(Function { generics, decl }), defaultness)
1281 TyMethodItem(Box::new(Function { generics, decl }))
1284 ty::AssocKind::Type => {
1285 let my_name = assoc_item.name;
1287 fn param_eq_arg(param: &GenericParamDef, arg: &GenericArg) -> bool {
1288 match (¶m.kind, arg) {
1289 (GenericParamDefKind::Type { .. }, GenericArg::Type(Type::Generic(ty)))
1290 if *ty == param.name =>
1294 (GenericParamDefKind::Lifetime { .. }, GenericArg::Lifetime(Lifetime(lt)))
1295 if *lt == param.name =>
1299 (GenericParamDefKind::Const { .. }, GenericArg::Const(c)) => match &c.kind {
1300 ConstantKind::TyConst { expr } => **expr == *param.name.as_str(),
1307 if let ty::TraitContainer = assoc_item.container {
1308 let bounds = tcx.explicit_item_bounds(assoc_item.def_id);
1309 let predicates = tcx.explicit_predicates_of(assoc_item.def_id).predicates;
1311 tcx.arena.alloc_from_iter(bounds.into_iter().chain(predicates).copied());
1312 let mut generics = clean_ty_generics(
1314 tcx.generics_of(assoc_item.def_id),
1315 ty::GenericPredicates { parent: None, predicates },
1317 // Filter out the bounds that are (likely?) directly attached to the associated type,
1318 // as opposed to being located in the where clause.
1319 let mut bounds: Vec<GenericBound> = Vec::new();
1320 generics.where_predicates.retain_mut(|pred| match *pred {
1321 WherePredicate::BoundPredicate {
1322 ty: QPath(box QPathData { ref assoc, ref self_type, ref trait_, .. }),
1323 bounds: ref mut pred_bounds,
1326 if assoc.name != my_name {
1329 if trait_.def_id() != assoc_item.container_id(tcx) {
1333 Generic(ref s) if *s == kw::SelfUpper => {}
1337 GenericArgs::AngleBracketed { args, bindings } => {
1338 if !bindings.is_empty()
1343 .any(|(param, arg)| !param_eq_arg(param, arg))
1348 GenericArgs::Parenthesized { .. } => {
1349 // The only time this happens is if we're inside the rustdoc for Fn(),
1350 // which only has one associated type, which is not a GAT, so whatever.
1353 bounds.extend(mem::replace(pred_bounds, Vec::new()));
1358 // Our Sized/?Sized bound didn't get handled when creating the generics
1359 // because we didn't actually get our whole set of bounds until just now
1360 // (some of them may have come from the trait). If we do have a sized
1361 // bound, we remove it, and if we don't then we add the `?Sized` bound
1363 match bounds.iter().position(|b| b.is_sized_bound(cx)) {
1367 None => bounds.push(GenericBound::maybe_sized(cx)),
1369 // Move bounds that are (likely) directly attached to the parameters of the
1370 // (generic) associated type from the where clause to the respective parameter.
1371 // There is no guarantee that this is what the user actually wrote but we have
1372 // no way of knowing.
1373 let mut where_predicates = ThinVec::new();
1374 for mut pred in generics.where_predicates {
1375 if let WherePredicate::BoundPredicate { ty: Generic(arg), bounds, .. } = &mut pred
1376 && let Some(GenericParamDef {
1377 kind: GenericParamDefKind::Type { bounds: param_bounds, .. },
1379 }) = generics.params.iter_mut().find(|param| ¶m.name == arg)
1381 param_bounds.append(bounds);
1382 } else if let WherePredicate::RegionPredicate { lifetime: Lifetime(arg), bounds } = &mut pred
1383 && let Some(GenericParamDef {
1384 kind: GenericParamDefKind::Lifetime { outlives: param_bounds },
1386 }) = generics.params.iter_mut().find(|param| ¶m.name == arg) {
1387 param_bounds.extend(bounds.drain(..).map(|bound| match bound {
1388 GenericBound::Outlives(lifetime) => lifetime,
1389 _ => unreachable!(),
1392 where_predicates.push(pred);
1395 generics.where_predicates = where_predicates;
1397 if tcx.impl_defaultness(assoc_item.def_id).has_value() {
1400 type_: clean_middle_ty(
1401 ty::Binder::dummy(tcx.type_of(assoc_item.def_id)),
1403 Some(assoc_item.def_id),
1406 // FIXME: should we obtain the Type from HIR and pass it on here?
1412 TyAssocTypeItem(generics, bounds)
1415 // FIXME: when could this happen? Associated items in inherent impls?
