src/librustdoc/clean/mod.rs

   1 //! This module contains the "cleaned" pieces of the AST, and the functions
   2 //! that clean them.
   3
   4 mod auto_trait;
   5 mod blanket_impl;
   6 pub mod cfg;
   7 pub mod inline;
   8 mod simplify;
   9 pub mod types;
  10 pub mod utils;
  11
  12 use rustc_ast::ast;
  13 use rustc_attr as attr;
  14 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
  15 use rustc_hir as hir;
  16 use rustc_hir::def::{CtorKind, DefKind, Res};
  17 use rustc_hir::def_id::{CrateNum, DefId, CRATE_DEF_INDEX};
  18 use rustc_index::vec::{Idx, IndexVec};
  19 use rustc_infer::infer::region_constraints::{Constraint, RegionConstraintData};
  20 use rustc_middle::middle::resolve_lifetime as rl;
  21 use rustc_middle::middle::stability;
  22 use rustc_middle::ty::fold::TypeFolder;
  23 use rustc_middle::ty::subst::InternalSubsts;
  24 use rustc_middle::ty::{self, AdtKind, Lift, Ty, TyCtxt};
  25 use rustc_mir::const_eval::is_min_const_fn;
  26 use rustc_span::hygiene::MacroKind;
  27 use rustc_span::symbol::{kw, sym, Ident, Symbol};
  28 use rustc_span::{self, Pos};
  29 use rustc_typeck::hir_ty_to_ty;
  30
  31 use std::collections::hash_map::Entry;
  32 use std::default::Default;
  33 use std::hash::Hash;
  34 use std::rc::Rc;
  35 use std::{mem, vec};
  36
  37 use crate::core::{self, DocContext, ImplTraitParam};
  38 use crate::doctree;
  39
  40 use utils::*;
  41
  42 pub use utils::{get_auto_trait_and_blanket_impls, krate, register_res};
  43
  44 pub use self::types::FnRetTy::*;
  45 pub use self::types::ItemEnum::*;
  46 pub use self::types::SelfTy::*;
  47 pub use self::types::Type::*;
  48 pub use self::types::Visibility::{Inherited, Public};
  49 pub use self::types::*;
  50
  51 const FN_OUTPUT_NAME: &str = "Output";
  52
  53 pub trait Clean<T> {
  54     fn clean(&self, cx: &DocContext<'_>) -> T;
  55 }
  56
  57 impl<T: Clean<U>, U> Clean<Vec<U>> for [T] {
  58     fn clean(&self, cx: &DocContext<'_>) -> Vec<U> {
  59         self.iter().map(|x| x.clean(cx)).collect()
  60     }
  61 }
  62
  63 impl<T: Clean<U>, U, V: Idx> Clean<IndexVec<V, U>> for IndexVec<V, T> {
  64     fn clean(&self, cx: &DocContext<'_>) -> IndexVec<V, U> {
  65         self.iter().map(|x| x.clean(cx)).collect()
  66     }
  67 }
  68
  69 impl<T: Clean<U>, U> Clean<U> for &T {
  70     fn clean(&self, cx: &DocContext<'_>) -> U {
  71         (**self).clean(cx)
  72     }
  73 }
  74
  75 impl<T: Clean<U>, U> Clean<U> for Rc<T> {
  76     fn clean(&self, cx: &DocContext<'_>) -> U {
  77         (**self).clean(cx)
  78     }
  79 }
  80
  81 impl<T: Clean<U>, U> Clean<Option<U>> for Option<T> {
  82     fn clean(&self, cx: &DocContext<'_>) -> Option<U> {
  83         self.as_ref().map(|v| v.clean(cx))
  84     }
  85 }
  86
  87 impl Clean<ExternalCrate> for CrateNum {
  88     fn clean(&self, cx: &DocContext<'_>) -> ExternalCrate {
  89         let root = DefId { krate: *self, index: CRATE_DEF_INDEX };
  90         let krate_span = cx.tcx.def_span(root);
  91         let krate_src = cx.sess().source_map().span_to_filename(krate_span);
  92
  93         // Collect all inner modules which are tagged as implementations of
  94         // primitives.
  95         //
  96         // Note that this loop only searches the top-level items of the crate,
  97         // and this is intentional. If we were to search the entire crate for an
  98         // item tagged with `#[doc(primitive)]` then we would also have to
  99         // search the entirety of external modules for items tagged
 100         // `#[doc(primitive)]`, which is a pretty inefficient process (decoding
 101         // all that metadata unconditionally).
 102         //
 103         // In order to keep the metadata load under control, the
 104         // `#[doc(primitive)]` feature is explicitly designed to only allow the
 105         // primitive tags to show up as the top level items in a crate.
 106         //
 107         // Also note that this does not attempt to deal with modules tagged
 108         // duplicately for the same primitive. This is handled later on when
 109         // rendering by delegating everything to a hash map.
 110         let as_primitive = |res: Res| {
 111             if let Res::Def(DefKind::Mod, def_id) = res {
 112                 let attrs = cx.tcx.get_attrs(def_id).clean(cx);
 113                 let mut prim = None;
 114                 for attr in attrs.lists(sym::doc) {
 115                     if let Some(v) = attr.value_str() {
 116                         if attr.check_name(sym::primitive) {
 117                             prim = PrimitiveType::from_str(&v.as_str());
 118                             if prim.is_some() {
 119                                 break;
 120                             }
 121                             // FIXME: should warn on unknown primitives?
 122                         }
 123                     }
 124                 }
 125                 return prim.map(|p| (def_id, p, attrs));
 126             }
 127             None
 128         };
 129         let primitives = if root.is_local() {
 130             cx.tcx
 131                 .hir()
 132                 .krate()
 133                 .item
 134                 .module
 135                 .item_ids
 136                 .iter()
 137                 .filter_map(|&id| {
 138                     let item = cx.tcx.hir().expect_item(id.id);
 139                     match item.kind {
 140                         hir::ItemKind::Mod(_) => as_primitive(Res::Def(
 141                             DefKind::Mod,
 142                             cx.tcx.hir().local_def_id(id.id).to_def_id(),
 143                         )),
 144                         hir::ItemKind::Use(ref path, hir::UseKind::Single)
 145                             if item.vis.node.is_pub() =>
 146                         {
 147                             as_primitive(path.res).map(|(_, prim, attrs)| {
 148                                 // Pretend the primitive is local.
 149                                 (cx.tcx.hir().local_def_id(id.id).to_def_id(), prim, attrs)
 150                             })
 151                         }
 152                         _ => None,
 153                     }
 154                 })
 155                 .collect()
 156         } else {
 157             cx.tcx
 158                 .item_children(root)
 159                 .iter()
 160                 .map(|item| item.res)
 161                 .filter_map(as_primitive)
 162                 .collect()
 163         };
 164
 165         let as_keyword = |res: Res| {
 166             if let Res::Def(DefKind::Mod, def_id) = res {
 167                 let attrs = cx.tcx.get_attrs(def_id).clean(cx);
 168                 let mut keyword = None;
 169                 for attr in attrs.lists(sym::doc) {
 170                     if let Some(v) = attr.value_str() {
 171                         if attr.check_name(sym::keyword) {
 172                             if v.is_doc_keyword() {
 173                                 keyword = Some(v.to_string());
 174                                 break;
 175                             }
 176                             // FIXME: should warn on unknown keywords?
