1 //! This module contains the "cleaned" pieces of the AST, and the functions
13 use rustc_attr as attr;
14 use rustc_const_eval::const_eval::{is_const_fn, is_unstable_const_fn};
15 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
17 use rustc_hir::def::{CtorKind, DefKind, Res};
18 use rustc_hir::def_id::{DefId, CRATE_DEF_INDEX, LOCAL_CRATE};
19 use rustc_index::vec::{Idx, IndexVec};
20 use rustc_infer::infer::region_constraints::{Constraint, RegionConstraintData};
21 use rustc_middle::middle::resolve_lifetime as rl;
22 use rustc_middle::ty::fold::TypeFolder;
23 use rustc_middle::ty::subst::{InternalSubsts, Subst};
24 use rustc_middle::ty::{self, AdtKind, DefIdTree, Lift, Ty, TyCtxt};
25 use rustc_middle::{bug, span_bug};
26 use rustc_span::hygiene::{AstPass, MacroKind};
27 use rustc_span::symbol::{kw, sym, Ident, Symbol};
28 use rustc_span::{self, ExpnKind};
29 use rustc_target::spec::abi::Abi;
30 use rustc_typeck::check::intrinsic::intrinsic_operation_unsafety;
31 use rustc_typeck::hir_ty_to_ty;
33 use std::assert_matches::assert_matches;
34 use std::collections::hash_map::Entry;
35 use std::default::Default;
40 use crate::core::{self, DocContext, ImplTraitParam};
42 use crate::formats::item_type::ItemType;
46 crate use utils::{get_auto_trait_and_blanket_impls, krate, register_res};
48 crate use self::types::FnRetTy::*;
49 crate use self::types::ItemKind::*;
50 crate use self::types::SelfTy::*;
51 crate use self::types::Type::*;
52 crate use self::types::Visibility::{Inherited, Public};
53 crate use self::types::*;
55 crate trait Clean<T> {
56 fn clean(&self, cx: &mut DocContext<'_>) -> T;
59 impl<T: Clean<U>, U> Clean<Vec<U>> for [T] {
60 fn clean(&self, cx: &mut DocContext<'_>) -> Vec<U> {
61 self.iter().map(|x| x.clean(cx)).collect()
65 impl<T: Clean<U>, U, V: Idx> Clean<IndexVec<V, U>> for IndexVec<V, T> {
66 fn clean(&self, cx: &mut DocContext<'_>) -> IndexVec<V, U> {
67 self.iter().map(|x| x.clean(cx)).collect()
71 impl<T: Clean<U>, U> Clean<U> for &T {
72 fn clean(&self, cx: &mut DocContext<'_>) -> U {
77 impl<T: Clean<U>, U> Clean<U> for Rc<T> {
78 fn clean(&self, cx: &mut DocContext<'_>) -> U {
83 impl<T: Clean<U>, U> Clean<Option<U>> for Option<T> {
84 fn clean(&self, cx: &mut DocContext<'_>) -> Option<U> {
85 self.as_ref().map(|v| v.clean(cx))
89 impl Clean<Item> for doctree::Module<'_> {
90 fn clean(&self, cx: &mut DocContext<'_>) -> Item {
91 let mut items: Vec<Item> = vec![];
92 items.extend(self.foreigns.iter().map(|x| x.clean(cx)));
93 items.extend(self.mods.iter().map(|x| x.clean(cx)));
94 items.extend(self.items.iter().map(|x| x.clean(cx)).flatten());
96 // determine if we should display the inner contents or
97 // the outer `mod` item for the source code.
99 let span = Span::new({
100 let where_outer = self.where_outer(cx.tcx);
101 let sm = cx.sess().source_map();
102 let outer = sm.lookup_char_pos(where_outer.lo());
103 let inner = sm.lookup_char_pos(self.where_inner.lo());
104 if outer.file.start_pos == inner.file.start_pos {
108 // mod foo; (and a separate SourceFile for the contents)
113 Item::from_hir_id_and_parts(
116 ModuleItem(Module { items, span }),
122 impl Clean<Attributes> for [ast::Attribute] {
123 fn clean(&self, _cx: &mut DocContext<'_>) -> Attributes {
124 Attributes::from_ast(self, None)
128 impl Clean<GenericBound> for hir::GenericBound<'_> {
129 fn clean(&self, cx: &mut DocContext<'_>) -> GenericBound {
131 hir::GenericBound::Outlives(lt) => GenericBound::Outlives(lt.clean(cx)),
132 hir::GenericBound::LangItemTrait(lang_item, span, _, generic_args) => {
133 let def_id = cx.tcx.require_lang_item(lang_item, Some(span));
135 let trait_ref = ty::TraitRef::identity(cx.tcx, def_id).skip_binder();
137 let generic_args = generic_args.clean(cx);
138 let bindings = match generic_args {
139 GenericArgs::AngleBracketed { bindings, .. } => bindings,
140 _ => bug!("clean: parenthesized `GenericBound::LangItemTrait`"),
143 GenericBound::TraitBound(
144 PolyTrait { trait_: (trait_ref, &*bindings).clean(cx), generic_params: vec![] },
145 hir::TraitBoundModifier::None,
148 hir::GenericBound::Trait(ref t, modifier) => {
149 GenericBound::TraitBound(t.clean(cx), modifier)
155 impl Clean<Type> for (ty::TraitRef<'_>, &[TypeBinding]) {
156 fn clean(&self, cx: &mut DocContext<'_>) -> Type {
157 let (trait_ref, bounds) = *self;
158 let kind = cx.tcx.def_kind(trait_ref.def_id).into();
159 if !matches!(kind, ItemType::Trait | ItemType::TraitAlias) {
161 cx.tcx.def_span(trait_ref.def_id),
162 "`TraitRef` had unexpected kind {:?}",
166 inline::record_extern_fqn(cx, trait_ref.def_id, kind);
167 let path = external_path(cx, trait_ref.def_id, true, bounds.to_vec(), trait_ref.substs);
169 debug!("ty::TraitRef\n subst: {:?}\n", trait_ref.substs);
171 ResolvedPath { path, did: trait_ref.def_id, is_generic: false }
175 impl<'tcx> Clean<GenericBound> for ty::TraitRef<'tcx> {
176 fn clean(&self, cx: &mut DocContext<'_>) -> GenericBound {
177 GenericBound::TraitBound(
178 PolyTrait { trait_: (*self, &[][..]).clean(cx), generic_params: vec![] },
179 hir::TraitBoundModifier::None,
184 impl Clean<GenericBound> for (ty::PolyTraitRef<'_>, &[TypeBinding]) {
185 fn clean(&self, cx: &mut DocContext<'_>) -> GenericBound {
186 let (poly_trait_ref, bounds) = *self;
187 let poly_trait_ref = poly_trait_ref.lift_to_tcx(cx.tcx).unwrap();
189 // collect any late bound regions
190 let late_bound_regions: Vec<_> = cx
192 .collect_referenced_late_bound_regions(&poly_trait_ref)
194 .filter_map(|br| match br {
195 ty::BrNamed(_, name) => Some(GenericParamDef {
197 kind: GenericParamDefKind::Lifetime { outlives: vec![] },
203 GenericBound::TraitBound(
205 trait_: (poly_trait_ref.skip_binder(), bounds).clean(cx),
206 generic_params: late_bound_regions,
208 hir::TraitBoundModifier::None,
213 impl<'tcx> Clean<GenericBound> for ty::PolyTraitRef<'tcx> {
214 fn clean(&self, cx: &mut DocContext<'_>) -> GenericBound {
215 (*self, &[][..]).clean(cx)
219 impl Clean<Lifetime> for hir::Lifetime {
220 fn clean(&self, cx: &mut DocContext<'_>) -> Lifetime {
221 let def = cx.tcx.named_region(self.hir_id);
224 rl::Region::EarlyBound(_, node_id, _)
225 | rl::Region::LateBound(_, _, node_id, _)
226 | rl::Region::Free(_, node_id),
228 if let Some(lt) = cx.lt_substs.get(&node_id).cloned() {
234 Lifetime(self.name.ident().name)
238 impl Clean<Constant> for hir::ConstArg {
239 fn clean(&self, cx: &mut DocContext<'_>) -> Constant {
243 .type_of(cx.tcx.hir().body_owner_def_id(self.value.body).to_def_id())
245 kind: ConstantKind::Anonymous { body: self.value.body },
250 impl Clean<Option<Lifetime>> for ty::RegionKind {
251 fn clean(&self, _cx: &mut DocContext<'_>) -> Option<Lifetime> {
253 ty::ReStatic => Some(Lifetime::statik()),
254 ty::ReLateBound(_, ty::BoundRegion { kind: ty::BrNamed(_, name), .. }) => {
257 ty::ReEarlyBound(ref data) => Some(Lifetime(data.name)),
262 | ty::RePlaceholder(..)
265 debug!("cannot clean region {:?}", self);
272 impl Clean<WherePredicate> for hir::WherePredicate<'_> {
273 fn clean(&self, cx: &mut DocContext<'_>) -> WherePredicate {
275 hir::WherePredicate::BoundPredicate(ref wbp) => {
276 let bound_params = wbp
277 .bound_generic_params
280 // Higher-ranked params must be lifetimes.