1418 type_: clean_middle_ty(
1419 ty::Binder::dummy(tcx.type_of(assoc_item.def_id)),
1421 Some(assoc_item.def_id),
1423 generics: Generics {
1424 params: ThinVec::new(),
1425 where_predicates: ThinVec::new(),
1435 Item::from_def_id_and_parts(assoc_item.def_id, Some(assoc_item.name), kind, cx)
1438 fn clean_qpath<'tcx>(hir_ty: &hir::Ty<'tcx>, cx: &mut DocContext<'tcx>) -> Type {
1439 let hir::Ty { hir_id: _, span, ref kind } = *hir_ty;
1440 let hir::TyKind::Path(qpath) = kind else { unreachable!() };
1443 hir::QPath::Resolved(None, path) => {
1444 if let Res::Def(DefKind::TyParam, did) = path.res {
1445 if let Some(new_ty) = cx.substs.get(&did).and_then(|p| p.as_ty()).cloned() {
1448 if let Some(bounds) = cx.impl_trait_bounds.remove(&did.into()) {
1449 return ImplTrait(bounds);
1453 if let Some(expanded) = maybe_expand_private_type_alias(cx, path) {
1456 let path = clean_path(path, cx);
1457 resolve_type(cx, path)
1460 hir::QPath::Resolved(Some(qself), p) => {
1461 // Try to normalize `<X as Y>::T` to a type
1462 let ty = hir_ty_to_ty(cx.tcx, hir_ty);
1463 // `hir_to_ty` can return projection types with escaping vars for GATs, e.g. `<() as Trait>::Gat<'_>`
1464 if !ty.has_escaping_bound_vars() {
1465 if let Some(normalized_value) = normalize(cx, ty::Binder::dummy(ty)) {
1466 return clean_middle_ty(normalized_value, cx, None);
1470 let trait_segments = &p.segments[..p.segments.len() - 1];
1471 let trait_def = cx.tcx.associated_item(p.res.def_id()).container_id(cx.tcx);
1472 let trait_ = self::Path {
1473 res: Res::Def(DefKind::Trait, trait_def),
1474 segments: trait_segments.iter().map(|x| clean_path_segment(x, cx)).collect(),
1476 register_res(cx, trait_.res);
1477 let self_def_id = DefId::local(qself.hir_id.owner.def_id.local_def_index);
1478 let self_type = clean_ty(qself, cx);
1479 let should_show_cast = compute_should_show_cast(Some(self_def_id), &trait_, &self_type);
1480 Type::QPath(Box::new(QPathData {
1481 assoc: clean_path_segment(p.segments.last().expect("segments were empty"), cx),
1487 hir::QPath::TypeRelative(qself, segment) => {
1488 let ty = hir_ty_to_ty(cx.tcx, hir_ty);
1489 let res = match ty.kind() {
1490 ty::Projection(proj) => Res::Def(DefKind::Trait, proj.trait_ref(cx.tcx).def_id),
1491 // Rustdoc handles `ty::Error`s by turning them into `Type::Infer`s.
1492 ty::Error(_) => return Type::Infer,
1493 // Otherwise, this is an inherent associated type.
1494 _ => return clean_middle_ty(ty::Binder::dummy(ty), cx, None),
1496 let trait_ = clean_path(&hir::Path { span, res, segments: &[] }, cx);
1497 register_res(cx, trait_.res);
1498 let self_def_id = res.opt_def_id();
1499 let self_type = clean_ty(qself, cx);
1500 let should_show_cast = compute_should_show_cast(self_def_id, &trait_, &self_type);
1501 Type::QPath(Box::new(QPathData {
1502 assoc: clean_path_segment(segment, cx),
1508 hir::QPath::LangItem(..) => bug!("clean: requiring documentation of lang item"),
1512 fn maybe_expand_private_type_alias<'tcx>(
1513 cx: &mut DocContext<'tcx>,
1514 path: &hir::Path<'tcx>,
1516 let Res::Def(DefKind::TyAlias, def_id) = path.res else { return None };
1517 // Substitute private type aliases
1518 let def_id = def_id.as_local()?;
1519 let alias = if !cx.cache.effective_visibilities.is_exported(cx.tcx, def_id.to_def_id()) {
1520 &cx.tcx.hir().expect_item(def_id).kind
1524 let hir::ItemKind::TyAlias(ty, generics) = alias else { return None };
1526 let provided_params = &path.segments.last().expect("segments were empty");
1527 let mut substs = FxHashMap::default();
1528 let generic_args = provided_params.args();
1530 let mut indices: hir::GenericParamCount = Default::default();
1531 for param in generics.params.iter() {
1533 hir::GenericParamKind::Lifetime { .. } => {
1535 let lifetime = generic_args.args.iter().find_map(|arg| match arg {
1536 hir::GenericArg::Lifetime(lt) => {
1537 if indices.lifetimes == j {
1545 if let Some(lt) = lifetime {
1546 let lt_def_id = cx.tcx.hir().local_def_id(param.hir_id);
1547 let cleaned = if !lt.is_anonymous() {
1548 clean_lifetime(lt, cx)
1552 substs.insert(lt_def_id.to_def_id(), SubstParam::Lifetime(cleaned));
1554 indices.lifetimes += 1;
1556 hir::GenericParamKind::Type { ref default, .. } => {
1557 let ty_param_def_id = cx.tcx.hir().local_def_id(param.hir_id);
1559 let type_ = generic_args.args.iter().find_map(|arg| match arg {
1560 hir::GenericArg::Type(ty) => {
1561 if indices.types == j {
1569 if let Some(ty) = type_ {
1570 substs.insert(ty_param_def_id.to_def_id(), SubstParam::Type(clean_ty(ty, cx)));
1571 } else if let Some(default) = *default {
1573 ty_param_def_id.to_def_id(),
1574 SubstParam::Type(clean_ty(default, cx)),
1579 hir::GenericParamKind::Const { .. } => {
1580 let const_param_def_id = cx.tcx.hir().local_def_id(param.hir_id);
1582 let const_ = generic_args.args.iter().find_map(|arg| match arg {
1583 hir::GenericArg::Const(ct) => {
1584 if indices.consts == j {
1592 if let Some(ct) = const_ {
1594 const_param_def_id.to_def_id(),
1595 SubstParam::Constant(clean_const(ct, cx)),
1598 // FIXME(const_generics_defaults)
1599 indices.consts += 1;
1604 Some(cx.enter_alias(substs, |cx| clean_ty(ty, cx)))
1607 pub(crate) fn clean_ty<'tcx>(ty: &hir::Ty<'tcx>, cx: &mut DocContext<'tcx>) -> Type {
1611 TyKind::Never => Primitive(PrimitiveType::Never),
1612 TyKind::Ptr(ref m) => RawPointer(m.mutbl, Box::new(clean_ty(m.ty, cx))),
1613 TyKind::Rptr(ref l, ref m) => {
1614 let lifetime = if l.is_anonymous() { None } else { Some(clean_lifetime(*l, cx)) };
1615 BorrowedRef { lifetime, mutability: m.mutbl, type_: Box::new(clean_ty(m.ty, cx)) }
1617 TyKind::Slice(ty) => Slice(Box::new(clean_ty(ty, cx))),
1618 TyKind::Array(ty, ref length) => {
1619 let length = match length {
1620 hir::ArrayLen::Infer(_, _) => "_".to_string(),
1621 hir::ArrayLen::Body(anon_const) => {
1622 let def_id = cx.tcx.hir().local_def_id(anon_const.hir_id);
1623 // NOTE(min_const_generics): We can't use `const_eval_poly` for constants
1624 // as we currently do not supply the parent generics to anonymous constants
1625 // but do allow `ConstKind::Param`.