 177                         }
 178                     }
 179                 }
 180                 return keyword.map(|p| (def_id, p, attrs));
 181             }
 182             None
 183         };
 184         let keywords = if root.is_local() {
 185             cx.tcx
 186                 .hir()
 187                 .krate()
 188                 .item
 189                 .module
 190                 .item_ids
 191                 .iter()
 192                 .filter_map(|&id| {
 193                     let item = cx.tcx.hir().expect_item(id.id);
 194                     match item.kind {
 195                         hir::ItemKind::Mod(_) => as_keyword(Res::Def(
 196                             DefKind::Mod,
 197                             cx.tcx.hir().local_def_id(id.id).to_def_id(),
 198                         )),
 199                         hir::ItemKind::Use(ref path, hir::UseKind::Single)
 200                             if item.vis.node.is_pub() =>
 201                         {
 202                             as_keyword(path.res).map(|(_, prim, attrs)| {
 203                                 (cx.tcx.hir().local_def_id(id.id).to_def_id(), prim, attrs)
 204                             })
 205                         }
 206                         _ => None,
 207                     }
 208                 })
 209                 .collect()
 210         } else {
 211             cx.tcx.item_children(root).iter().map(|item| item.res).filter_map(as_keyword).collect()
 212         };
 213
 214         ExternalCrate {
 215             name: cx.tcx.crate_name(*self).to_string(),
 216             src: krate_src,
 217             attrs: cx.tcx.get_attrs(root).clean(cx),
 218             primitives,
 219             keywords,
 220         }
 221     }
 222 }
 223
 224 impl Clean<Item> for doctree::Module<'_> {
 225     fn clean(&self, cx: &DocContext<'_>) -> Item {
 226         let name = if self.name.is_some() {
 227             self.name.expect("No name provided").clean(cx)
 228         } else {
 229             String::new()
 230         };
 231
 232         // maintain a stack of mod ids, for doc comment path resolution
 233         // but we also need to resolve the module's own docs based on whether its docs were written
 234         // inside or outside the module, so check for that
 235         let attrs = self.attrs.clean(cx);
 236
 237         let mut items: Vec<Item> = vec![];
 238         items.extend(self.extern_crates.iter().flat_map(|x| x.clean(cx)));
 239         items.extend(self.imports.iter().flat_map(|x| x.clean(cx)));
 240         items.extend(self.structs.iter().map(|x| x.clean(cx)));
 241         items.extend(self.unions.iter().map(|x| x.clean(cx)));
 242         items.extend(self.enums.iter().map(|x| x.clean(cx)));
 243         items.extend(self.fns.iter().map(|x| x.clean(cx)));
 244         items.extend(self.foreigns.iter().map(|x| x.clean(cx)));
 245         items.extend(self.mods.iter().map(|x| x.clean(cx)));
 246         items.extend(self.typedefs.iter().map(|x| x.clean(cx)));
 247         items.extend(self.opaque_tys.iter().map(|x| x.clean(cx)));
 248         items.extend(self.statics.iter().map(|x| x.clean(cx)));
 249         items.extend(self.constants.iter().map(|x| x.clean(cx)));
 250         items.extend(self.traits.iter().map(|x| x.clean(cx)));
 251         items.extend(self.impls.iter().flat_map(|x| x.clean(cx)));
 252         items.extend(self.macros.iter().map(|x| x.clean(cx)));
 253         items.extend(self.proc_macros.iter().map(|x| x.clean(cx)));
 254         items.extend(self.trait_aliases.iter().map(|x| x.clean(cx)));
 255
 256         // determine if we should display the inner contents or
 257         // the outer `mod` item for the source code.
 258         let whence = {
 259             let sm = cx.sess().source_map();
 260             let outer = sm.lookup_char_pos(self.where_outer.lo());
 261             let inner = sm.lookup_char_pos(self.where_inner.lo());
 262             if outer.file.start_pos == inner.file.start_pos {
 263                 // mod foo { ... }
 264                 self.where_outer
 265             } else {
 266                 // mod foo; (and a separate SourceFile for the contents)
 267                 self.where_inner
 268             }
 269         };
 270
 271         Item {
 272             name: Some(name),
 273             attrs,
 274             source: whence.clean(cx),
 275             visibility: self.vis.clean(cx),
 276             stability: cx.stability(self.id).clean(cx),
 277             deprecation: cx.deprecation(self.id).clean(cx),
 278             def_id: cx.tcx.hir().local_def_id(self.id).to_def_id(),
 279             inner: ModuleItem(Module { is_crate: self.is_crate, items }),
 280         }
 281     }
 282 }
 283
 284 impl Clean<Attributes> for [ast::Attribute] {
 285     fn clean(&self, cx: &DocContext<'_>) -> Attributes {
 286         Attributes::from_ast(cx.sess().diagnostic(), self)
 287     }
 288 }
 289
 290 impl Clean<GenericBound> for hir::GenericBound<'_> {
 291     fn clean(&self, cx: &DocContext<'_>) -> GenericBound {
 292         match *self {
 293             hir::GenericBound::Outlives(lt) => GenericBound::Outlives(lt.clean(cx)),
 294             hir::GenericBound::Trait(ref t, modifier) => {
 295                 GenericBound::TraitBound(t.clean(cx), modifier)
 296             }
 297         }
 298     }
 299 }
 300
 301 impl Clean<Type> for (ty::TraitRef<'_>, &[TypeBinding]) {
 302     fn clean(&self, cx: &DocContext<'_>) -> Type {
 303         let (trait_ref, bounds) = *self;
 304         inline::record_extern_fqn(cx, trait_ref.def_id, TypeKind::Trait);
 305         let path = external_path(
 306             cx,
 307             cx.tcx.item_name(trait_ref.def_id),
 308             Some(trait_ref.def_id),
 309             true,
 310             bounds.to_vec(),
 311             trait_ref.substs,
 312         );
 313
 314         debug!("ty::TraitRef\n  subst: {:?}\n", trait_ref.substs);
 315
 316         ResolvedPath { path, param_names: None, did: trait_ref.def_id, is_generic: false }
 317     }
 318 }
 319
 320 impl<'tcx> Clean<GenericBound> for ty::TraitRef<'tcx> {
 321     fn clean(&self, cx: &DocContext<'_>) -> GenericBound {
 322         GenericBound::TraitBound(
 323             PolyTrait { trait_: (*self, &[][..]).clean(cx), generic_params: vec![] },
 324             hir::TraitBoundModifier::None,
 325         )
 326     }
 327 }
 328
 329 impl Clean<GenericBound> for (ty::PolyTraitRef<'_>, &[TypeBinding]) {
 330     fn clean(&self, cx: &DocContext<'_>) -> GenericBound {