281 // Higher-ranked lifetimes can't have bounds.
285 kind: hir::GenericParamKind::Lifetime { .. },
290 Lifetime(param.name.ident().name)
293 WherePredicate::BoundPredicate {
294 ty: wbp.bounded_ty.clean(cx),
295 bounds: wbp.bounds.clean(cx),
300 hir::WherePredicate::RegionPredicate(ref wrp) => WherePredicate::RegionPredicate {
301 lifetime: wrp.lifetime.clean(cx),
302 bounds: wrp.bounds.clean(cx),
305 hir::WherePredicate::EqPredicate(ref wrp) => {
306 WherePredicate::EqPredicate { lhs: wrp.lhs_ty.clean(cx), rhs: wrp.rhs_ty.clean(cx) }
312 impl<'a> Clean<Option<WherePredicate>> for ty::Predicate<'a> {
313 fn clean(&self, cx: &mut DocContext<'_>) -> Option<WherePredicate> {
314 let bound_predicate = self.kind();
315 match bound_predicate.skip_binder() {
316 ty::PredicateKind::Trait(pred) => Some(bound_predicate.rebind(pred).clean(cx)),
317 ty::PredicateKind::RegionOutlives(pred) => pred.clean(cx),
318 ty::PredicateKind::TypeOutlives(pred) => pred.clean(cx),
319 ty::PredicateKind::Projection(pred) => Some(pred.clean(cx)),
320 ty::PredicateKind::ConstEvaluatable(..) => None,
322 ty::PredicateKind::Subtype(..)
323 | ty::PredicateKind::Coerce(..)
324 | ty::PredicateKind::WellFormed(..)
325 | ty::PredicateKind::ObjectSafe(..)
326 | ty::PredicateKind::ClosureKind(..)
327 | ty::PredicateKind::ConstEquate(..)
328 | ty::PredicateKind::TypeWellFormedFromEnv(..) => panic!("not user writable"),
333 impl<'a> Clean<WherePredicate> for ty::PolyTraitPredicate<'a> {
334 fn clean(&self, cx: &mut DocContext<'_>) -> WherePredicate {
335 let poly_trait_ref = self.map_bound(|pred| pred.trait_ref);
336 WherePredicate::BoundPredicate {
337 ty: poly_trait_ref.skip_binder().self_ty().clean(cx),
338 bounds: vec![poly_trait_ref.clean(cx)],
339 bound_params: Vec::new(),
344 impl<'tcx> Clean<Option<WherePredicate>>
345 for ty::OutlivesPredicate<ty::Region<'tcx>, ty::Region<'tcx>>
347 fn clean(&self, cx: &mut DocContext<'_>) -> Option<WherePredicate> {
348 let ty::OutlivesPredicate(a, b) = self;
350 if let (ty::ReEmpty(_), ty::ReEmpty(_)) = (a, b) {
354 Some(WherePredicate::RegionPredicate {
355 lifetime: a.clean(cx).expect("failed to clean lifetime"),
356 bounds: vec![GenericBound::Outlives(b.clean(cx).expect("failed to clean bounds"))],
361 impl<'tcx> Clean<Option<WherePredicate>> for ty::OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>> {
362 fn clean(&self, cx: &mut DocContext<'_>) -> Option<WherePredicate> {
363 let ty::OutlivesPredicate(ty, lt) = self;
365 if let ty::ReEmpty(_) = lt {
369 Some(WherePredicate::BoundPredicate {
371 bounds: vec![GenericBound::Outlives(lt.clean(cx).expect("failed to clean lifetimes"))],
372 bound_params: Vec::new(),
377 impl<'tcx> Clean<WherePredicate> for ty::ProjectionPredicate<'tcx> {
378 fn clean(&self, cx: &mut DocContext<'_>) -> WherePredicate {
379 let ty::ProjectionPredicate { projection_ty, ty } = self;
380 WherePredicate::EqPredicate { lhs: projection_ty.clean(cx), rhs: ty.clean(cx) }
384 impl<'tcx> Clean<Type> for ty::ProjectionTy<'tcx> {
385 fn clean(&self, cx: &mut DocContext<'_>) -> Type {
386 let lifted = self.lift_to_tcx(cx.tcx).unwrap();
387 let trait_ = match lifted.trait_ref(cx.tcx).clean(cx) {
388 GenericBound::TraitBound(t, _) => t.trait_,
389 GenericBound::Outlives(_) => panic!("cleaning a trait got a lifetime"),
391 let self_type = self.self_ty().clean(cx);
393 name: cx.tcx.associated_item(self.item_def_id).ident.name,
394 self_def_id: self_type.def_id(),
395 self_type: box self_type,
401 impl Clean<GenericParamDef> for ty::GenericParamDef {
402 fn clean(&self, cx: &mut DocContext<'_>) -> GenericParamDef {
403 let (name, kind) = match self.kind {
404 ty::GenericParamDefKind::Lifetime => {
405 (self.name, GenericParamDefKind::Lifetime { outlives: vec![] })
407 ty::GenericParamDefKind::Type { has_default, synthetic, .. } => {
408 let default = if has_default {
409 let mut default = cx.tcx.type_of(self.def_id).clean(cx);
411 // We need to reassign the `self_def_id`, if there's a parent (which is the
412 // `Self` type), so we can properly render `<Self as X>` casts, because the
413 // information about which type `Self` is, is only present here, but not in
414 // the cleaning process of the type itself. To resolve this and have the
415 // `self_def_id` set, we override it here.
416 // See https://github.com/rust-lang/rust/issues/85454
417 if let QPath { ref mut self_def_id, .. } = default {
418 *self_def_id = cx.tcx.parent(self.def_id);
427 GenericParamDefKind::Type {
429 bounds: vec![], // These are filled in from the where-clauses.
435 ty::GenericParamDefKind::Const { has_default, .. } => (
437 GenericParamDefKind::Const {
439 ty: cx.tcx.type_of(self.def_id).clean(cx),
440 default: match has_default {
441 true => Some(cx.tcx.const_param_default(self.def_id).to_string()),
448 GenericParamDef { name, kind }
452 impl Clean<GenericParamDef> for hir::GenericParam<'_> {
453 fn clean(&self, cx: &mut DocContext<'_>) -> GenericParamDef {
454 let (name, kind) = match self.kind {
455 hir::GenericParamKind::Lifetime { .. } => {
459 .map(|bound| match bound {
460 hir::GenericBound::Outlives(lt) => lt.clean(cx),
464 (self.name.ident().name, GenericParamDefKind::Lifetime { outlives })
466 hir::GenericParamKind::Type { ref default, synthetic } => (
467 self.name.ident().name,
468 GenericParamDefKind::Type {
469 did: cx.tcx.hir().local_def_id(self.hir_id).to_def_id(),
470 bounds: self.bounds.clean(cx),
471 default: default.clean(cx),
475 hir::GenericParamKind::Const { ref ty, default } => (
476 self.name.ident().name,
477 GenericParamDefKind::Const {
478 did: cx.tcx.hir().local_def_id(self.hir_id).to_def_id(),
480 default: default.map(|ct| {
481 let def_id = cx.tcx.hir().local_def_id(ct.hir_id);
482 ty::Const::from_anon_const(cx.tcx, def_id).to_string()
488 GenericParamDef { name, kind }
492 impl Clean<Generics> for hir::Generics<'_> {
493 fn clean(&self, cx: &mut DocContext<'_>) -> Generics {
494 // Synthetic type-parameters are inserted after normal ones.
495 // In order for normal parameters to be able to refer to synthetic ones,
497 fn is_impl_trait(param: &hir::GenericParam<'_>) -> bool {
499 hir::GenericParamKind::Type { synthetic, .. } => {
500 synthetic == Some(hir::SyntheticTyParamKind::ImplTrait)
505 /// This can happen for `async fn`, e.g. `async fn f<'_>(&'_ self)`.
507 /// See [`lifetime_to_generic_param`] in [`rustc_ast_lowering`] for more information.
509 /// [`lifetime_to_generic_param`]: rustc_ast_lowering::LoweringContext::lifetime_to_generic_param
510 fn is_elided_lifetime(param: &hir::GenericParam<'_>) -> bool {
513 hir::GenericParamKind::Lifetime { kind: hir::LifetimeParamKind::Elided }
517 let impl_trait_params = self
520 .filter(|param| is_impl_trait(param))
522 let param: GenericParamDef = param.clean(cx);
524 GenericParamDefKind::Lifetime { .. } => unreachable!(),
525 GenericParamDefKind::Type { did, ref bounds, .. } => {
526 cx.impl_trait_bounds.insert(did.into(), bounds.clone());
528 GenericParamDefKind::Const { .. } => unreachable!(),
532 .collect::<Vec<_>>();
534 let mut params = Vec::with_capacity(self.params.len());
535 for p in self.params.iter().filter(|p| !is_impl_trait(p) && !is_elided_lifetime(p)) {
539 params.extend(impl_trait_params);
542 Generics { params, where_predicates: self.where_clause.predicates.clean(cx) };
544 // Some duplicates are generated for ?Sized bounds between type params and where
545 // predicates. The point in here is to move the bounds definitions from type params
546 // to where predicates when such cases occur.