1627 // `const_eval_poly` tries to first substitute generic parameters which
1628 // results in an ICE while manually constructing the constant and using `eval`
1629 // does nothing for `ConstKind::Param`.
1630 let ct = ty::Const::from_anon_const(cx.tcx, def_id);
1631 let param_env = cx.tcx.param_env(def_id);
1632 print_const(cx, ct.eval(cx.tcx, param_env))
1636 Array(Box::new(clean_ty(ty, cx)), length.into())
1638 TyKind::Tup(tys) => Tuple(tys.iter().map(|ty| clean_ty(ty, cx)).collect()),
1639 TyKind::OpaqueDef(item_id, _, _) => {
1640 let item = cx.tcx.hir().item(item_id);
1641 if let hir::ItemKind::OpaqueTy(ref ty) = item.kind {
1642 ImplTrait(ty.bounds.iter().filter_map(|x| clean_generic_bound(x, cx)).collect())
1647 TyKind::Path(_) => clean_qpath(ty, cx),
1648 TyKind::TraitObject(bounds, ref lifetime, _) => {
1649 let bounds = bounds.iter().map(|bound| clean_poly_trait_ref(bound, cx)).collect();
1651 if !lifetime.is_elided() { Some(clean_lifetime(*lifetime, cx)) } else { None };
1652 DynTrait(bounds, lifetime)
1654 TyKind::BareFn(barefn) => BareFunction(Box::new(clean_bare_fn_ty(barefn, cx))),
1655 // Rustdoc handles `TyKind::Err`s by turning them into `Type::Infer`s.
1656 TyKind::Infer | TyKind::Err | TyKind::Typeof(..) => Infer,
1660 /// Returns `None` if the type could not be normalized
1662 cx: &mut DocContext<'tcx>,
1663 ty: ty::Binder<'tcx, Ty<'tcx>>,
1664 ) -> Option<ty::Binder<'tcx, Ty<'tcx>>> {
1665 // HACK: low-churn fix for #79459 while we wait for a trait normalization fix
1666 if !cx.tcx.sess.opts.unstable_opts.normalize_docs {
1670 use crate::rustc_trait_selection::infer::TyCtxtInferExt;
1671 use crate::rustc_trait_selection::traits::query::normalize::QueryNormalizeExt;
1672 use rustc_middle::traits::ObligationCause;
1674 // Try to normalize `<X as Y>::T` to a type
1675 let infcx = cx.tcx.infer_ctxt().build();
1676 let normalized = infcx
1677 .at(&ObligationCause::dummy(), cx.param_env)
1678 .query_normalize(ty)
1679 .map(|resolved| infcx.resolve_vars_if_possible(resolved.value));
1681 Ok(normalized_value) => {
1682 debug!("normalized {:?} to {:?}", ty, normalized_value);
1683 Some(normalized_value)
1686 debug!("failed to normalize {:?}: {:?}", ty, err);
1692 #[instrument(level = "trace", skip(cx), ret)]
1693 pub(crate) fn clean_middle_ty<'tcx>(
1694 bound_ty: ty::Binder<'tcx, Ty<'tcx>>,
1695 cx: &mut DocContext<'tcx>,
1696 def_id: Option<DefId>,
1698 let bound_ty = normalize(cx, bound_ty).unwrap_or(bound_ty);
1699 match *bound_ty.skip_binder().kind() {
1700 ty::Never => Primitive(PrimitiveType::Never),
1701 ty::Bool => Primitive(PrimitiveType::Bool),
1702 ty::Char => Primitive(PrimitiveType::Char),
1703 ty::Int(int_ty) => Primitive(int_ty.into()),
1704 ty::Uint(uint_ty) => Primitive(uint_ty.into()),
1705 ty::Float(float_ty) => Primitive(float_ty.into()),
1706 ty::Str => Primitive(PrimitiveType::Str),
1707 ty::Slice(ty) => Slice(Box::new(clean_middle_ty(bound_ty.rebind(ty), cx, None))),
1708 ty::Array(ty, mut n) => {
1709 n = n.eval(cx.tcx, ty::ParamEnv::reveal_all());
1710 let n = print_const(cx, n);
1711 Array(Box::new(clean_middle_ty(bound_ty.rebind(ty), cx, None)), n.into())
1714 RawPointer(mt.mutbl, Box::new(clean_middle_ty(bound_ty.rebind(mt.ty), cx, None)))
1716 ty::Ref(r, ty, mutbl) => BorrowedRef {
1717 lifetime: clean_middle_region(r),
1719 type_: Box::new(clean_middle_ty(bound_ty.rebind(ty), cx, None)),
1721 ty::FnDef(..) | ty::FnPtr(_) => {
1722 // FIXME: should we merge the outer and inner binders somehow?