 331         let (poly_trait_ref, bounds) = *self;
 332         let poly_trait_ref = poly_trait_ref.lift_to_tcx(cx.tcx).unwrap();
 333
 334         // collect any late bound regions
 335         let late_bound_regions: Vec<_> = cx
 336             .tcx
 337             .collect_referenced_late_bound_regions(&poly_trait_ref)
 338             .into_iter()
 339             .filter_map(|br| match br {
 340                 ty::BrNamed(_, name) => Some(GenericParamDef {
 341                     name: name.to_string(),
 342                     kind: GenericParamDefKind::Lifetime,
 343                 }),
 344                 _ => None,
 345             })
 346             .collect();
 347
 348         GenericBound::TraitBound(
 349             PolyTrait {
 350                 trait_: (*poly_trait_ref.skip_binder(), bounds).clean(cx),
 351                 generic_params: late_bound_regions,
 352             },
 353             hir::TraitBoundModifier::None,
 354         )
 355     }
 356 }
 357
 358 impl<'tcx> Clean<GenericBound> for ty::PolyTraitRef<'tcx> {
 359     fn clean(&self, cx: &DocContext<'_>) -> GenericBound {
 360         (*self, &[][..]).clean(cx)
 361     }
 362 }
 363
 364 impl<'tcx> Clean<Option<Vec<GenericBound>>> for InternalSubsts<'tcx> {
 365     fn clean(&self, cx: &DocContext<'_>) -> Option<Vec<GenericBound>> {
 366         let mut v = Vec::new();
 367         v.extend(self.regions().filter_map(|r| r.clean(cx)).map(GenericBound::Outlives));
 368         v.extend(self.types().map(|t| {
 369             GenericBound::TraitBound(
 370                 PolyTrait { trait_: t.clean(cx), generic_params: Vec::new() },
 371                 hir::TraitBoundModifier::None,
 372             )
 373         }));
 374         if !v.is_empty() { Some(v) } else { None }
 375     }
 376 }
 377
 378 impl Clean<Lifetime> for hir::Lifetime {
 379     fn clean(&self, cx: &DocContext<'_>) -> Lifetime {
 380         let def = cx.tcx.named_region(self.hir_id);
 381         match def {
 382             Some(
 383                 rl::Region::EarlyBound(_, node_id, _)
 384                 | rl::Region::LateBound(_, node_id, _)
 385                 | rl::Region::Free(_, node_id),
 386             ) => {
 387                 if let Some(lt) = cx.lt_substs.borrow().get(&node_id).cloned() {
 388                     return lt;
 389                 }
 390             }
 391             _ => {}
 392         }
 393         Lifetime(self.name.ident().to_string())
 394     }
 395 }
 396
 397 impl Clean<Lifetime> for hir::GenericParam<'_> {
 398     fn clean(&self, _: &DocContext<'_>) -> Lifetime {
 399         match self.kind {
 400             hir::GenericParamKind::Lifetime { .. } => {
 401                 if !self.bounds.is_empty() {
 402                     let mut bounds = self.bounds.iter().map(|bound| match bound {
 403                         hir::GenericBound::Outlives(lt) => lt,
 404                         _ => panic!(),
 405                     });
 406                     let name = bounds.next().expect("no more bounds").name.ident();
 407                     let mut s = format!("{}: {}", self.name.ident(), name);
 408                     for bound in bounds {
 409                         s.push_str(&format!(" + {}", bound.name.ident()));
 410                     }
 411                     Lifetime(s)
 412                 } else {
 413                     Lifetime(self.name.ident().to_string())
 414                 }
 415             }
 416             _ => panic!(),
 417         }
 418     }
 419 }
 420
 421 impl Clean<Constant> for hir::ConstArg {
 422     fn clean(&self, cx: &DocContext<'_>) -> Constant {
 423         Constant {
 424             type_: cx
 425                 .tcx
 426                 .type_of(cx.tcx.hir().body_owner_def_id(self.value.body).to_def_id())
 427                 .clean(cx),
 428             expr: print_const_expr(cx, self.value.body),
 429             value: None,
 430             is_literal: is_literal_expr(cx, self.value.body.hir_id),
 431         }
 432     }
 433 }
 434
 435 impl Clean<Lifetime> for ty::GenericParamDef {
 436     fn clean(&self, _cx: &DocContext<'_>) -> Lifetime {
 437         Lifetime(self.name.to_string())
 438     }
 439 }
 440
 441 impl Clean<Option<Lifetime>> for ty::RegionKind {
 442     fn clean(&self, cx: &DocContext<'_>) -> Option<Lifetime> {
 443         match *self {
 444             ty::ReStatic => Some(Lifetime::statik()),
 445             ty::ReLateBound(_, ty::BrNamed(_, name)) => Some(Lifetime(name.to_string())),
 446             ty::ReEarlyBound(ref data) => Some(Lifetime(data.name.clean(cx))),
 447
 448             ty::ReLateBound(..)
 449             | ty::ReFree(..)
 450             | ty::ReScope(..)
 451             | ty::ReVar(..)
 452             | ty::RePlaceholder(..)
 453             | ty::ReEmpty(_)
 454             | ty::ReErased => {
 455                 debug!("cannot clean region {:?}", self);
 456                 None
 457             }
 458         }
 459     }
 460 }
 461
 462 impl Clean<WherePredicate> for hir::WherePredicate<'_> {
 463     fn clean(&self, cx: &DocContext<'_>) -> WherePredicate {
 464         match *self {
 465             hir::WherePredicate::BoundPredicate(ref wbp) => WherePredicate::BoundPredicate {
 466                 ty: wbp.bounded_ty.clean(cx),
 467                 bounds: wbp.bounds.clean(cx),
 468             },
 469
 470             hir::WherePredicate::RegionPredicate(ref wrp) => WherePredicate::RegionPredicate {
 471                 lifetime: wrp.lifetime.clean(cx),
 472                 bounds: wrp.bounds.clean(cx),
 473             },
 474
 475             hir::WherePredicate::EqPredicate(ref wrp) => {
 476                 WherePredicate::EqPredicate { lhs: wrp.lhs_ty.clean(cx), rhs: wrp.rhs_ty.clean(cx) }
 477             }
 478         }
 479     }
 480 }
 481
 482 impl<'a> Clean<Option<WherePredicate>> for ty::Predicate<'a> {
 483     fn clean(&self, cx: &DocContext<'_>) -> Option<WherePredicate> {
 484         match *self {
 485             ty::PredicateKind::Trait(ref pred, _) => Some(pred.clean(cx)),
 486             ty::PredicateKind::Subtype(ref pred) => Some(pred.clean(cx)),
 487             ty::PredicateKind::RegionOutlives(ref pred) => pred.clean(cx),
 488             ty::PredicateKind::TypeOutlives(ref pred) => pred.clean(cx),
 489             ty::PredicateKind::Projection(ref pred) => Some(pred.clean(cx)),
 490
 491             ty::PredicateKind::WellFormed(..)
 492             | ty::PredicateKind::ObjectSafe(..)
 493             | ty::PredicateKind::ClosureKind(..)
 494             | ty::PredicateKind::ConstEvaluatable(..)