547 for where_pred in &mut generics.where_predicates {
549 WherePredicate::BoundPredicate {
550 ty: Generic(ref name), ref mut bounds, ..
552 if bounds.is_empty() {
553 for param in &mut generics.params {
555 GenericParamDefKind::Lifetime { .. } => {}
556 GenericParamDefKind::Type { bounds: ref mut ty_bounds, .. } => {
557 if ¶m.name == name {
558 mem::swap(bounds, ty_bounds);
562 GenericParamDefKind::Const { .. } => {}
574 impl<'a, 'tcx> Clean<Generics> for (&'a ty::Generics, ty::GenericPredicates<'tcx>) {
575 fn clean(&self, cx: &mut DocContext<'_>) -> Generics {
576 use self::WherePredicate as WP;
577 use std::collections::BTreeMap;
579 let (gens, preds) = *self;
581 // Don't populate `cx.impl_trait_bounds` before `clean`ning `where` clauses,
582 // since `Clean for ty::Predicate` would consume them.
583 let mut impl_trait = BTreeMap::<ImplTraitParam, Vec<GenericBound>>::default();
585 // Bounds in the type_params and lifetimes fields are repeated in the
586 // predicates field (see rustc_typeck::collect::ty_generics), so remove
588 let stripped_params = gens
591 .filter_map(|param| match param.kind {
592 ty::GenericParamDefKind::Lifetime => Some(param.clean(cx)),
593 ty::GenericParamDefKind::Type { synthetic, .. } => {
594 if param.name == kw::SelfUpper {
595 assert_eq!(param.index, 0);
598 if synthetic == Some(hir::SyntheticTyParamKind::ImplTrait) {
599 impl_trait.insert(param.index.into(), vec![]);
602 Some(param.clean(cx))
604 ty::GenericParamDefKind::Const { .. } => Some(param.clean(cx)),
606 .collect::<Vec<GenericParamDef>>();
608 // param index -> [(DefId of trait, associated type name, type)]
609 let mut impl_trait_proj = FxHashMap::<u32, Vec<(DefId, Symbol, Ty<'tcx>)>>::default();
611 let where_predicates = preds
615 let mut projection = None;
616 let param_idx = (|| {
617 let bound_p = p.kind();
618 match bound_p.skip_binder() {
619 ty::PredicateKind::Trait(pred) => {
620 if let ty::Param(param) = pred.self_ty().kind() {
621 return Some(param.index);
624 ty::PredicateKind::TypeOutlives(ty::OutlivesPredicate(ty, _reg)) => {
625 if let ty::Param(param) = ty.kind() {
626 return Some(param.index);
629 ty::PredicateKind::Projection(p) => {
630 if let ty::Param(param) = p.projection_ty.self_ty().kind() {
631 projection = Some(bound_p.rebind(p));
632 return Some(param.index);
641 if let Some(param_idx) = param_idx {
642 if let Some(b) = impl_trait.get_mut(¶m_idx.into()) {
643 let p = p.clean(cx)?;
650 .filter(|b| !b.is_sized_bound(cx)),
653 let proj = projection
654 .map(|p| (p.skip_binder().projection_ty.clean(cx), p.skip_binder().ty));
655 if let Some(((_, trait_did, name), rhs)) =
656 proj.as_ref().and_then(|(lhs, rhs)| Some((lhs.projection()?, rhs)))
661 .push((trait_did, name, rhs));
670 .collect::<Vec<_>>();
672 for (param, mut bounds) in impl_trait {
673 // Move trait bounds to the front.
674 bounds.sort_by_key(|b| !matches!(b, GenericBound::TraitBound(..)));
676 if let crate::core::ImplTraitParam::ParamIndex(idx) = param {
677 if let Some(proj) = impl_trait_proj.remove(&idx) {
678 for (trait_did, name, rhs) in proj {
679 let rhs = rhs.clean(cx);
680 simplify::merge_bounds(cx, &mut bounds, trait_did, name, &rhs);
687 cx.impl_trait_bounds.insert(param, bounds);
690 // Now that `cx.impl_trait_bounds` is populated, we can process
691 // remaining predicates which could contain `impl Trait`.
692 let mut where_predicates =
693 where_predicates.into_iter().flat_map(|p| p.clean(cx)).collect::<Vec<_>>();
695 // Type parameters have a Sized bound by default unless removed with
696 // ?Sized. Scan through the predicates and mark any type parameter with
697 // a Sized bound, removing the bounds as we find them.
699 // Note that associated types also have a sized bound by default, but we
700 // don't actually know the set of associated types right here so that's
701 // handled in cleaning associated types
702 let mut sized_params = FxHashSet::default();
703 where_predicates.retain(|pred| match *pred {
704 WP::BoundPredicate { ty: Generic(ref g), ref bounds, .. } => {
705 if bounds.iter().any(|b| b.is_sized_bound(cx)) {
706 sized_params.insert(*g);
715 // Run through the type parameters again and insert a ?Sized
716 // unbound for any we didn't find to be Sized.
717 for tp in &stripped_params {
718 if matches!(tp.kind, types::GenericParamDefKind::Type { .. })
719 && !sized_params.contains(&tp.name)
721 where_predicates.push(WP::BoundPredicate {
722 ty: Type::Generic(tp.name),
723 bounds: vec![GenericBound::maybe_sized(cx)],
724 bound_params: Vec::new(),
729 // It would be nice to collect all of the bounds on a type and recombine
730 // them if possible, to avoid e.g., `where T: Foo, T: Bar, T: Sized, T: 'a`
731 // and instead see `where T: Foo + Bar + Sized + 'a`
734 params: stripped_params,
735 where_predicates: simplify::where_clauses(cx, where_predicates),
740 fn clean_fn_or_proc_macro(
741 item: &hir::Item<'_>,
742 sig: &'a hir::FnSig<'a>,
743 generics: &'a hir::Generics<'a>,
744 body_id: hir::BodyId,
746 cx: &mut DocContext<'_>,
748 let attrs = cx.tcx.hir().attrs(item.hir_id());
749 let macro_kind = attrs.iter().find_map(|a| {
750 if a.has_name(sym::proc_macro) {
751 Some(MacroKind::Bang)
752 } else if a.has_name(sym::proc_macro_derive) {
753 Some(MacroKind::Derive)
754 } else if a.has_name(sym::proc_macro_attribute) {
755 Some(MacroKind::Attr)
762 if kind == MacroKind::Derive {
764 .lists(sym::proc_macro_derive)
765 .find_map(|mi| mi.ident())
766 .expect("proc-macro derives require a name")
770 let mut helpers = Vec::new();
771 for mi in attrs.lists(sym::proc_macro_derive) {
772 if !mi.has_name(sym::attributes) {
776 if let Some(list) = mi.meta_item_list() {
777 for inner_mi in list {
778 if let Some(ident) = inner_mi.ident() {
779 helpers.push(ident.name);
784 ProcMacroItem(ProcMacro { kind, helpers })
787 let mut func = (sig, generics, body_id).clean(cx);
788 let def_id = item.def_id.to_def_id();
789 func.header.constness =
790 if is_const_fn(cx.tcx, def_id) && is_unstable_const_fn(cx.tcx, def_id).is_none() {
791 hir::Constness::Const
793 hir::Constness::NotConst
800 impl<'a> Clean<Function> for (&'a hir::FnSig<'a>, &'a hir::Generics<'a>, hir::BodyId) {
801 fn clean(&self, cx: &mut DocContext<'_>) -> Function {
802 let (generics, decl) =
803 enter_impl_trait(cx, |cx| (self.1.clean(cx), (&*self.0.decl, self.2).clean(cx)));
804 Function { decl, generics, header: self.0.header }
808 impl<'a> Clean<Arguments> for (&'a [hir::Ty<'a>], &'a [Ident]) {
809 fn clean(&self, cx: &mut DocContext<'_>) -> Arguments {
816 let mut name = self.1.get(i).map_or(kw::Empty, |ident| ident.name);
818 name = kw::Underscore;
820 Argument { name, type_: ty.clean(cx) }
827 impl<'a> Clean<Arguments> for (&'a [hir::Ty<'a>], hir::BodyId) {
828 fn clean(&self, cx: &mut DocContext<'_>) -> Arguments {
829 let body = cx.tcx.hir().body(self.1);
836 .map(|(i, ty)| Argument {
837 name: name_from_pat(&body.params[i].pat),
845 impl<'a, A: Copy> Clean<FnDecl> for (&'a hir::FnDecl<'a>, A)
847 (&'a [hir::Ty<'a>], A): Clean<Arguments>,
849 fn clean(&self, cx: &mut DocContext<'_>) -> FnDecl {
851 inputs: (self.0.inputs, self.1).clean(cx),
852 output: self.0.output.clean(cx),