1723 let sig = bound_ty.skip_binder().fn_sig(cx.tcx);
1724 let decl = clean_fn_decl_from_did_and_sig(cx, None, sig);
1725 BareFunction(Box::new(BareFunctionDecl {
1726 unsafety: sig.unsafety(),
1727 generic_params: Vec::new(),
1732 ty::Adt(def, substs) => {
1733 let did = def.did();
1734 let kind = match def.adt_kind() {
1735 AdtKind::Struct => ItemType::Struct,
1736 AdtKind::Union => ItemType::Union,
1737 AdtKind::Enum => ItemType::Enum,
1739 inline::record_extern_fqn(cx, did, kind);
1740 let path = external_path(cx, did, false, ThinVec::new(), bound_ty.rebind(substs));
1743 ty::Foreign(did) => {
1744 inline::record_extern_fqn(cx, did, ItemType::ForeignType);
1745 let path = external_path(
1750 ty::Binder::dummy(InternalSubsts::empty()),
1754 ty::Dynamic(obj, ref reg, _) => {
1755 // HACK: pick the first `did` as the `did` of the trait object. Someone
1756 // might want to implement "native" support for marker-trait-only
1758 let mut dids = obj.auto_traits();
1761 .or_else(|| dids.next())
1762 .unwrap_or_else(|| panic!("found trait object `{bound_ty:?}` with no traits?"));
1763 let substs = match obj.principal() {
1764 Some(principal) => principal.map_bound(|p| p.substs),
1765 // marker traits have no substs.
1766 _ => ty::Binder::dummy(InternalSubsts::empty()),
1769 inline::record_extern_fqn(cx, did, ItemType::Trait);
1771 // FIXME(fmease): Hide the trait-object lifetime bound if it coincides with its default
1772 // to partially address #44306. Follow the rules outlined at
1773 // https://doc.rust-lang.org/reference/lifetime-elision.html#default-trait-object-lifetimes
1774 let lifetime = clean_middle_region(*reg);
1775 let mut bounds = dids
1777 let empty = ty::Binder::dummy(InternalSubsts::empty());
1778 let path = external_path(cx, did, false, ThinVec::new(), empty);
1779 inline::record_extern_fqn(cx, did, ItemType::Trait);
1780 PolyTrait { trait_: path, generic_params: Vec::new() }
1782 .collect::<Vec<_>>();
1785 .projection_bounds()
1786 .map(|pb| TypeBinding {
1787 assoc: projection_to_path_segment(
1790 // HACK(compiler-errors): Doesn't actually matter what self
1791 // type we put here, because we're only using the GAT's substs.
1792 .with_self_ty(cx.tcx, cx.tcx.types.self_param)
1797 kind: TypeBindingKind::Equality {
1798 term: clean_middle_term(pb.map_bound(|pb| pb.term), cx),
1803 let late_bound_regions: FxIndexSet<_> = obj
1805 .flat_map(|pb| pb.bound_vars())
1806 .filter_map(|br| match br {
1807 ty::BoundVariableKind::Region(ty::BrNamed(_, name))
1808 if name != kw::UnderscoreLifetime =>
1810 Some(GenericParamDef::lifetime(name))
1815 let late_bound_regions = late_bound_regions.into_iter().collect();
1817 let path = external_path(cx, did, false, bindings, substs);
1818 bounds.insert(0, PolyTrait { trait_: path, generic_params: late_bound_regions });
1820 DynTrait(bounds, lifetime)
1823 Tuple(t.iter().map(|t| clean_middle_ty(bound_ty.rebind(t), cx, None)).collect())
1826 ty::Projection(ref data) => clean_projection(bound_ty.rebind(*data), cx, def_id),
1828 ty::Param(ref p) => {
1829 if let Some(bounds) = cx.impl_trait_bounds.remove(&p.index.into()) {
1836 ty::Opaque(def_id, substs) => {
1837 // Grab the "TraitA + TraitB" from `impl TraitA + TraitB`,
1838 // by looking up the bounds associated with the def_id.
1841 .explicit_item_bounds(def_id)
1843 .map(|(bound, _)| EarlyBinder(*bound).subst(cx.tcx, substs))
1844 .collect::<Vec<_>>();
1845 clean_middle_opaque_bounds(cx, bounds)
1848 ty::Closure(..) => panic!("Closure"),
1849 ty::Generator(..) => panic!("Generator"),
1850 ty::Bound(..) => panic!("Bound"),
1851 ty::Placeholder(..) => panic!("Placeholder"),
1852 ty::GeneratorWitness(..) => panic!("GeneratorWitness"),
1853 ty::Infer(..) => panic!("Infer"),
1854 ty::Error(_) => panic!("Error"),
1858 fn clean_middle_opaque_bounds<'tcx>(
1859 cx: &mut DocContext<'tcx>,
1860 bounds: Vec<ty::Predicate<'tcx>>,
1862 let mut regions = vec![];
1863 let mut has_sized = false;
1864 let mut bounds = bounds
1866 .filter_map(|bound| {
1867 let bound_predicate = bound.kind();
1868 let trait_ref = match bound_predicate.skip_binder() {
1869 ty::PredicateKind::Clause(ty::Clause::Trait(tr)) => {
1870 bound_predicate.rebind(tr.trait_ref)
1872 ty::PredicateKind::Clause(ty::Clause::TypeOutlives(ty::OutlivesPredicate(
1876 if let Some(r) = clean_middle_region(reg) {
1877 regions.push(GenericBound::Outlives(r));
1884 if let Some(sized) = cx.tcx.lang_items().sized_trait() {
1885 if trait_ref.def_id() == sized {
1891 let bindings: ThinVec<_> = bounds
1893 .filter_map(|bound| {
1894 if let ty::PredicateKind::Clause(ty::Clause::Projection(proj)) =
1895 bound.kind().skip_binder()