 495             | ty::PredicateKind::ConstEquate(..) => panic!("not user writable"),
 496         }
 497     }
 498 }
 499
 500 impl<'a> Clean<WherePredicate> for ty::PolyTraitPredicate<'a> {
 501     fn clean(&self, cx: &DocContext<'_>) -> WherePredicate {
 502         let poly_trait_ref = self.map_bound(|pred| pred.trait_ref);
 503         WherePredicate::BoundPredicate {
 504             ty: poly_trait_ref.self_ty().clean(cx),
 505             bounds: vec![poly_trait_ref.clean(cx)],
 506         }
 507     }
 508 }
 509
 510 impl<'tcx> Clean<WherePredicate> for ty::PolySubtypePredicate<'tcx> {
 511     fn clean(&self, _cx: &DocContext<'_>) -> WherePredicate {
 512         panic!(
 513             "subtype predicates are an internal rustc artifact \
 514                 and should not be seen by rustdoc"
 515         )
 516     }
 517 }
 518
 519 impl<'tcx> Clean<Option<WherePredicate>>
 520     for ty::PolyOutlivesPredicate<ty::Region<'tcx>, ty::Region<'tcx>>
 521 {
 522     fn clean(&self, cx: &DocContext<'_>) -> Option<WherePredicate> {
 523         let ty::OutlivesPredicate(a, b) = self.skip_binder();
 524
 525         if let (ty::ReEmpty(_), ty::ReEmpty(_)) = (a, b) {
 526             return None;
 527         }
 528
 529         Some(WherePredicate::RegionPredicate {
 530             lifetime: a.clean(cx).expect("failed to clean lifetime"),
 531             bounds: vec![GenericBound::Outlives(b.clean(cx).expect("failed to clean bounds"))],
 532         })
 533     }
 534 }
 535
 536 impl<'tcx> Clean<Option<WherePredicate>> for ty::PolyOutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>> {
 537     fn clean(&self, cx: &DocContext<'_>) -> Option<WherePredicate> {
 538         let ty::OutlivesPredicate(ty, lt) = self.skip_binder();
 539
 540         if let ty::ReEmpty(_) = lt {
 541             return None;
 542         }
 543
 544         Some(WherePredicate::BoundPredicate {
 545             ty: ty.clean(cx),
 546             bounds: vec![GenericBound::Outlives(lt.clean(cx).expect("failed to clean lifetimes"))],
 547         })
 548     }
 549 }
 550
 551 impl<'tcx> Clean<WherePredicate> for ty::PolyProjectionPredicate<'tcx> {
 552     fn clean(&self, cx: &DocContext<'_>) -> WherePredicate {
 553         let ty::ProjectionPredicate { projection_ty, ty } = *self.skip_binder();
 554         WherePredicate::EqPredicate { lhs: projection_ty.clean(cx), rhs: ty.clean(cx) }
 555     }
 556 }
 557
 558 impl<'tcx> Clean<Type> for ty::ProjectionTy<'tcx> {
 559     fn clean(&self, cx: &DocContext<'_>) -> Type {
 560         let lifted = self.lift_to_tcx(cx.tcx).unwrap();
 561         let trait_ = match lifted.trait_ref(cx.tcx).clean(cx) {
 562             GenericBound::TraitBound(t, _) => t.trait_,
 563             GenericBound::Outlives(_) => panic!("cleaning a trait got a lifetime"),
 564         };
 565         Type::QPath {
 566             name: cx.tcx.associated_item(self.item_def_id).ident.name.clean(cx),
 567             self_type: box self.self_ty().clean(cx),
 568             trait_: box trait_,
 569         }
 570     }
 571 }
 572
 573 impl Clean<GenericParamDef> for ty::GenericParamDef {
 574     fn clean(&self, cx: &DocContext<'_>) -> GenericParamDef {
 575         let (name, kind) = match self.kind {
 576             ty::GenericParamDefKind::Lifetime => {
 577                 (self.name.to_string(), GenericParamDefKind::Lifetime)
 578             }
 579             ty::GenericParamDefKind::Type { has_default, synthetic, .. } => {
 580                 let default =
 581                     if has_default { Some(cx.tcx.type_of(self.def_id).clean(cx)) } else { None };
 582                 (
 583                     self.name.clean(cx),
 584                     GenericParamDefKind::Type {
 585                         did: self.def_id,
 586                         bounds: vec![], // These are filled in from the where-clauses.
 587                         default,
 588                         synthetic,
 589                     },
 590                 )
 591             }
 592             ty::GenericParamDefKind::Const { .. } => (
 593                 self.name.clean(cx),
 594                 GenericParamDefKind::Const {
 595                     did: self.def_id,
 596                     ty: cx.tcx.type_of(self.def_id).clean(cx),
 597                 },
 598             ),
 599         };
 600
 601         GenericParamDef { name, kind }
 602     }
 603 }
 604
 605 impl Clean<GenericParamDef> for hir::GenericParam<'_> {
 606     fn clean(&self, cx: &DocContext<'_>) -> GenericParamDef {
 607         let (name, kind) = match self.kind {
 608             hir::GenericParamKind::Lifetime { .. } => {
 609                 let name = if !self.bounds.is_empty() {
 610                     let mut bounds = self.bounds.iter().map(|bound| match bound {
 611                         hir::GenericBound::Outlives(lt) => lt,
 612                         _ => panic!(),
 613                     });
 614                     let name = bounds.next().expect("no more bounds").name.ident();
 615                     let mut s = format!("{}: {}", self.name.ident(), name);
 616                     for bound in bounds {
 617                         s.push_str(&format!(" + {}", bound.name.ident()));
 618                     }
 619                     s
 620                 } else {
 621                     self.name.ident().to_string()
 622                 };
 623                 (name, GenericParamDefKind::Lifetime)
 624             }
 625             hir::GenericParamKind::Type { ref default, synthetic } => (
 626                 self.name.ident().name.clean(cx),
 627                 GenericParamDefKind::Type {
 628                     did: cx.tcx.hir().local_def_id(self.hir_id).to_def_id(),
 629                     bounds: self.bounds.clean(cx),
 630                     default: default.clean(cx),
 631                     synthetic,
 632                 },
 633             ),
 634             hir::GenericParamKind::Const { ref ty } => (
 635                 self.name.ident().name.clean(cx),
 636                 GenericParamDefKind::Const {
 637                     did: cx.tcx.hir().local_def_id(self.hir_id).to_def_id(),
 638                     ty: ty.clean(cx),
 639                 },
 640             ),
 641         };
 642
 643         GenericParamDef { name, kind }
 644     }
 645 }
 646
 647 impl Clean<Generics> for hir::Generics<'_> {
 648     fn clean(&self, cx: &DocContext<'_>) -> Generics {
 649         // Synthetic type-parameters are inserted after normal ones.
 650         // In order for normal parameters to be able to refer to synthetic ones,
 651         // scans them first.
 652         fn is_impl_trait(param: &hir::GenericParam<'_>) -> bool {
 653             match param.kind {
 654                 hir::GenericParamKind::Type { synthetic, .. } => {
 655                     synthetic == Some(hir::SyntheticTyParamKind::ImplTrait)
 656                 }
 657                 _ => false,
 658             }
 659         }
 660         let impl_trait_params = self
 661             .params
 662             .iter()
 663             .filter(|param| is_impl_trait(param))
 664             .map(|param| {
 665                 let param: GenericParamDef = param.clean(cx);
 666                 match param.kind {
 667                     GenericParamDefKind::Lifetime => unreachable!(),
 668                     GenericParamDefKind::Type { did, ref bounds, .. } => {
 669                         cx.impl_trait_bounds.borrow_mut().insert(did.into(), bounds.clone());
 670                     }
 671                     GenericParamDefKind::Const { .. } => unreachable!(),
 672                 }
 673                 param
 674             })
 675             .collect::<Vec<_>>();
 676
 677         let mut params = Vec::with_capacity(self.params.len());
 678         for p in self.params.iter().filter(|p| !is_impl_trait(p)) {
 679             let p = p.clean(cx);
 680             params.push(p);
 681         }
 682         params.extend(impl_trait_params);
 683
 684         let mut generics =
 685             Generics { params, where_predicates: self.where_clause.predicates.clean(cx) };
 686
 687         // Some duplicates are generated for ?Sized bounds between type params and where
 688         // predicates. The point in here is to move the bounds definitions from type params
 689         // to where predicates when such cases occur.