853 c_variadic: self.0.c_variadic,
858 impl<'tcx> Clean<FnDecl> for (DefId, ty::PolyFnSig<'tcx>) {
859 fn clean(&self, cx: &mut DocContext<'_>) -> FnDecl {
860 let (did, sig) = *self;
861 let mut names = if did.is_local() { &[] } else { cx.tcx.fn_arg_names(did) }.iter();
864 output: Return(sig.skip_binder().output().clean(cx)),
865 c_variadic: sig.skip_binder().c_variadic,
873 name: names.next().map_or(kw::Empty, |i| i.name),
881 impl Clean<FnRetTy> for hir::FnRetTy<'_> {
882 fn clean(&self, cx: &mut DocContext<'_>) -> FnRetTy {
884 Self::Return(ref typ) => Return(typ.clean(cx)),
885 Self::DefaultReturn(..) => DefaultReturn,
890 impl Clean<bool> for hir::IsAuto {
891 fn clean(&self, _: &mut DocContext<'_>) -> bool {
893 hir::IsAuto::Yes => true,
894 hir::IsAuto::No => false,
899 impl Clean<Type> for hir::TraitRef<'_> {
900 fn clean(&self, cx: &mut DocContext<'_>) -> Type {
901 let path = self.path.clean(cx);
902 resolve_type(cx, path)
906 impl Clean<PolyTrait> for hir::PolyTraitRef<'_> {
907 fn clean(&self, cx: &mut DocContext<'_>) -> PolyTrait {
909 trait_: self.trait_ref.clean(cx),
910 generic_params: self.bound_generic_params.clean(cx),
915 impl Clean<Item> for hir::TraitItem<'_> {
916 fn clean(&self, cx: &mut DocContext<'_>) -> Item {
917 let local_did = self.def_id.to_def_id();
918 cx.with_param_env(local_did, |cx| {
919 let inner = match self.kind {
920 hir::TraitItemKind::Const(ref ty, default) => {
921 AssocConstItem(ty.clean(cx), default.map(|e| print_const_expr(cx.tcx, e)))
923 hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Provided(body)) => {
924 let mut m = (sig, &self.generics, body).clean(cx);
925 if m.header.constness == hir::Constness::Const
926 && is_unstable_const_fn(cx.tcx, local_did).is_some()
928 m.header.constness = hir::Constness::NotConst;
932 hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Required(ref names)) => {
933 let (generics, decl) = enter_impl_trait(cx, |cx| {
934 (self.generics.clean(cx), (&*sig.decl, &names[..]).clean(cx))
936 let mut t = Function { header: sig.header, decl, generics };
937 if t.header.constness == hir::Constness::Const
938 && is_unstable_const_fn(cx.tcx, local_did).is_some()
940 t.header.constness = hir::Constness::NotConst;
944 hir::TraitItemKind::Type(ref bounds, ref default) => {
945 AssocTypeItem(bounds.clean(cx), default.clean(cx))
948 let what_rustc_thinks =
949 Item::from_def_id_and_parts(local_did, Some(self.ident.name), inner, cx);
950 // Trait items always inherit the trait's visibility -- we don't want to show `pub`.
951 Item { visibility: Inherited, ..what_rustc_thinks }
956 impl Clean<Item> for hir::ImplItem<'_> {
957 fn clean(&self, cx: &mut DocContext<'_>) -> Item {
958 let local_did = self.def_id.to_def_id();
959 cx.with_param_env(local_did, |cx| {
960 let inner = match self.kind {
961 hir::ImplItemKind::Const(ref ty, expr) => {
962 AssocConstItem(ty.clean(cx), Some(print_const_expr(cx.tcx, expr)))
964 hir::ImplItemKind::Fn(ref sig, body) => {
965 let mut m = (sig, &self.generics, body).clean(cx);
966 if m.header.constness == hir::Constness::Const
967 && is_unstable_const_fn(cx.tcx, local_did).is_some()
969 m.header.constness = hir::Constness::NotConst;
971 MethodItem(m, Some(self.defaultness))
973 hir::ImplItemKind::TyAlias(ref hir_ty) => {
974 let type_ = hir_ty.clean(cx);
975 let item_type = hir_ty_to_ty(cx.tcx, hir_ty).clean(cx);
979 generics: Generics::default(),
980 item_type: Some(item_type),
987 let what_rustc_thinks =
988 Item::from_def_id_and_parts(local_did, Some(self.ident.name), inner, cx);
989 let parent_item = cx.tcx.hir().expect_item(cx.tcx.hir().get_parent_item(self.hir_id()));
990 if let hir::ItemKind::Impl(impl_) = &parent_item.kind {
991 if impl_.of_trait.is_some() {
992 // Trait impl items always inherit the impl's visibility --
993 // we don't want to show `pub`.
994 Item { visibility: Inherited, ..what_rustc_thinks }
999 panic!("found impl item with non-impl parent {:?}", parent_item);
1005 impl Clean<Item> for ty::AssocItem {
1006 fn clean(&self, cx: &mut DocContext<'_>) -> Item {
1008 let kind = match self.kind {
1009 ty::AssocKind::Const => {
1010 let ty = tcx.type_of(self.def_id);
1011 let default = if self.defaultness.has_value() {
1012 Some(inline::print_inlined_const(tcx, self.def_id))
1016 AssocConstItem(ty.clean(cx), default)
1018 ty::AssocKind::Fn => {
1020 (tcx.generics_of(self.def_id), tcx.explicit_predicates_of(self.def_id))
1022 let sig = tcx.fn_sig(self.def_id);
1023 let mut decl = (self.def_id, sig).clean(cx);
1025 if self.fn_has_self_parameter {
1026 let self_ty = match self.container {
1027 ty::ImplContainer(def_id) => tcx.type_of(def_id),
1028 ty::TraitContainer(_) => tcx.types.self_param,
1030 let self_arg_ty = sig.input(0).skip_binder();
1031 if self_arg_ty == self_ty {
1032 decl.inputs.values[0].type_ = Generic(kw::SelfUpper);
1033 } else if let ty::Ref(_, ty, _) = *self_arg_ty.kind() {
1035 match decl.inputs.values[0].type_ {
1036 BorrowedRef { ref mut type_, .. } => {
1037 **type_ = Generic(kw::SelfUpper)
1039 _ => unreachable!(),
1045 let provided = match self.container {
1046 ty::ImplContainer(_) => true,
1047 ty::TraitContainer(_) => self.defaultness.has_value(),
1050 let constness = if tcx.is_const_fn_raw(self.def_id) {
1051 hir::Constness::Const
1053 hir::Constness::NotConst
1055 let asyncness = tcx.asyncness(self.def_id);
1056 let defaultness = match self.container {
1057 ty::ImplContainer(_) => Some(self.defaultness),
1058 ty::TraitContainer(_) => None,
1064 header: hir::FnHeader {
1065 unsafety: sig.unsafety(),
1074 TyMethodItem(Function {
1077 header: hir::FnHeader {
1078 unsafety: sig.unsafety(),
1080 constness: hir::Constness::NotConst,
1081 asyncness: hir::IsAsync::NotAsync,
1086 ty::AssocKind::Type => {
1087 let my_name = self.ident.name;
1089 if let ty::TraitContainer(_) = self.container {
1090 let bounds = tcx.explicit_item_bounds(self.def_id);
1091 let predicates = ty::GenericPredicates { parent: None, predicates: bounds };
1092 let generics = (tcx.generics_of(self.def_id), predicates).clean(cx);
1093 let mut bounds = generics
1096 .filter_map(|pred| {
1097 let (name, self_type, trait_, bounds) = match *pred {
1098 WherePredicate::BoundPredicate {
1099 ty: QPath { ref name, ref self_type, ref trait_, .. },
1102 } => (name, self_type, trait_, bounds),
1105 if *name != my_name {
1109 ResolvedPath { did, .. } if did == self.container.id() => {}
1113 Generic(ref s) if *s == kw::SelfUpper => {}
1118 .flat_map(|i| i.iter().cloned())
1119 .collect::<Vec<_>>();
1120 // Our Sized/?Sized bound didn't get handled when creating the generics
1121 // because we didn't actually get our whole set of bounds until just now
1122 // (some of them may have come from the trait). If we do have a sized
1123 // bound, we remove it, and if we don't then we add the `?Sized` bound
1125 match bounds.iter().position(|b| b.is_sized_bound(cx)) {
1129 None => bounds.push(GenericBound::maybe_sized(cx)),
1132 let ty = if self.defaultness.has_value() {
1133 Some(tcx.type_of(self.def_id))
1138 AssocTypeItem(bounds, ty.clean(cx))
1140 // FIXME: when could this happen? Associated items in inherent impls?