1897 if proj.projection_ty.trait_ref(cx.tcx) == trait_ref.skip_binder() {
1899 assoc: projection_to_path_segment(
1900 bound.kind().rebind(proj.projection_ty),
1903 kind: TypeBindingKind::Equality {
1904 term: clean_middle_term(bound.kind().rebind(proj.term), cx),
1916 Some(clean_poly_trait_ref_with_bindings(cx, trait_ref, bindings))
1918 .collect::<Vec<_>>();
1919 bounds.extend(regions);
1920 if !has_sized && !bounds.is_empty() {
1921 bounds.insert(0, GenericBound::maybe_sized(cx));
1926 pub(crate) fn clean_field<'tcx>(field: &hir::FieldDef<'tcx>, cx: &mut DocContext<'tcx>) -> Item {
1927 let def_id = cx.tcx.hir().local_def_id(field.hir_id).to_def_id();
1928 clean_field_with_def_id(def_id, field.ident.name, clean_ty(field.ty, cx), cx)
1931 pub(crate) fn clean_middle_field<'tcx>(field: &ty::FieldDef, cx: &mut DocContext<'tcx>) -> Item {
1932 clean_field_with_def_id(
1935 clean_middle_ty(ty::Binder::dummy(cx.tcx.type_of(field.did)), cx, Some(field.did)),
1940 pub(crate) fn clean_field_with_def_id(
1944 cx: &mut DocContext<'_>,
1946 Item::from_def_id_and_parts(def_id, Some(name), StructFieldItem(ty), cx)
1949 pub(crate) fn clean_variant_def<'tcx>(variant: &ty::VariantDef, cx: &mut DocContext<'tcx>) -> Item {
1950 let kind = match variant.ctor_kind() {
1951 Some(CtorKind::Const) => Variant::CLike(match variant.discr {
1952 ty::VariantDiscr::Explicit(def_id) => Some(Discriminant { expr: None, value: def_id }),
1953 ty::VariantDiscr::Relative(_) => None,
1955 Some(CtorKind::Fn) => Variant::Tuple(
1956 variant.fields.iter().map(|field| clean_middle_field(field, cx)).collect(),
1958 None => Variant::Struct(VariantStruct {
1960 fields: variant.fields.iter().map(|field| clean_middle_field(field, cx)).collect(),
1963 Item::from_def_id_and_parts(variant.def_id, Some(variant.name), VariantItem(kind), cx)
1966 fn clean_variant_data<'tcx>(
1967 variant: &hir::VariantData<'tcx>,
1968 disr_expr: &Option<hir::AnonConst>,
1969 cx: &mut DocContext<'tcx>,
1972 hir::VariantData::Struct(..) => Variant::Struct(VariantStruct {
1974 fields: variant.fields().iter().map(|x| clean_field(x, cx)).collect(),
1976 hir::VariantData::Tuple(..) => {
1977 Variant::Tuple(variant.fields().iter().map(|x| clean_field(x, cx)).collect())
1979 hir::VariantData::Unit(..) => Variant::CLike(disr_expr.map(|disr| Discriminant {
1980 expr: Some(disr.body),
1981 value: cx.tcx.hir().local_def_id(disr.hir_id).to_def_id(),
1986 fn clean_path<'tcx>(path: &hir::Path<'tcx>, cx: &mut DocContext<'tcx>) -> Path {
1989 segments: path.segments.iter().map(|x| clean_path_segment(x, cx)).collect(),
1993 fn clean_generic_args<'tcx>(
1994 generic_args: &hir::GenericArgs<'tcx>,
1995 cx: &mut DocContext<'tcx>,
1997 if generic_args.parenthesized {
1998 let output = clean_ty(generic_args.bindings[0].ty(), cx);
1999 let output = if output != Type::Tuple(Vec::new()) { Some(Box::new(output)) } else { None };
2001 generic_args.inputs().iter().map(|x| clean_ty(x, cx)).collect::<Vec<_>>().into();
2002 GenericArgs::Parenthesized { inputs, output }
2004 let args = generic_args
2007 .map(|arg| match arg {
2008 hir::GenericArg::Lifetime(lt) if !lt.is_anonymous() => {
2009 GenericArg::Lifetime(clean_lifetime(*lt, cx))
2011 hir::GenericArg::Lifetime(_) => GenericArg::Lifetime(Lifetime::elided()),
2012 hir::GenericArg::Type(ty) => GenericArg::Type(clean_ty(ty, cx)),
2013 hir::GenericArg::Const(ct) => GenericArg::Const(Box::new(clean_const(ct, cx))),
2014 hir::GenericArg::Infer(_inf) => GenericArg::Infer,
2016 .collect::<Vec<_>>()
2019 generic_args.bindings.iter().map(|x| clean_type_binding(x, cx)).collect::<ThinVec<_>>();
2020 GenericArgs::AngleBracketed { args, bindings }
2024 fn clean_path_segment<'tcx>(
2025 path: &hir::PathSegment<'tcx>,
2026 cx: &mut DocContext<'tcx>,
2028 PathSegment { name: path.ident.name, args: clean_generic_args(path.args(), cx) }
2031 fn clean_bare_fn_ty<'tcx>(
2032 bare_fn: &hir::BareFnTy<'tcx>,
2033 cx: &mut DocContext<'tcx>,
2034 ) -> BareFunctionDecl {
2035 let (generic_params, decl) = enter_impl_trait(cx, |cx| {
2036 // NOTE: generics must be cleaned before args
2037 let generic_params = bare_fn
2040 .filter(|p| !is_elided_lifetime(p))
2041 .map(|x| clean_generic_param(cx, None, x))
2043 let args = clean_args_from_types_and_names(cx, bare_fn.decl.inputs, bare_fn.param_names);
2044 let decl = clean_fn_decl_with_args(cx, bare_fn.decl, args);
2045 (generic_params, decl)
2047 BareFunctionDecl { unsafety: bare_fn.unsafety, abi: bare_fn.abi, decl, generic_params }
2050 /// This visitor is used to go through only the "top level" of a item and not enter any sub
2051 /// item while looking for a given `Ident` which is stored into `item` if found.