 690         for where_pred in &mut generics.where_predicates {
 691             match *where_pred {
 692                 WherePredicate::BoundPredicate { ty: Generic(ref name), ref mut bounds } => {
 693                     if bounds.is_empty() {
 694                         for param in &mut generics.params {
 695                             match param.kind {
 696                                 GenericParamDefKind::Lifetime => {}
 697                                 GenericParamDefKind::Type { bounds: ref mut ty_bounds, .. } => {
 698                                     if &param.name == name {
 699                                         mem::swap(bounds, ty_bounds);
 700                                         break;
 701                                     }
 702                                 }
 703                                 GenericParamDefKind::Const { .. } => {}
 704                             }
 705                         }
 706                     }
 707                 }
 708                 _ => continue,
 709             }
 710         }
 711         generics
 712     }
 713 }
 714
 715 impl<'a, 'tcx> Clean<Generics> for (&'a ty::Generics, ty::GenericPredicates<'tcx>) {
 716     fn clean(&self, cx: &DocContext<'_>) -> Generics {
 717         use self::WherePredicate as WP;
 718         use std::collections::BTreeMap;
 719
 720         let (gens, preds) = *self;
 721
 722         // Don't populate `cx.impl_trait_bounds` before `clean`ning `where` clauses,
 723         // since `Clean for ty::Predicate` would consume them.
 724         let mut impl_trait = BTreeMap::<ImplTraitParam, Vec<GenericBound>>::default();
 725
 726         // Bounds in the type_params and lifetimes fields are repeated in the
 727         // predicates field (see rustc_typeck::collect::ty_generics), so remove
 728         // them.
 729         let stripped_typarams = gens
 730             .params
 731             .iter()
 732             .filter_map(|param| match param.kind {
 733                 ty::GenericParamDefKind::Lifetime => None,
 734                 ty::GenericParamDefKind::Type { synthetic, .. } => {
 735                     if param.name == kw::SelfUpper {
 736                         assert_eq!(param.index, 0);
 737                         return None;
 738                     }
 739                     if synthetic == Some(hir::SyntheticTyParamKind::ImplTrait) {
 740                         impl_trait.insert(param.index.into(), vec![]);
 741                         return None;
 742                     }
 743                     Some(param.clean(cx))
 744                 }
 745                 ty::GenericParamDefKind::Const { .. } => None,
 746             })
 747             .collect::<Vec<GenericParamDef>>();
 748
 749         // param index -> [(DefId of trait, associated type name, type)]
 750         let mut impl_trait_proj = FxHashMap::<u32, Vec<(DefId, String, Ty<'tcx>)>>::default();
 751
 752         let where_predicates = preds
 753             .predicates
 754             .iter()
 755             .flat_map(|(p, _)| {
 756                 let mut projection = None;
 757                 let param_idx = (|| {
 758                     if let Some(trait_ref) = p.to_opt_poly_trait_ref() {
 759                         if let ty::Param(param) = trait_ref.self_ty().kind {
 760                             return Some(param.index);
 761                         }
 762                     } else if let Some(outlives) = p.to_opt_type_outlives() {
 763                         if let ty::Param(param) = outlives.skip_binder().0.kind {
 764                             return Some(param.index);
 765                         }
 766                     } else if let ty::PredicateKind::Projection(p) = p {
 767                         if let ty::Param(param) = p.skip_binder().projection_ty.self_ty().kind {
 768                             projection = Some(p);
 769                             return Some(param.index);
 770                         }
 771                     }
 772
 773                     None
 774                 })();
 775
 776                 if let Some(param_idx) = param_idx {
 777                     if let Some(b) = impl_trait.get_mut(&param_idx.into()) {
 778                         let p = p.clean(cx)?;
 779
 780                         b.extend(
 781                             p.get_bounds()
 782                                 .into_iter()
 783                                 .flatten()
 784                                 .cloned()
 785                                 .filter(|b| !b.is_sized_bound(cx)),
 786                         );
 787
 788                         let proj = projection
 789                             .map(|p| (p.skip_binder().projection_ty.clean(cx), p.skip_binder().ty));
 790                         if let Some(((_, trait_did, name), rhs)) =
 791                             proj.as_ref().and_then(|(lhs, rhs)| Some((lhs.projection()?, rhs)))
 792                         {
 793                             impl_trait_proj.entry(param_idx).or_default().push((
 794                                 trait_did,
 795                                 name.to_string(),
 796                                 rhs,
 797                             ));
 798                         }
 799
 800                         return None;
 801                     }
 802                 }
 803
 804                 Some(p)
 805             })
 806             .collect::<Vec<_>>();
 807
 808         for (param, mut bounds) in impl_trait {
 809             // Move trait bounds to the front.
 810             bounds.sort_by_key(|b| if let GenericBound::TraitBound(..) = b { false } else { true });
 811
 812             if let crate::core::ImplTraitParam::ParamIndex(idx) = param {
 813                 if let Some(proj) = impl_trait_proj.remove(&idx) {
 814                     for (trait_did, name, rhs) in proj {
 815                         simplify::merge_bounds(cx, &mut bounds, trait_did, &name, &rhs.clean(cx));
 816                     }
 817                 }
 818             } else {
 819                 unreachable!();
 820             }
 821
 822             cx.impl_trait_bounds.borrow_mut().insert(param, bounds);
 823         }
 824
 825         // Now that `cx.impl_trait_bounds` is populated, we can process
 826         // remaining predicates which could contain `impl Trait`.
 827         let mut where_predicates =
 828             where_predicates.into_iter().flat_map(|p| p.clean(cx)).collect::<Vec<_>>();
 829
 830         // Type parameters and have a Sized bound by default unless removed with
 831         // ?Sized. Scan through the predicates and mark any type parameter with
 832         // a Sized bound, removing the bounds as we find them.
 833         //
 834         // Note that associated types also have a sized bound by default, but we
 835         // don't actually know the set of associated types right here so that's
 836         // handled in cleaning associated types
 837         let mut sized_params = FxHashSet::default();
 838         where_predicates.retain(|pred| match *pred {
 839             WP::BoundPredicate { ty: Generic(ref g), ref bounds } => {
 840                 if bounds.iter().any(|b| b.is_sized_bound(cx)) {
 841                     sized_params.insert(g.clone());
 842                     false
 843                 } else {
 844                     true
 845                 }
 846             }
 847             _ => true,
 848         });
 849
 850         // Run through the type parameters again and insert a ?Sized
 851         // unbound for any we didn't find to be Sized.