1141 let type_ = tcx.type_of(self.def_id).clean(cx);
1145 generics: Generics { params: Vec::new(), where_predicates: Vec::new() },
1154 Item::from_def_id_and_parts(self.def_id, Some(self.ident.name), kind, cx)
1158 fn clean_qpath(hir_ty: &hir::Ty<'_>, cx: &mut DocContext<'_>) -> Type {
1159 use rustc_hir::GenericParamCount;
1160 let hir::Ty { hir_id: _, span, ref kind } = *hir_ty;
1161 let qpath = match kind {
1162 hir::TyKind::Path(qpath) => qpath,
1163 _ => unreachable!(),
1167 hir::QPath::Resolved(None, ref path) => {
1168 if let Res::Def(DefKind::TyParam, did) = path.res {
1169 if let Some(new_ty) = cx.ty_substs.get(&did).cloned() {
1172 if let Some(bounds) = cx.impl_trait_bounds.remove(&did.into()) {
1173 return ImplTrait(bounds);
1177 let mut alias = None;
1178 if let Res::Def(DefKind::TyAlias, def_id) = path.res {
1179 // Substitute private type aliases
1180 if let Some(def_id) = def_id.as_local() {
1181 let hir_id = cx.tcx.hir().local_def_id_to_hir_id(def_id);
1182 if !cx.cache.access_levels.is_exported(def_id.to_def_id()) {
1183 alias = Some(&cx.tcx.hir().expect_item(hir_id).kind);
1188 if let Some(&hir::ItemKind::TyAlias(ref ty, ref generics)) = alias {
1189 let provided_params = &path.segments.last().expect("segments were empty");
1190 let mut ty_substs = FxHashMap::default();
1191 let mut lt_substs = FxHashMap::default();
1192 let mut ct_substs = FxHashMap::default();
1193 let generic_args = provided_params.args();
1195 let mut indices: GenericParamCount = Default::default();
1196 for param in generics.params.iter() {
1198 hir::GenericParamKind::Lifetime { .. } => {
1200 let lifetime = generic_args.args.iter().find_map(|arg| match arg {
1201 hir::GenericArg::Lifetime(lt) => {
1202 if indices.lifetimes == j {
1210 if let Some(lt) = lifetime.cloned() {
1211 let lt_def_id = cx.tcx.hir().local_def_id(param.hir_id);
1212 let cleaned = if !lt.is_elided() {
1215 self::types::Lifetime::elided()
1217 lt_substs.insert(lt_def_id.to_def_id(), cleaned);
1219 indices.lifetimes += 1;
1221 hir::GenericParamKind::Type { ref default, .. } => {
1222 let ty_param_def_id = cx.tcx.hir().local_def_id(param.hir_id);
1224 let type_ = generic_args.args.iter().find_map(|arg| match arg {
1225 hir::GenericArg::Type(ty) => {
1226 if indices.types == j {
1234 if let Some(ty) = type_ {
1235 ty_substs.insert(ty_param_def_id.to_def_id(), ty.clean(cx));
1236 } else if let Some(default) = *default {
1238 .insert(ty_param_def_id.to_def_id(), default.clean(cx));
1242 hir::GenericParamKind::Const { .. } => {
1243 let const_param_def_id = cx.tcx.hir().local_def_id(param.hir_id);
1245 let const_ = generic_args.args.iter().find_map(|arg| match arg {
1246 hir::GenericArg::Const(ct) => {
1247 if indices.consts == j {
1255 if let Some(ct) = const_ {
1256 ct_substs.insert(const_param_def_id.to_def_id(), ct.clean(cx));
1258 // FIXME(const_generics_defaults)
1259 indices.consts += 1;
1264 return cx.enter_alias(ty_substs, lt_substs, ct_substs, |cx| ty.clean(cx));
1266 let path = path.clean(cx);
1267 resolve_type(cx, path)
1269 hir::QPath::Resolved(Some(ref qself), ref p) => {
1270 // Try to normalize `<X as Y>::T` to a type
1271 let ty = hir_ty_to_ty(cx.tcx, hir_ty);
1272 if let Some(normalized_value) = normalize(cx, ty) {
1273 return normalized_value.clean(cx);
1276 let segments = if p.is_global() { &p.segments[1..] } else { &p.segments };
1277 let trait_segments = &segments[..segments.len() - 1];
1278 let trait_def = cx.tcx.associated_item(p.res.def_id()).container.id();
1279 let trait_path = self::Path {
1280 global: p.is_global(),
1281 res: Res::Def(DefKind::Trait, trait_def),
1282 segments: trait_segments.clean(cx),
1285 name: p.segments.last().expect("segments were empty").ident.name,
1286 self_def_id: Some(DefId::local(qself.hir_id.owner.local_def_index)),
1287 self_type: box qself.clean(cx),
1288 trait_: box resolve_type(cx, trait_path),
1291 hir::QPath::TypeRelative(ref qself, ref segment) => {
1292 let ty = hir_ty_to_ty(cx.tcx, hir_ty);
1293 let res = match ty.kind() {
1294 ty::Projection(proj) => Res::Def(DefKind::Trait, proj.trait_ref(cx.tcx).def_id),
1295 // Rustdoc handles `ty::Error`s by turning them into `Type::Infer`s.
1296 ty::Error(_) => return Type::Infer,
1297 _ => bug!("clean: expected associated type, found `{:?}`", ty),
1299 let trait_path = hir::Path { span, res, segments: &[] }.clean(cx);
1301 name: segment.ident.name,
1302 self_def_id: res.opt_def_id(),
1303 self_type: box qself.clean(cx),
1304 trait_: box resolve_type(cx, trait_path),
1307 hir::QPath::LangItem(..) => bug!("clean: requiring documentation of lang item"),
1311 impl Clean<Type> for hir::Ty<'_> {
1312 fn clean(&self, cx: &mut DocContext<'_>) -> Type {
1316 TyKind::Never => Never,
1317 TyKind::Ptr(ref m) => RawPointer(m.mutbl, box m.ty.clean(cx)),
1318 TyKind::Rptr(ref l, ref m) => {
1319 // There are two times a `Fresh` lifetime can be created:
1320 // 1. For `&'_ x`, written by the user. This corresponds to `lower_lifetime` in `rustc_ast_lowering`.
1321 // 2. For `&x` as a parameter to an `async fn`. This corresponds to `elided_ref_lifetime in `rustc_ast_lowering`.
1322 // See #59286 for more information.
1323 // Ideally we would only hide the `'_` for case 2., but I don't know a way to distinguish it.
1324 // Turning `fn f(&'_ self)` into `fn f(&self)` isn't the worst thing in the world, though;
1325 // there's no case where it could cause the function to fail to compile.
1327 l.is_elided() || matches!(l.name, LifetimeName::Param(ParamName::Fresh(_)));
1328 let lifetime = if elided { None } else { Some(l.clean(cx)) };
1329 BorrowedRef { lifetime, mutability: m.mutbl, type_: box m.ty.clean(cx) }
1331 TyKind::Slice(ref ty) => Slice(box ty.clean(cx)),
1332 TyKind::Array(ref ty, ref length) => {
1333 let def_id = cx.tcx.hir().local_def_id(length.hir_id);
1334 // NOTE(min_const_generics): We can't use `const_eval_poly` for constants
1335 // as we currently do not supply the parent generics to anonymous constants
1336 // but do allow `ConstKind::Param`.
1338 // `const_eval_poly` tries to to first substitute generic parameters which
1339 // results in an ICE while manually constructing the constant and using `eval`
1340 // does nothing for `ConstKind::Param`.
1341 let ct = ty::Const::from_anon_const(cx.tcx, def_id);
1342 let param_env = cx.tcx.param_env(def_id);
1343 let length = print_const(cx, ct.eval(cx.tcx, param_env));
1344 Array(box ty.clean(cx), length)
1346 TyKind::Tup(ref tys) => Tuple(tys.clean(cx)),
1347 TyKind::OpaqueDef(item_id, _) => {
1348 let item = cx.tcx.hir().item(item_id);
1349 if let hir::ItemKind::OpaqueTy(ref ty) = item.kind {
1350 ImplTrait(ty.bounds.clean(cx))
1355 TyKind::Path(_) => clean_qpath(&self, cx),
1356 TyKind::TraitObject(ref bounds, ref lifetime, _) => {
1357 let bounds = bounds.iter().map(|bound| bound.clean(cx)).collect();
1358 let lifetime = if !lifetime.is_elided() { Some(lifetime.clean(cx)) } else { None };
1359 DynTrait(bounds, lifetime)
1361 TyKind::BareFn(ref barefn) => BareFunction(box barefn.clean(cx)),
1362 // Rustdoc handles `TyKind::Err`s by turning them into `Type::Infer`s.