2052 struct OneLevelVisitor<'hir> {
2053 map: rustc_middle::hir::map::Map<'hir>,
2054 item: Option<&'hir hir::Item<'hir>>,
2056 target_hir_id: hir::HirId,
2059 impl<'hir> OneLevelVisitor<'hir> {
2060 fn new(map: rustc_middle::hir::map::Map<'hir>, target_hir_id: hir::HirId) -> Self {
2061 Self { map, item: None, looking_for: Ident::empty(), target_hir_id }
2064 fn reset(&mut self, looking_for: Ident) {
2065 self.looking_for = looking_for;
2070 impl<'hir> hir::intravisit::Visitor<'hir> for OneLevelVisitor<'hir> {
2071 type NestedFilter = rustc_middle::hir::nested_filter::All;
2073 fn nested_visit_map(&mut self) -> Self::Map {
2077 fn visit_item(&mut self, item: &'hir hir::Item<'hir>) {
2078 if self.item.is_none()
2079 && item.ident == self.looking_for
2080 && matches!(item.kind, hir::ItemKind::Use(_, _))
2081 || item.hir_id() == self.target_hir_id
2083 self.item = Some(item);
2088 /// Because a `Use` item directly links to the imported item, we need to manually go through each
2089 /// import one by one. To do so, we go to the parent item and look for the `Ident` into it. Then,
2090 /// if we found the "end item" (the imported one), we stop there because we don't need its
2091 /// documentation. Otherwise, we repeat the same operation until we find the "end item".
2092 fn get_all_import_attributes<'hir>(
2093 mut item: &hir::Item<'hir>,
2095 target_hir_id: hir::HirId,
2096 attributes: &mut Vec<ast::Attribute>,
2098 let hir_map = tcx.hir();
2099 let mut visitor = OneLevelVisitor::new(hir_map, target_hir_id);
2100 // If the item is an import and has at least a path with two parts, we go into it.
2101 while let hir::ItemKind::Use(path, _) = item.kind &&
2102 path.segments.len() > 1 &&
2103 let hir::def::Res::Def(_, def_id) = path.segments[path.segments.len() - 2].res
2105 if let Some(hir::Node::Item(parent_item)) = hir_map.get_if_local(def_id) {
2106 // We add the attributes from this import into the list.
2107 attributes.extend_from_slice(hir_map.attrs(item.hir_id()));
2108 // We get the `Ident` we will be looking for into `item`.
2109 let looking_for = path.segments[path.segments.len() - 1].ident;
2110 visitor.reset(looking_for);
2111 hir::intravisit::walk_item(&mut visitor, parent_item);
2112 if let Some(i) = visitor.item {
2123 fn clean_maybe_renamed_item<'tcx>(
2124 cx: &mut DocContext<'tcx>,
2125 item: &hir::Item<'tcx>,
2126 renamed: Option<Symbol>,
2127 import_id: Option<hir::HirId>,
2131 let def_id = item.owner_id.to_def_id();
2132 let mut name = renamed.unwrap_or_else(|| cx.tcx.hir().name(item.hir_id()));
2133 cx.with_param_env(def_id, |cx| {
2134 let kind = match item.kind {
2135 ItemKind::Static(ty, mutability, body_id) => {
2136 StaticItem(Static { type_: clean_ty(ty, cx), mutability, expr: Some(body_id) })
2138 ItemKind::Const(ty, body_id) => ConstantItem(Constant {
2139 type_: clean_ty(ty, cx),
2140 kind: ConstantKind::Local { body: body_id, def_id },
2142 ItemKind::OpaqueTy(ref ty) => OpaqueTyItem(OpaqueTy {
2143 bounds: ty.bounds.iter().filter_map(|x| clean_generic_bound(x, cx)).collect(),
2144 generics: clean_generics(ty.generics, cx),
2146 ItemKind::TyAlias(hir_ty, generics) => {
2147 let rustdoc_ty = clean_ty(hir_ty, cx);
2148 let ty = clean_middle_ty(ty::Binder::dummy(hir_ty_to_ty(cx.tcx, hir_ty)), cx, None);
2149 TypedefItem(Box::new(Typedef {
2151 generics: clean_generics(generics, cx),
2152 item_type: Some(ty),
2155 ItemKind::Enum(ref def, generics) => EnumItem(Enum {
2156 variants: def.variants.iter().map(|v| clean_variant(v, cx)).collect(),
2157 generics: clean_generics(generics, cx),
2159 ItemKind::TraitAlias(generics, bounds) => TraitAliasItem(TraitAlias {
2160 generics: clean_generics(generics, cx),
2161 bounds: bounds.iter().filter_map(|x| clean_generic_bound(x, cx)).collect(),
2163 ItemKind::Union(ref variant_data, generics) => UnionItem(Union {
2164 generics: clean_generics(generics, cx),
2165 fields: variant_data.fields().iter().map(|x| clean_field(x, cx)).collect(),
2167 ItemKind::Struct(ref variant_data, generics) => StructItem(Struct {
2168 ctor_kind: variant_data.ctor_kind(),
2169 generics: clean_generics(generics, cx),
2170 fields: variant_data.fields().iter().map(|x| clean_field(x, cx)).collect(),
2172 ItemKind::Impl(impl_) => return clean_impl(impl_, item.hir_id(), cx),
2173 // proc macros can have a name set by attributes
2174 ItemKind::Fn(ref sig, generics, body_id) => {
2175 clean_fn_or_proc_macro(item, sig, generics, body_id, &mut name, cx)
2177 ItemKind::Macro(ref macro_def, _) => {
2178 let ty_vis = cx.tcx.visibility(def_id);
2180 source: display_macro_source(cx, name, macro_def, def_id, ty_vis),
2183 ItemKind::Trait(_, _, generics, bounds, item_ids) => {
2184 let items = item_ids
2186 .map(|ti| clean_trait_item(cx.tcx.hir().trait_item(ti.id), cx))
2189 TraitItem(Box::new(Trait {
2192 generics: clean_generics(generics, cx),
2193 bounds: bounds.iter().filter_map(|x| clean_generic_bound(x, cx)).collect(),
2196 ItemKind::ExternCrate(orig_name) => {
2197 return clean_extern_crate(item, name, orig_name, cx);
2199 ItemKind::Use(path, kind) => {
2200 return clean_use_statement(item, name, path, kind, cx, &mut FxHashSet::default());
2202 _ => unreachable!("not yet converted"),
2205 let mut extra_attrs = Vec::new();
2206 if let Some(hir::Node::Item(use_node)) =
2207 import_id.and_then(|hir_id| cx.tcx.hir().find(hir_id))
2209 // We get all the various imports' attributes.