 852         for tp in &stripped_typarams {
 853             if !sized_params.contains(&tp.name) {
 854                 where_predicates.push(WP::BoundPredicate {
 855                     ty: Type::Generic(tp.name.clone()),
 856                     bounds: vec![GenericBound::maybe_sized(cx)],
 857                 })
 858             }
 859         }
 860
 861         // It would be nice to collect all of the bounds on a type and recombine
 862         // them if possible, to avoid e.g., `where T: Foo, T: Bar, T: Sized, T: 'a`
 863         // and instead see `where T: Foo + Bar + Sized + 'a`
 864
 865         Generics {
 866             params: gens
 867                 .params
 868                 .iter()
 869                 .flat_map(|param| match param.kind {
 870                     ty::GenericParamDefKind::Lifetime => Some(param.clean(cx)),
 871                     ty::GenericParamDefKind::Type { .. } => None,
 872                     ty::GenericParamDefKind::Const { .. } => Some(param.clean(cx)),
 873                 })
 874                 .chain(simplify::ty_params(stripped_typarams).into_iter())
 875                 .collect(),
 876             where_predicates: simplify::where_clauses(cx, where_predicates),
 877         }
 878     }
 879 }
 880
 881 impl<'a> Clean<Method>
 882     for (&'a hir::FnSig<'a>, &'a hir::Generics<'a>, hir::BodyId, Option<hir::Defaultness>)
 883 {
 884     fn clean(&self, cx: &DocContext<'_>) -> Method {
 885         let (generics, decl) =
 886             enter_impl_trait(cx, || (self.1.clean(cx), (&*self.0.decl, self.2).clean(cx)));
 887         let (all_types, ret_types) = get_all_types(&generics, &decl, cx);
 888         Method { decl, generics, header: self.0.header, defaultness: self.3, all_types, ret_types }
 889     }
 890 }
 891
 892 impl Clean<Item> for doctree::Function<'_> {
 893     fn clean(&self, cx: &DocContext<'_>) -> Item {
 894         let (generics, decl) =
 895             enter_impl_trait(cx, || (self.generics.clean(cx), (self.decl, self.body).clean(cx)));
 896
 897         let did = cx.tcx.hir().local_def_id(self.id);
 898         let constness = if is_min_const_fn(cx.tcx, did.to_def_id()) {
 899             hir::Constness::Const
 900         } else {
 901             hir::Constness::NotConst
 902         };
 903         let (all_types, ret_types) = get_all_types(&generics, &decl, cx);
 904         Item {
 905             name: Some(self.name.clean(cx)),
 906             attrs: self.attrs.clean(cx),
 907             source: self.whence.clean(cx),
 908             visibility: self.vis.clean(cx),
 909             stability: cx.stability(self.id).clean(cx),
 910             deprecation: cx.deprecation(self.id).clean(cx),
 911             def_id: did.to_def_id(),
 912             inner: FunctionItem(Function {
 913                 decl,
 914                 generics,
 915                 header: hir::FnHeader { constness, ..self.header },
 916                 all_types,
 917                 ret_types,
 918             }),
 919         }
 920     }
 921 }
 922
 923 impl<'a> Clean<Arguments> for (&'a [hir::Ty<'a>], &'a [Ident]) {
 924     fn clean(&self, cx: &DocContext<'_>) -> Arguments {
 925         Arguments {
 926             values: self
 927                 .0
 928                 .iter()
 929                 .enumerate()
 930                 .map(|(i, ty)| {
 931                     let mut name =
 932                         self.1.get(i).map(|ident| ident.to_string()).unwrap_or(String::new());
 933                     if name.is_empty() {
 934                         name = "_".to_string();
 935                     }
 936                     Argument { name, type_: ty.clean(cx) }
 937                 })
 938                 .collect(),
 939         }
 940     }
 941 }
 942
 943 impl<'a> Clean<Arguments> for (&'a [hir::Ty<'a>], hir::BodyId) {
 944     fn clean(&self, cx: &DocContext<'_>) -> Arguments {
 945         let body = cx.tcx.hir().body(self.1);
 946
 947         Arguments {
 948             values: self
 949                 .0
 950                 .iter()
 951                 .enumerate()
 952                 .map(|(i, ty)| Argument {
 953                     name: name_from_pat(&body.params[i].pat),
 954                     type_: ty.clean(cx),
 955                 })
 956                 .collect(),
 957         }
 958     }
 959 }
 960
 961 impl<'a, A: Copy> Clean<FnDecl> for (&'a hir::FnDecl<'a>, A)
 962 where
 963     (&'a [hir::Ty<'a>], A): Clean<Arguments>,
 964 {
 965     fn clean(&self, cx: &DocContext<'_>) -> FnDecl {
 966         FnDecl {
 967             inputs: (&self.0.inputs[..], self.1).clean(cx),
 968             output: self.0.output.clean(cx),
 969             c_variadic: self.0.c_variadic,
 970             attrs: Attributes::default(),
 971         }
 972     }
 973 }
 974
 975 impl<'tcx> Clean<FnDecl> for (DefId, ty::PolyFnSig<'tcx>) {
 976     fn clean(&self, cx: &DocContext<'_>) -> FnDecl {
 977         let (did, sig) = *self;
 978         let mut names = if did.is_local() { &[] } else { cx.tcx.fn_arg_names(did) }.iter();
 979
 980         FnDecl {
 981             output: Return(sig.skip_binder().output().clean(cx)),
 982             attrs: Attributes::default(),
 983             c_variadic: sig.skip_binder().c_variadic,
 984             inputs: Arguments {
 985                 values: sig
 986                     .skip_binder()
 987                     .inputs()
 988                     .iter()
 989                     .map(|t| Argument {
 990                         type_: t.clean(cx),
 991                         name: names.next().map_or(String::new(), |name| name.to_string()),
 992                     })
 993                     .collect(),
 994             },
 995         }
 996     }
 997 }
 998
 999 impl Clean<FnRetTy> for hir::FnRetTy<'_> {
1000     fn clean(&self, cx: &DocContext<'_>) -> FnRetTy {
1001         match *self {
1002             Self::Return(ref typ) => Return(typ.clean(cx)),
1003             Self::DefaultReturn(..) => DefaultReturn,
1004         }
1005     }
1006 }
1007
1008 impl Clean<Item> for doctree::Trait<'_> {
1009     fn clean(&self, cx: &DocContext<'_>) -> Item {
1010         let attrs = self.attrs.clean(cx);
1011         Item {
1012             name: Some(self.name.clean(cx)),
1013             attrs,
1014             source: self.whence.clean(cx),
1015             def_id: cx.tcx.hir().local_def_id(self.id).to_def_id(),
1016             visibility: self.vis.clean(cx),
1017             stability: cx.stability(self.id).clean(cx),
1018             deprecation: cx.deprecation(self.id).clean(cx),
1019             inner: TraitItem(Trait {
1020                 auto: self.is_auto.clean(cx),
1021                 unsafety: self.unsafety,
1022                 items: self.items.iter().map(|ti| ti.clean(cx)).collect(),
1023                 generics: self.generics.clean(cx),
1024                 bounds: self.bounds.clean(cx),
1025                 is_auto: self.is_auto.clean(cx),
1026             }),
1027         }
1028     }
1029 }
1030
1031 impl Clean<Item> for doctree::TraitAlias<'_> {
1032     fn clean(&self, cx: &DocContext<'_>) -> Item {
1033         let attrs = self.attrs.clean(cx);
1034         Item {
1035             name: Some(self.name.clean(cx)),
1036             attrs,
1037             source: self.whence.clean(cx),
1038             def_id: cx.tcx.hir().local_def_id(self.id).to_def_id(),
1039             visibility: self.vis.clean(cx),
1040             stability: cx.stability(self.id).clean(cx),
1041             deprecation: cx.deprecation(self.id).clean(cx),
1042             inner: TraitAliasItem(TraitAlias {
1043                 generics: self.generics.clean(cx),
1044                 bounds: self.bounds.clean(cx),
1045             }),
1046         }
1047     }
1048 }
1049
1050 impl Clean<bool> for hir::IsAuto {
1051     fn clean(&self, _: &DocContext<'_>) -> bool {
1052         match *self {
1053             hir::IsAuto::Yes => true,
1054             hir::IsAuto::No => false,
1055         }
1056     }
1057 }
1058
1059 impl Clean<Type> for hir::TraitRef<'_> {
1060     fn clean(&self, cx: &DocContext<'_>) -> Type {
1061         resolve_type(cx, self.path.clean(cx), self.hir_ref_id)
1062     }
1063 }
1064
1065 impl Clean<PolyTrait> for hir::PolyTraitRef<'_> {
1066     fn clean(&self, cx: &DocContext<'_>) -> PolyTrait {
1067         PolyTrait {
1068             trait_: self.trait_ref.clean(cx),
1069             generic_params: self.bound_generic_params.clean(cx),
1070         }
1071     }
1072 }
1073
1074 impl Clean<TypeKind> for hir::def::DefKind {
1075     fn clean(&self, _: &DocContext<'_>) -> TypeKind {
1076         match *self {