1363 TyKind::Infer | TyKind::Err => Infer,
1364 TyKind::Typeof(..) => panic!("unimplemented type {:?}", self.kind),
1369 /// Returns `None` if the type could not be normalized
1370 fn normalize(cx: &mut DocContext<'tcx>, ty: Ty<'_>) -> Option<Ty<'tcx>> {
1371 // HACK: low-churn fix for #79459 while we wait for a trait normalization fix
1372 if !cx.tcx.sess.opts.debugging_opts.normalize_docs {
1376 use crate::rustc_trait_selection::infer::TyCtxtInferExt;
1377 use crate::rustc_trait_selection::traits::query::normalize::AtExt;
1378 use rustc_middle::traits::ObligationCause;
1380 // Try to normalize `<X as Y>::T` to a type
1381 let lifted = ty.lift_to_tcx(cx.tcx).unwrap();
1382 let normalized = cx.tcx.infer_ctxt().enter(|infcx| {
1384 .at(&ObligationCause::dummy(), cx.param_env)
1386 .map(|resolved| infcx.resolve_vars_if_possible(resolved.value))
1389 Ok(normalized_value) => {
1390 debug!("normalized {:?} to {:?}", ty, normalized_value);
1391 Some(normalized_value)
1394 debug!("failed to normalize {:?}: {:?}", ty, err);
1400 impl<'tcx> Clean<Type> for Ty<'tcx> {
1401 fn clean(&self, cx: &mut DocContext<'_>) -> Type {
1402 trace!("cleaning type: {:?}", self);
1403 let ty = normalize(cx, self).unwrap_or(self);
1406 ty::Bool => Primitive(PrimitiveType::Bool),
1407 ty::Char => Primitive(PrimitiveType::Char),
1408 ty::Int(int_ty) => Primitive(int_ty.into()),
1409 ty::Uint(uint_ty) => Primitive(uint_ty.into()),
1410 ty::Float(float_ty) => Primitive(float_ty.into()),
1411 ty::Str => Primitive(PrimitiveType::Str),
1412 ty::Slice(ty) => Slice(box ty.clean(cx)),
1413 ty::Array(ty, n) => {
1414 let mut n = cx.tcx.lift(n).expect("array lift failed");
1415 n = n.eval(cx.tcx, ty::ParamEnv::reveal_all());
1416 let n = print_const(cx, n);
1417 Array(box ty.clean(cx), n)
1419 ty::RawPtr(mt) => RawPointer(mt.mutbl, box mt.ty.clean(cx)),
1420 ty::Ref(r, ty, mutbl) => {
1421 BorrowedRef { lifetime: r.clean(cx), mutability: mutbl, type_: box ty.clean(cx) }
1423 ty::FnDef(..) | ty::FnPtr(_) => {
1424 let ty = cx.tcx.lift(*self).expect("FnPtr lift failed");
1425 let sig = ty.fn_sig(cx.tcx);
1426 let def_id = DefId::local(CRATE_DEF_INDEX);
1427 BareFunction(box BareFunctionDecl {
1428 unsafety: sig.unsafety(),
1429 generic_params: Vec::new(),
1430 decl: (def_id, sig).clean(cx),
1434 ty::Adt(def, substs) => {
1436 let kind = match def.adt_kind() {
1437 AdtKind::Struct => ItemType::Struct,
1438 AdtKind::Union => ItemType::Union,
1439 AdtKind::Enum => ItemType::Enum,
1441 inline::record_extern_fqn(cx, did, kind);
1442 let path = external_path(cx, did, false, vec![], substs);
1443 ResolvedPath { path, did, is_generic: false }
1445 ty::Foreign(did) => {
1446 inline::record_extern_fqn(cx, did, ItemType::ForeignType);
1447 let path = external_path(cx, did, false, vec![], InternalSubsts::empty());
1448 ResolvedPath { path, did, is_generic: false }
1450 ty::Dynamic(ref obj, ref reg) => {
1451 // HACK: pick the first `did` as the `did` of the trait object. Someone
1452 // might want to implement "native" support for marker-trait-only
1454 let mut dids = obj.principal_def_id().into_iter().chain(obj.auto_traits());
1457 .unwrap_or_else(|| panic!("found trait object `{:?}` with no traits?", self));
1458 let substs = match obj.principal() {
1459 Some(principal) => principal.skip_binder().substs,
1460 // marker traits have no substs.
1461 _ => cx.tcx.intern_substs(&[]),
1464 inline::record_extern_fqn(cx, did, ItemType::Trait);
1466 let lifetime = reg.clean(cx);
1467 let mut bounds = vec![];
1470 let empty = cx.tcx.intern_substs(&[]);
1471 let path = external_path(cx, did, false, vec![], empty);
1472 inline::record_extern_fqn(cx, did, ItemType::Trait);
1473 let bound = PolyTrait {
1474 trait_: ResolvedPath { path, did, is_generic: false },
1475 generic_params: Vec::new(),
1480 let mut bindings = vec![];
1481 for pb in obj.projection_bounds() {
1482 bindings.push(TypeBinding {
1483 name: cx.tcx.associated_item(pb.item_def_id()).ident.name,
1484 kind: TypeBindingKind::Equality { ty: pb.skip_binder().ty.clean(cx) },
1488 let path = external_path(cx, did, false, bindings, substs);
1492 trait_: ResolvedPath { path, did, is_generic: false },
1493 generic_params: Vec::new(),
1497 DynTrait(bounds, lifetime)
1499 ty::Tuple(ref t) => {
1500 Tuple(t.iter().map(|t| t.expect_ty()).collect::<Vec<_>>().clean(cx))
1503 ty::Projection(ref data) => data.clean(cx),
1505 ty::Param(ref p) => {
1506 if let Some(bounds) = cx.impl_trait_bounds.remove(&p.index.into()) {
1513 ty::Opaque(def_id, substs) => {
1514 // Grab the "TraitA + TraitB" from `impl TraitA + TraitB`,
1515 // by looking up the bounds associated with the def_id.
1516 let substs = cx.tcx.lift(substs).expect("Opaque lift failed");
1519 .explicit_item_bounds(def_id)
1521 .map(|(bound, _)| bound.subst(cx.tcx, substs))
1522 .collect::<Vec<_>>();
1523 let mut regions = vec![];
1524 let mut has_sized = false;
1525 let mut bounds = bounds
1527 .filter_map(|bound| {
1528 let bound_predicate = bound.kind();
1529 let trait_ref = match bound_predicate.skip_binder() {
1530 ty::PredicateKind::Trait(tr) => bound_predicate.rebind(tr.trait_ref),
1531 ty::PredicateKind::TypeOutlives(ty::OutlivesPredicate(_ty, reg)) => {
1532 if let Some(r) = reg.clean(cx) {
1533 regions.push(GenericBound::Outlives(r));
1540 if let Some(sized) = cx.tcx.lang_items().sized_trait() {
1541 if trait_ref.def_id() == sized {
1547 let bounds: Vec<_> = bounds
1549 .filter_map(|bound| {
1550 if let ty::PredicateKind::Projection(proj) =
1551 bound.kind().skip_binder()
1553 if proj.projection_ty.trait_ref(cx.tcx)
1554 == trait_ref.skip_binder()
1559 .associated_item(proj.projection_ty.item_def_id)
1562 kind: TypeBindingKind::Equality {
1563 ty: proj.ty.clean(cx),
1575 Some((trait_ref, &bounds[..]).clean(cx))
1577 .collect::<Vec<_>>();
1578 bounds.extend(regions);
1579 if !has_sized && !bounds.is_empty() {
1580 bounds.insert(0, GenericBound::maybe_sized(cx));
1585 ty::Closure(..) | ty::Generator(..) => Tuple(vec![]), // FIXME(pcwalton)
1587 ty::Bound(..) => panic!("Bound"),
1588 ty::Placeholder(..) => panic!("Placeholder"),
1589 ty::GeneratorWitness(..) => panic!("GeneratorWitness"),
1590 ty::Infer(..) => panic!("Infer"),
1591 ty::Error(_) => panic!("Error"),
1596 impl<'tcx> Clean<Constant> for ty::Const<'tcx> {
1597 fn clean(&self, cx: &mut DocContext<'_>) -> Constant {
1598 // FIXME: instead of storing the stringified expression, store `self` directly instead.
1600 type_: self.ty.clean(cx),
1601 kind: ConstantKind::TyConst { expr: self.to_string() },
1606 impl Clean<Item> for hir::FieldDef<'_> {
1607 fn clean(&self, cx: &mut DocContext<'_>) -> Item {
1608 let what_rustc_thinks = Item::from_hir_id_and_parts(
1610 Some(self.ident.name),
1611 StructFieldItem(self.ty.clean(cx)),
1614 // Don't show `pub` for fields on enum variants; they are always public
1615 Item { visibility: self.vis.clean(cx), ..what_rustc_thinks }
1619 impl Clean<Item> for ty::FieldDef {
1620 fn clean(&self, cx: &mut DocContext<'_>) -> Item {
1621 let what_rustc_thinks = Item::from_def_id_and_parts(
1623 Some(self.ident.name),
1624 StructFieldItem(cx.tcx.type_of(self.did).clean(cx)),
1627 // Don't show `pub` for fields on enum variants; they are always public
1628 Item { visibility: self.vis.clean(cx), ..what_rustc_thinks }
1632 impl Clean<Visibility> for hir::Visibility<'_> {
1633 fn clean(&self, cx: &mut DocContext<'_>) -> Visibility {
1635 hir::VisibilityKind::Public => Visibility::Public,
1636 hir::VisibilityKind::Inherited => Visibility::Inherited,
1637 hir::VisibilityKind::Crate(_) => {
1638 let krate = DefId::local(CRATE_DEF_INDEX);
1639 Visibility::Restricted(krate)
1641 hir::VisibilityKind::Restricted { ref path, .. } => {
1642 let path = path.clean(cx);
1643 let did = register_res(cx, path.res);
1644 Visibility::Restricted(did)
1650 impl Clean<Visibility> for ty::Visibility {
1651 fn clean(&self, _cx: &mut DocContext<'_>) -> Visibility {
1653 ty::Visibility::Public => Visibility::Public,
1654 // NOTE: this is not quite right: `ty` uses `Invisible` to mean 'private',
1655 // while rustdoc really does mean inherited. That means that for enum variants, such as
1656 // `pub enum E { V }`, `V` will be marked as `Public` by `ty`, but as `Inherited` by rustdoc.