2210 get_all_import_attributes(use_node, cx.tcx, item.hir_id(), &mut extra_attrs);
2213 if !extra_attrs.is_empty() {
2214 extra_attrs.extend_from_slice(inline::load_attrs(cx, def_id));
2215 let attrs = Attributes::from_ast(&extra_attrs);
2216 let cfg = extra_attrs.cfg(cx.tcx, &cx.cache.hidden_cfg);
2218 vec![Item::from_def_id_and_attrs_and_parts(
2226 vec![Item::from_def_id_and_parts(def_id, Some(name), kind, cx)]
2231 fn clean_variant<'tcx>(variant: &hir::Variant<'tcx>, cx: &mut DocContext<'tcx>) -> Item {
2232 let kind = VariantItem(clean_variant_data(&variant.data, &variant.disr_expr, cx));
2233 Item::from_hir_id_and_parts(variant.hir_id, Some(variant.ident.name), kind, cx)
2236 fn clean_impl<'tcx>(
2237 impl_: &hir::Impl<'tcx>,
2239 cx: &mut DocContext<'tcx>,
2242 let mut ret = Vec::new();
2243 let trait_ = impl_.of_trait.as_ref().map(|t| clean_trait_ref(t, cx));
2247 .map(|ii| clean_impl_item(tcx.hir().impl_item(ii.id), cx))
2248 .collect::<Vec<_>>();
2249 let def_id = tcx.hir().local_def_id(hir_id);
2251 // If this impl block is an implementation of the Deref trait, then we
2252 // need to try inlining the target's inherent impl blocks as well.
2253 if trait_.as_ref().map(|t| t.def_id()) == tcx.lang_items().deref_trait() {
2254 build_deref_target_impls(cx, &items, &mut ret);
2257 let for_ = clean_ty(impl_.self_ty, cx);
2258 let type_alias = for_.def_id(&cx.cache).and_then(|did| match tcx.def_kind(did) {
2259 DefKind::TyAlias => {
2260 Some(clean_middle_ty(ty::Binder::dummy(tcx.type_of(did)), cx, Some(did)))
2264 let mut make_item = |trait_: Option<Path>, for_: Type, items: Vec<Item>| {
2265 let kind = ImplItem(Box::new(Impl {
2266 unsafety: impl_.unsafety,
2267 generics: clean_generics(impl_.generics, cx),
2271 polarity: tcx.impl_polarity(def_id),
2272 kind: if utils::has_doc_flag(tcx, def_id.to_def_id(), sym::fake_variadic) {
2273 ImplKind::FakeVaradic
2278 Item::from_hir_id_and_parts(hir_id, None, kind, cx)
2280 if let Some(type_alias) = type_alias {
2281 ret.push(make_item(trait_.clone(), type_alias, items.clone()));
2283 ret.push(make_item(trait_, for_, items));
2287 fn clean_extern_crate<'tcx>(
2288 krate: &hir::Item<'tcx>,
2290 orig_name: Option<Symbol>,
2291 cx: &mut DocContext<'tcx>,
2293 // this is the ID of the `extern crate` statement
2294 let cnum = cx.tcx.extern_mod_stmt_cnum(krate.owner_id.def_id).unwrap_or(LOCAL_CRATE);
2295 // this is the ID of the crate itself
2296 let crate_def_id = cnum.as_def_id();
2297 let attrs = cx.tcx.hir().attrs(krate.hir_id());
2298 let ty_vis = cx.tcx.visibility(krate.owner_id);
2299 let please_inline = ty_vis.is_public()
2300 && attrs.iter().any(|a| {
2301 a.has_name(sym::doc)
2302 && match a.meta_item_list() {
2303 Some(l) => attr::list_contains_name(&l, sym::inline),
2308 let krate_owner_def_id = krate.owner_id.to_def_id();
2310 let mut visited = FxHashSet::default();
2312 let res = Res::Def(DefKind::Mod, crate_def_id);
2314 if let Some(items) = inline::try_inline(
2316 cx.tcx.parent_module(krate.hir_id()).to_def_id(),
2317 Some(krate_owner_def_id),
2327 // FIXME: using `from_def_id_and_kind` breaks `rustdoc/masked` for some reason
2330 attrs: Box::new(Attributes::from_ast(attrs)),
2331 item_id: crate_def_id.into(),
2332 kind: Box::new(ExternCrateItem { src: orig_name }),
2333 cfg: attrs.cfg(cx.tcx, &cx.cache.hidden_cfg),
2334 inline_stmt_id: Some(krate_owner_def_id),
2338 fn clean_use_statement<'tcx>(
2339 import: &hir::Item<'tcx>,
2341 path: &hir::UsePath<'tcx>,
2343 cx: &mut DocContext<'tcx>,
2344 inlined_names: &mut FxHashSet<(ItemType, Symbol)>,
2346 let mut items = Vec::new();
2347 let hir::UsePath { segments, ref res, span } = *path;
2349 if let Res::Def(DefKind::Ctor(..), _) | Res::SelfCtor(..) = res {
2352 let path = hir::Path { segments, res, span };
2353 items.append(&mut clean_use_statement_inner(import, name, &path, kind, cx, inlined_names));
2358 fn clean_use_statement_inner<'tcx>(
2359 import: &hir::Item<'tcx>,
2361 path: &hir::Path<'tcx>,
2363 cx: &mut DocContext<'tcx>,
2364 inlined_names: &mut FxHashSet<(ItemType, Symbol)>,
2366 // We need this comparison because some imports (for std types for example)
2367 // are "inserted" as well but directly by the compiler and they should not be
2368 // taken into account.