1077             hir::def::DefKind::Mod => TypeKind::Module,
1078             hir::def::DefKind::Struct => TypeKind::Struct,
1079             hir::def::DefKind::Union => TypeKind::Union,
1080             hir::def::DefKind::Enum => TypeKind::Enum,
1081             hir::def::DefKind::Trait => TypeKind::Trait,
1082             hir::def::DefKind::TyAlias => TypeKind::Typedef,
1083             hir::def::DefKind::ForeignTy => TypeKind::Foreign,
1084             hir::def::DefKind::TraitAlias => TypeKind::TraitAlias,
1085             hir::def::DefKind::Fn => TypeKind::Function,
1086             hir::def::DefKind::Const => TypeKind::Const,
1087             hir::def::DefKind::Static => TypeKind::Static,
1088             hir::def::DefKind::Macro(_) => TypeKind::Macro,
1089             _ => TypeKind::Foreign,
1090         }
1091     }
1092 }
1093
1094 impl Clean<Item> for hir::TraitItem<'_> {
1095     fn clean(&self, cx: &DocContext<'_>) -> Item {
1096         let inner = match self.kind {
1097             hir::TraitItemKind::Const(ref ty, default) => {
1098                 AssocConstItem(ty.clean(cx), default.map(|e| print_const_expr(cx, e)))
1099             }
1100             hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Provided(body)) => {
1101                 MethodItem((sig, &self.generics, body, None).clean(cx))
1102             }
1103             hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Required(ref names)) => {
1104                 let (generics, decl) = enter_impl_trait(cx, || {
1105                     (self.generics.clean(cx), (&*sig.decl, &names[..]).clean(cx))
1106                 });
1107                 let (all_types, ret_types) = get_all_types(&generics, &decl, cx);
1108                 TyMethodItem(TyMethod { header: sig.header, decl, generics, all_types, ret_types })
1109             }
1110             hir::TraitItemKind::Type(ref bounds, ref default) => {
1111                 AssocTypeItem(bounds.clean(cx), default.clean(cx))
1112             }
1113         };
1114         let local_did = cx.tcx.hir().local_def_id(self.hir_id);
1115         Item {
1116             name: Some(self.ident.name.clean(cx)),
1117             attrs: self.attrs.clean(cx),
1118             source: self.span.clean(cx),
1119             def_id: local_did.to_def_id(),
1120             visibility: Visibility::Inherited,
1121             stability: get_stability(cx, local_did.to_def_id()),
1122             deprecation: get_deprecation(cx, local_did.to_def_id()),
1123             inner,
1124         }
1125     }
1126 }
1127
1128 impl Clean<Item> for hir::ImplItem<'_> {
1129     fn clean(&self, cx: &DocContext<'_>) -> Item {
1130         let inner = match self.kind {
1131             hir::ImplItemKind::Const(ref ty, expr) => {
1132                 AssocConstItem(ty.clean(cx), Some(print_const_expr(cx, expr)))
1133             }
1134             hir::ImplItemKind::Fn(ref sig, body) => {
1135                 MethodItem((sig, &self.generics, body, Some(self.defaultness)).clean(cx))
1136             }
1137             hir::ImplItemKind::TyAlias(ref ty) => {
1138                 let type_ = ty.clean(cx);
1139                 let item_type = type_.def_id().and_then(|did| inline::build_ty(cx, did));
1140                 TypedefItem(Typedef { type_, generics: Generics::default(), item_type }, true)
1141             }
1142             hir::ImplItemKind::OpaqueTy(ref bounds) => OpaqueTyItem(
1143                 OpaqueTy { bounds: bounds.clean(cx), generics: Generics::default() },
1144                 true,
1145             ),
1146         };
1147         let local_did = cx.tcx.hir().local_def_id(self.hir_id);
1148         Item {
1149             name: Some(self.ident.name.clean(cx)),
1150             source: self.span.clean(cx),
1151             attrs: self.attrs.clean(cx),
1152             def_id: local_did.to_def_id(),
1153             visibility: self.vis.clean(cx),
1154             stability: get_stability(cx, local_did.to_def_id()),
1155             deprecation: get_deprecation(cx, local_did.to_def_id()),
1156             inner,
1157         }
1158     }
1159 }
1160
1161 impl Clean<Item> for ty::AssocItem {
1162     fn clean(&self, cx: &DocContext<'_>) -> Item {
1163         let inner = match self.kind {
1164             ty::AssocKind::Const => {
1165                 let ty = cx.tcx.type_of(self.def_id);
1166                 let default = if self.defaultness.has_value() {
1167                     Some(inline::print_inlined_const(cx, self.def_id))
1168                 } else {
1169                     None
1170                 };
1171                 AssocConstItem(ty.clean(cx), default)
1172             }
1173             ty::AssocKind::Fn => {
1174                 let generics =
1175                     (cx.tcx.generics_of(self.def_id), cx.tcx.explicit_predicates_of(self.def_id))
1176                         .clean(cx);
1177                 let sig = cx.tcx.fn_sig(self.def_id);
1178                 let mut decl = (self.def_id, sig).clean(cx);
1179
1180                 if self.fn_has_self_parameter {
1181                     let self_ty = match self.container {
1182                         ty::ImplContainer(def_id) => cx.tcx.type_of(def_id),
1183                         ty::TraitContainer(_) => cx.tcx.types.self_param,
1184                     };
1185                     let self_arg_ty = *sig.input(0).skip_binder();
1186                     if self_arg_ty == self_ty {
1187                         decl.inputs.values[0].type_ = Generic(String::from("Self"));
1188                     } else if let ty::Ref(_, ty, _) = self_arg_ty.kind {
1189                         if ty == self_ty {
1190                             match decl.inputs.values[0].type_ {
1191                                 BorrowedRef { ref mut type_, .. } => {
1192                                     **type_ = Generic(String::from("Self"))
1193                                 }
1194                                 _ => unreachable!(),
1195                             }
1196                         }
1197                     }
1198                 }
1199
1200                 let provided = match self.container {
1201                     ty::ImplContainer(_) => true,
1202                     ty::TraitContainer(_) => self.defaultness.has_value(),
1203                 };
1204                 let (all_types, ret_types) = get_all_types(&generics, &decl, cx);
1205                 if provided {
1206                     let constness = if is_min_const_fn(cx.tcx, self.def_id) {
1207                         hir::Constness::Const
1208                     } else {
1209                         hir::Constness::NotConst
1210                     };
1211                     let asyncness = cx.tcx.asyncness(self.def_id);
1212                     let defaultness = match self.container {
1213                         ty::ImplContainer(_) => Some(self.defaultness),
1214                         ty::TraitContainer(_) => None,
1215                     };
1216                     MethodItem(Method {
1217                         generics,
1218                         decl,
1219                         header: hir::FnHeader {
1220                             unsafety: sig.unsafety(),
1221                             abi: sig.abi(),
1222                             constness,
1223                             asyncness,
1224                         },
1225                         defaultness,
1226                         all_types,
1227                         ret_types,
1228                     })
1229                 } else {
1230                     TyMethodItem(TyMethod {
1231                         generics,
1232                         decl,
1233                         header: hir::FnHeader {
1234                             unsafety: sig.unsafety(),
1235                             abi: sig.abi(),
1236                             constness: hir::Constness::NotConst,
1237                             asyncness: hir::IsAsync::NotAsync,
1238                         },
1239                         all_types,
1240                         ret_types,
1241                     })
1242                 }
1243             }
1244             ty::AssocKind::Type => {
1245                 let my_name = self.ident.name.clean(cx);
1246
1247                 if let ty::TraitContainer(did) = self.container {
1248                     // When loading a cross-crate associated type, the bounds for this type
1249                     // are actually located on the trait/impl itself, so we need to load
1250                     // all of the generics from there and then look for bounds that are
1251                     // applied to this associated type in question.