1657 // This is the main reason `impl Clean for hir::Visibility` still exists; various parts of clean
1658 // override `tcx.visibility` explicitly to make sure this distinction is captured.
1659 ty::Visibility::Invisible => Visibility::Inherited,
1660 ty::Visibility::Restricted(module) => Visibility::Restricted(module),
1665 impl Clean<VariantStruct> for rustc_hir::VariantData<'_> {
1666 fn clean(&self, cx: &mut DocContext<'_>) -> VariantStruct {
1668 struct_type: CtorKind::from_hir(self),
1669 fields: self.fields().iter().map(|x| x.clean(cx)).collect(),
1670 fields_stripped: false,
1675 impl Clean<Vec<Item>> for hir::VariantData<'_> {
1676 fn clean(&self, cx: &mut DocContext<'_>) -> Vec<Item> {
1677 self.fields().iter().map(|x| x.clean(cx)).collect()
1681 impl Clean<Item> for ty::VariantDef {
1682 fn clean(&self, cx: &mut DocContext<'_>) -> Item {
1683 let kind = match self.ctor_kind {
1684 CtorKind::Const => Variant::CLike,
1685 CtorKind::Fn => Variant::Tuple(
1689 let name = Some(field.ident.name);
1690 let kind = StructFieldItem(cx.tcx.type_of(field.did).clean(cx));
1691 let what_rustc_thinks =
1692 Item::from_def_id_and_parts(field.did, name, kind, cx);
1693 // don't show `pub` for fields, which are always public
1694 Item { visibility: Visibility::Inherited, ..what_rustc_thinks }
1698 CtorKind::Fictive => Variant::Struct(VariantStruct {
1699 struct_type: CtorKind::Fictive,
1700 fields_stripped: false,
1705 let name = Some(field.ident.name);
1706 let kind = StructFieldItem(cx.tcx.type_of(field.did).clean(cx));
1707 let what_rustc_thinks =
1708 Item::from_def_id_and_parts(field.did, name, kind, cx);
1709 // don't show `pub` for fields, which are always public
1710 Item { visibility: Visibility::Inherited, ..what_rustc_thinks }
1715 let what_rustc_thinks =
1716 Item::from_def_id_and_parts(self.def_id, Some(self.ident.name), VariantItem(kind), cx);
1717 // don't show `pub` for fields, which are always public
1718 Item { visibility: Inherited, ..what_rustc_thinks }
1722 impl Clean<Variant> for hir::VariantData<'_> {
1723 fn clean(&self, cx: &mut DocContext<'_>) -> Variant {
1725 hir::VariantData::Struct(..) => Variant::Struct(self.clean(cx)),
1726 hir::VariantData::Tuple(..) => Variant::Tuple(self.clean(cx)),
1727 hir::VariantData::Unit(..) => Variant::CLike,
1732 impl Clean<Path> for hir::Path<'_> {
1733 fn clean(&self, cx: &mut DocContext<'_>) -> Path {
1735 global: self.is_global(),
1737 segments: if self.is_global() { &self.segments[1..] } else { &self.segments }.clean(cx),
1742 impl Clean<GenericArgs> for hir::GenericArgs<'_> {
1743 fn clean(&self, cx: &mut DocContext<'_>) -> GenericArgs {
1744 if self.parenthesized {
1745 let output = self.bindings[0].ty().clean(cx);
1747 if output != Type::Tuple(Vec::new()) { Some(Box::new(output)) } else { None };
1748 GenericArgs::Parenthesized { inputs: self.inputs().clean(cx), output }
1750 GenericArgs::AngleBracketed {
1754 .map(|arg| match arg {
1755 hir::GenericArg::Lifetime(lt) if !lt.is_elided() => {
1756 GenericArg::Lifetime(lt.clean(cx))
1758 hir::GenericArg::Lifetime(_) => GenericArg::Lifetime(Lifetime::elided()),
1759 hir::GenericArg::Type(ty) => GenericArg::Type(ty.clean(cx)),
1760 hir::GenericArg::Const(ct) => GenericArg::Const(Box::new(ct.clean(cx))),
1761 hir::GenericArg::Infer(_inf) => GenericArg::Infer,
1764 bindings: self.bindings.clean(cx),
1770 impl Clean<PathSegment> for hir::PathSegment<'_> {
1771 fn clean(&self, cx: &mut DocContext<'_>) -> PathSegment {
1772 PathSegment { name: self.ident.name, args: self.args().clean(cx) }
1776 impl Clean<BareFunctionDecl> for hir::BareFnTy<'_> {
1777 fn clean(&self, cx: &mut DocContext<'_>) -> BareFunctionDecl {
1778 let (generic_params, decl) = enter_impl_trait(cx, |cx| {
1779 (self.generic_params.clean(cx), (&*self.decl, self.param_names).clean(cx))
1781 BareFunctionDecl { unsafety: self.unsafety, abi: self.abi, decl, generic_params }
1785 impl Clean<Vec<Item>> for (&hir::Item<'_>, Option<Symbol>) {
1786 fn clean(&self, cx: &mut DocContext<'_>) -> Vec<Item> {
1789 let (item, renamed) = self;
1790 let def_id = item.def_id.to_def_id();
1791 let mut name = renamed.unwrap_or_else(|| cx.tcx.hir().name(item.hir_id()));
1792 cx.with_param_env(def_id, |cx| {
1793 let kind = match item.kind {
1794 ItemKind::Static(ty, mutability, body_id) => {
1795 StaticItem(Static { type_: ty.clean(cx), mutability, expr: Some(body_id) })
1797 ItemKind::Const(ty, body_id) => ConstantItem(Constant {
1798 type_: ty.clean(cx),
1799 kind: ConstantKind::Local { body: body_id, def_id },
1801 ItemKind::OpaqueTy(ref ty) => OpaqueTyItem(OpaqueTy {
1802 bounds: ty.bounds.clean(cx),
1803 generics: ty.generics.clean(cx),
1805 ItemKind::TyAlias(hir_ty, ref generics) => {
1806 let rustdoc_ty = hir_ty.clean(cx);
1807 let ty = hir_ty_to_ty(cx.tcx, hir_ty).clean(cx);
1811 generics: generics.clean(cx),
1812 item_type: Some(ty),
1817 ItemKind::Enum(ref def, ref generics) => EnumItem(Enum {
1818 variants: def.variants.iter().map(|v| v.clean(cx)).collect(),
1819 generics: generics.clean(cx),
1820 variants_stripped: false,
1822 ItemKind::TraitAlias(ref generics, bounds) => TraitAliasItem(TraitAlias {
1823 generics: generics.clean(cx),
1824 bounds: bounds.clean(cx),
1826 ItemKind::Union(ref variant_data, ref generics) => UnionItem(Union {
1827 generics: generics.clean(cx),
1828 fields: variant_data.fields().clean(cx),
1829 fields_stripped: false,
1831 ItemKind::Struct(ref variant_data, ref generics) => StructItem(Struct {
1832 struct_type: CtorKind::from_hir(variant_data),
1833 generics: generics.clean(cx),
1834 fields: variant_data.fields().clean(cx),
1835 fields_stripped: false,
1837 ItemKind::Impl(ref impl_) => return clean_impl(impl_, item.hir_id(), cx),
1838 // proc macros can have a name set by attributes
1839 ItemKind::Fn(ref sig, ref generics, body_id) => {
1840 clean_fn_or_proc_macro(item, sig, generics, body_id, &mut name, cx)
1842 ItemKind::Macro(ref macro_def) => MacroItem(Macro {
1843 source: display_macro_source(cx, name, ¯o_def, def_id, &item.vis),
1845 ItemKind::Trait(is_auto, unsafety, ref generics, ref bounds, ref item_ids) => {
1846 let items = item_ids
1848 .map(|ti| cx.tcx.hir().trait_item(ti.id).clean(cx))
1853 generics: generics.clean(cx),
1854 bounds: bounds.clean(cx),
1855 is_auto: is_auto.clean(cx),
1858 ItemKind::ExternCrate(orig_name) => {
1859 return clean_extern_crate(item, name, orig_name, cx);
1861 ItemKind::Use(path, kind) => {
1862 return clean_use_statement(item, name, path, kind, cx);
1864 _ => unreachable!("not yet converted"),
1867 vec![Item::from_def_id_and_parts(def_id, Some(name), kind, cx)]
1872 impl Clean<Item> for hir::Variant<'_> {
1873 fn clean(&self, cx: &mut DocContext<'_>) -> Item {
1874 let kind = VariantItem(self.data.clean(cx));
1875 let what_rustc_thinks =
1876 Item::from_hir_id_and_parts(self.id, Some(self.ident.name), kind, cx);
1877 // don't show `pub` for variants, which are always public
1878 Item { visibility: Inherited, ..what_rustc_thinks }
1882 impl Clean<bool> for ty::ImplPolarity {
1883 /// Returns whether the impl has negative polarity.