2369 if import.span.ctxt().outer_expn_data().kind == ExpnKind::AstPass(AstPass::StdImports) {
2373 let visibility = cx.tcx.visibility(import.owner_id);
2374 let attrs = cx.tcx.hir().attrs(import.hir_id());
2375 let inline_attr = attrs.lists(sym::doc).get_word_attr(sym::inline);
2376 let pub_underscore = visibility.is_public() && name == kw::Underscore;
2377 let current_mod = cx.tcx.parent_module_from_def_id(import.owner_id.def_id);
2379 // The parent of the module in which this import resides. This
2380 // is the same as `current_mod` if that's already the top
2382 let parent_mod = cx.tcx.parent_module_from_def_id(current_mod);
2384 // This checks if the import can be seen from a higher level module.
2385 // In other words, it checks if the visibility is the equivalent of
2386 // `pub(super)` or higher. If the current module is the top level
2387 // module, there isn't really a parent module, which makes the results
2388 // meaningless. In this case, we make sure the answer is `false`.
2389 let is_visible_from_parent_mod =
2390 visibility.is_accessible_from(parent_mod, cx.tcx) && !current_mod.is_top_level_module();
2393 if let Some(ref inline) = inline_attr {
2394 rustc_errors::struct_span_err!(
2398 "anonymous imports cannot be inlined"
2400 .span_label(import.span, "anonymous import")
2405 // We consider inlining the documentation of `pub use` statements, but we
2406 // forcefully don't inline if this is not public or if the
2407 // #[doc(no_inline)] attribute is present.
2408 // Don't inline doc(hidden) imports so they can be stripped at a later stage.
2409 let mut denied = cx.output_format.is_json()
2410 || !(visibility.is_public()
2411 || (cx.render_options.document_private && is_visible_from_parent_mod))
2413 || attrs.iter().any(|a| {
2414 a.has_name(sym::doc)
2415 && match a.meta_item_list() {
2417 attr::list_contains_name(&l, sym::no_inline)
2418 || attr::list_contains_name(&l, sym::hidden)
2424 // Also check whether imports were asked to be inlined, in case we're trying to re-export a
2425 // crate in Rust 2018+
2426 let path = clean_path(path, cx);
2427 let inner = if kind == hir::UseKind::Glob {
2429 let mut visited = FxHashSet::default();
2430 if let Some(items) = inline::try_inline_glob(cx, path.res, &mut visited, inlined_names)
2435 Import::new_glob(resolve_use_source(cx, path), true)
2437 if inline_attr.is_none() {
2438 if let Res::Def(DefKind::Mod, did) = path.res {
2439 if !did.is_local() && did.is_crate_root() {
2440 // if we're `pub use`ing an extern crate root, don't inline it unless we
2441 // were specifically asked for it
2447 let mut visited = FxHashSet::default();
2448 let import_def_id = import.owner_id.to_def_id();
2450 if let Some(mut items) = inline::try_inline(
2452 cx.tcx.parent_module(import.hir_id()).to_def_id(),
2453 Some(import_def_id),
2459 items.push(Item::from_def_id_and_parts(
2462 ImportItem(Import::new_simple(name, resolve_use_source(cx, path), false)),
2468 Import::new_simple(name, resolve_use_source(cx, path), true)
2471 vec![Item::from_def_id_and_parts(import.owner_id.to_def_id(), None, ImportItem(inner), cx)]
2474 fn clean_maybe_renamed_foreign_item<'tcx>(
2475 cx: &mut DocContext<'tcx>,
2476 item: &hir::ForeignItem<'tcx>,
2477 renamed: Option<Symbol>,
2479 let def_id = item.owner_id.to_def_id();
2480 cx.with_param_env(def_id, |cx| {
2481 let kind = match item.kind {
2482 hir::ForeignItemKind::Fn(decl, names, generics) => {
2483 let (generics, decl) = enter_impl_trait(cx, |cx| {
2484 // NOTE: generics must be cleaned before args
2485 let generics = clean_generics(generics, cx);
2486 let args = clean_args_from_types_and_names(cx, decl.inputs, names);
2487 let decl = clean_fn_decl_with_args(cx, decl, args);
2490 ForeignFunctionItem(Box::new(Function { decl, generics }))
2492 hir::ForeignItemKind::Static(ty, mutability) => {
2493 ForeignStaticItem(Static { type_: clean_ty(ty, cx), mutability, expr: None })
2495 hir::ForeignItemKind::Type => ForeignTypeItem,
2498 Item::from_hir_id_and_parts(
2500 Some(renamed.unwrap_or(item.ident.name)),
2507 fn clean_type_binding<'tcx>(
2508 type_binding: &hir::TypeBinding<'tcx>,
2509 cx: &mut DocContext<'tcx>,
2512 assoc: PathSegment {
2513 name: type_binding.ident.name,
2514 args: clean_generic_args(type_binding.gen_args, cx),
2516 kind: match type_binding.kind {
2517 hir::TypeBindingKind::Equality { ref term } => {
2518 TypeBindingKind::Equality { term: clean_hir_term(term, cx) }
2520 hir::TypeBindingKind::Constraint { bounds } => TypeBindingKind::Constraint {
2521 bounds: bounds.iter().filter_map(|b| clean_generic_bound(b, cx)).collect(),