1884 fn clean(&self, _: &mut DocContext<'_>) -> bool {
1886 &ty::ImplPolarity::Positive |
1887 // FIXME: do we want to do something else here?
1888 &ty::ImplPolarity::Reservation => false,
1889 &ty::ImplPolarity::Negative => true,
1894 fn clean_impl(impl_: &hir::Impl<'_>, hir_id: hir::HirId, cx: &mut DocContext<'_>) -> Vec<Item> {
1896 let mut ret = Vec::new();
1897 let trait_ = impl_.of_trait.clean(cx);
1899 impl_.items.iter().map(|ii| tcx.hir().impl_item(ii.id).clean(cx)).collect::<Vec<_>>();
1900 let def_id = tcx.hir().local_def_id(hir_id);
1902 // If this impl block is an implementation of the Deref trait, then we
1903 // need to try inlining the target's inherent impl blocks as well.
1904 if trait_.def_id() == tcx.lang_items().deref_trait() {
1905 build_deref_target_impls(cx, &items, &mut ret);
1908 let for_ = impl_.self_ty.clean(cx);
1909 let type_alias = for_.def_id().and_then(|did| match tcx.def_kind(did) {
1910 DefKind::TyAlias => Some(tcx.type_of(did).clean(cx)),
1913 let mut make_item = |trait_: Option<Type>, for_: Type, items: Vec<Item>| {
1914 let kind = ImplItem(Impl {
1915 span: types::rustc_span(tcx.hir().local_def_id(hir_id).to_def_id(), tcx),
1916 unsafety: impl_.unsafety,
1917 generics: impl_.generics.clean(cx),
1921 negative_polarity: tcx.impl_polarity(def_id).clean(cx),
1925 Item::from_hir_id_and_parts(hir_id, None, kind, cx)
1927 if let Some(type_alias) = type_alias {
1928 ret.push(make_item(trait_.clone(), type_alias, items.clone()));
1930 ret.push(make_item(trait_, for_, items));
1934 fn clean_extern_crate(
1935 krate: &hir::Item<'_>,
1937 orig_name: Option<Symbol>,
1938 cx: &mut DocContext<'_>,
1940 // this is the ID of the `extern crate` statement
1941 let cnum = cx.tcx.extern_mod_stmt_cnum(krate.def_id).unwrap_or(LOCAL_CRATE);
1942 // this is the ID of the crate itself
1943 let crate_def_id = DefId { krate: cnum, index: CRATE_DEF_INDEX };
1944 let attrs = cx.tcx.hir().attrs(krate.hir_id());
1945 let please_inline = krate.vis.node.is_pub()
1946 && attrs.iter().any(|a| {
1947 a.has_name(sym::doc)
1948 && match a.meta_item_list() {
1949 Some(l) => attr::list_contains_name(&l, sym::inline),
1955 let mut visited = FxHashSet::default();
1957 let res = Res::Def(DefKind::Mod, crate_def_id);
1959 if let Some(items) = inline::try_inline(
1961 cx.tcx.parent_module(krate.hir_id()).to_def_id(),
1962 Some(krate.def_id.to_def_id()),
1972 // FIXME: using `from_def_id_and_kind` breaks `rustdoc/masked` for some reason
1975 attrs: box attrs.clean(cx),
1976 def_id: crate_def_id.into(),
1977 visibility: krate.vis.clean(cx),
1978 kind: box ExternCrateItem { src: orig_name },
1979 cfg: attrs.cfg(cx.sess()),
1983 fn clean_use_statement(
1984 import: &hir::Item<'_>,
1986 path: &hir::Path<'_>,
1988 cx: &mut DocContext<'_>,
1990 // We need this comparison because some imports (for std types for example)
1991 // are "inserted" as well but directly by the compiler and they should not be
1992 // taken into account.
1993 if import.span.ctxt().outer_expn_data().kind == ExpnKind::AstPass(AstPass::StdImports) {
1997 let attrs = cx.tcx.hir().attrs(import.hir_id());
1998 let inline_attr = attrs.lists(sym::doc).get_word_attr(sym::inline);
1999 let pub_underscore = import.vis.node.is_pub() && name == kw::Underscore;
2002 if let Some(ref inline) = inline_attr {
2003 rustc_errors::struct_span_err!(
2007 "anonymous imports cannot be inlined"
2009 .span_label(import.span, "anonymous import")
2014 // We consider inlining the documentation of `pub use` statements, but we
2015 // forcefully don't inline if this is not public or if the
2016 // #[doc(no_inline)] attribute is present.
2017 // Don't inline doc(hidden) imports so they can be stripped at a later stage.
2018 let mut denied = !(import.vis.node.is_pub()
2019 || (cx.render_options.document_private && import.vis.node.is_pub_restricted()))
2021 || attrs.iter().any(|a| {
2022 a.has_name(sym::doc)
2023 && match a.meta_item_list() {
2025 attr::list_contains_name(&l, sym::no_inline)
2026 || attr::list_contains_name(&l, sym::hidden)
2032 // Also check whether imports were asked to be inlined, in case we're trying to re-export a
2033 // crate in Rust 2018+
2034 let path = path.clean(cx);
2035 let inner = if kind == hir::UseKind::Glob {
2037 let mut visited = FxHashSet::default();
2038 if let Some(items) = inline::try_inline_glob(cx, path.res, &mut visited) {
2042 Import::new_glob(resolve_use_source(cx, path), true)
2044 if inline_attr.is_none() {
2045 if let Res::Def(DefKind::Mod, did) = path.res {
2046 if !did.is_local() && did.index == CRATE_DEF_INDEX {
2047 // if we're `pub use`ing an extern crate root, don't inline it unless we
2048 // were specifically asked for it
2054 let mut visited = FxHashSet::default();
2055 let import_def_id = import.def_id.to_def_id();
2057 if let Some(mut items) = inline::try_inline(
2059 cx.tcx.parent_module(import.hir_id()).to_def_id(),
2060 Some(import_def_id),
2066 items.push(Item::from_def_id_and_parts(
2069 ImportItem(Import::new_simple(name, resolve_use_source(cx, path), false)),
2075 Import::new_simple(name, resolve_use_source(cx, path), true)
2078 vec![Item::from_def_id_and_parts(import.def_id.to_def_id(), None, ImportItem(inner), cx)]
2081 impl Clean<Item> for (&hir::ForeignItem<'_>, Option<Symbol>) {
2082 fn clean(&self, cx: &mut DocContext<'_>) -> Item {
2083 let (item, renamed) = self;
2084 cx.with_param_env(item.def_id.to_def_id(), |cx| {
2085 let kind = match item.kind {
2086 hir::ForeignItemKind::Fn(ref decl, ref names, ref generics) => {
2087 let abi = cx.tcx.hir().get_foreign_abi(item.hir_id());
2088 let (generics, decl) = enter_impl_trait(cx, |cx| {
2089 (generics.clean(cx), (&**decl, &names[..]).clean(cx))
2091 ForeignFunctionItem(Function {
2094 header: hir::FnHeader {
2095 unsafety: if abi == Abi::RustIntrinsic {
2096 intrinsic_operation_unsafety(item.ident.name)
2098 hir::Unsafety::Unsafe
2101 constness: hir::Constness::NotConst,
2102 asyncness: hir::IsAsync::NotAsync,
2106 hir::ForeignItemKind::Static(ref ty, mutability) => {
2107 ForeignStaticItem(Static { type_: ty.clean(cx), mutability, expr: None })
2109 hir::ForeignItemKind::Type => ForeignTypeItem,
2112 Item::from_hir_id_and_parts(
2114 Some(renamed.unwrap_or(item.ident.name)),
2122 impl Clean<TypeBinding> for hir::TypeBinding<'_> {
2123 fn clean(&self, cx: &mut DocContext<'_>) -> TypeBinding {
2124 TypeBinding { name: self.ident.name, kind: self.kind.clean(cx) }
2128 impl Clean<TypeBindingKind> for hir::TypeBindingKind<'_> {
2129 fn clean(&self, cx: &mut DocContext<'_>) -> TypeBindingKind {
2131 hir::TypeBindingKind::Equality { ref ty } => {
2132 TypeBindingKind::Equality { ty: ty.clean(cx) }
2134 hir::TypeBindingKind::Constraint { ref bounds } => {
2135 TypeBindingKind::Constraint { bounds: bounds.iter().map(|b| b.clean(cx)).collect() }