1252                     let predicates = cx.tcx.explicit_predicates_of(did);
1253                     let generics = (cx.tcx.generics_of(did), predicates).clean(cx);
1254                     let mut bounds = generics
1255                         .where_predicates
1256                         .iter()
1257                         .filter_map(|pred| {
1258                             let (name, self_type, trait_, bounds) = match *pred {
1259                                 WherePredicate::BoundPredicate {
1260                                     ty: QPath { ref name, ref self_type, ref trait_ },
1261                                     ref bounds,
1262                                 } => (name, self_type, trait_, bounds),
1263                                 _ => return None,
1264                             };
1265                             if *name != my_name {
1266                                 return None;
1267                             }
1268                             match **trait_ {
1269                                 ResolvedPath { did, .. } if did == self.container.id() => {}
1270                                 _ => return None,
1271                             }
1272                             match **self_type {
1273                                 Generic(ref s) if *s == "Self" => {}
1274                                 _ => return None,
1275                             }
1276                             Some(bounds)
1277                         })
1278                         .flat_map(|i| i.iter().cloned())
1279                         .collect::<Vec<_>>();
1280                     // Our Sized/?Sized bound didn't get handled when creating the generics
1281                     // because we didn't actually get our whole set of bounds until just now
1282                     // (some of them may have come from the trait). If we do have a sized
1283                     // bound, we remove it, and if we don't then we add the `?Sized` bound
1284                     // at the end.
1285                     match bounds.iter().position(|b| b.is_sized_bound(cx)) {
1286                         Some(i) => {
1287                             bounds.remove(i);
1288                         }
1289                         None => bounds.push(GenericBound::maybe_sized(cx)),
1290                     }
1291
1292                     let ty = if self.defaultness.has_value() {
1293                         Some(cx.tcx.type_of(self.def_id))
1294                     } else {
1295                         None
1296                     };
1297
1298                     AssocTypeItem(bounds, ty.clean(cx))
1299                 } else {
1300                     let type_ = cx.tcx.type_of(self.def_id).clean(cx);
1301                     let item_type = type_.def_id().and_then(|did| inline::build_ty(cx, did));
1302                     TypedefItem(
1303                         Typedef {
1304                             type_,
1305                             generics: Generics { params: Vec::new(), where_predicates: Vec::new() },
1306                             item_type,
1307                         },
1308                         true,
1309                     )
1310                 }
1311             }
1312             ty::AssocKind::OpaqueTy => unimplemented!(),
1313         };
1314
1315         let visibility = match self.container {
1316             ty::ImplContainer(_) => self.vis.clean(cx),
1317             ty::TraitContainer(_) => Inherited,
1318         };
1319
1320         Item {
1321             name: Some(self.ident.name.clean(cx)),
1322             visibility,
1323             stability: get_stability(cx, self.def_id),
1324             deprecation: get_deprecation(cx, self.def_id),
1325             def_id: self.def_id,
1326             attrs: inline::load_attrs(cx, self.def_id).clean(cx),
1327             source: cx.tcx.def_span(self.def_id).clean(cx),
1328             inner,
1329         }
1330     }
1331 }
1332
1333 impl Clean<Type> for hir::Ty<'_> {
1334     fn clean(&self, cx: &DocContext<'_>) -> Type {
1335         use rustc_hir::*;
1336
1337         match self.kind {
1338             TyKind::Never => Never,
1339             TyKind::Ptr(ref m) => RawPointer(m.mutbl, box m.ty.clean(cx)),
1340             TyKind::Rptr(ref l, ref m) => {
1341                 let lifetime = if l.is_elided() { None } else { Some(l.clean(cx)) };
1342                 BorrowedRef { lifetime, mutability: m.mutbl, type_: box m.ty.clean(cx) }
1343             }
1344             TyKind::Slice(ref ty) => Slice(box ty.clean(cx)),
1345             TyKind::Array(ref ty, ref length) => {
1346                 let def_id = cx.tcx.hir().local_def_id(length.hir_id);
1347                 let length = match cx.tcx.const_eval_poly(def_id.to_def_id()) {
1348                     Ok(length) => {
1349                         print_const(cx, ty::Const::from_value(cx.tcx, length, cx.tcx.types.usize))
1350                     }
1351                     Err(_) => cx
1352                         .sess()
1353                         .source_map()
1354                         .span_to_snippet(cx.tcx.def_span(def_id))
1355                         .unwrap_or_else(|_| "_".to_string()),
1356                 };
1357                 Array(box ty.clean(cx), length)
1358             }
1359             TyKind::Tup(ref tys) => Tuple(tys.clean(cx)),
1360             TyKind::Def(item_id, _) => {
1361                 let item = cx.tcx.hir().expect_item(item_id.id);
1362                 if let hir::ItemKind::OpaqueTy(ref ty) = item.kind {
1363                     ImplTrait(ty.bounds.clean(cx))
1364                 } else {
1365                     unreachable!()
1366                 }
1367             }
1368             TyKind::Path(hir::QPath::Resolved(None, ref path)) => {
1369                 if let Res::Def(DefKind::TyParam, did) = path.res {
1370                     if let Some(new_ty) = cx.ty_substs.borrow().get(&did).cloned() {
1371                         return new_ty;
1372                     }
1373                     if let Some(bounds) = cx.impl_trait_bounds.borrow_mut().remove(&did.into()) {
1374                         return ImplTrait(bounds);
1375                     }
1376                 }
1377
1378                 let mut alias = None;
1379                 if let Res::Def(DefKind::TyAlias, def_id) = path.res {
1380                     // Substitute private type aliases
1381                     if let Some(def_id) = def_id.as_local() {
1382                         let hir_id = cx.tcx.hir().as_local_hir_id(def_id);
1383                         if !cx.renderinfo.borrow().access_levels.is_exported(def_id.to_def_id()) {
1384                             alias = Some(&cx.tcx.hir().expect_item(hir_id).kind);
1385                         }
1386                     }
1387                 };
1388
1389                 if let Some(&hir::ItemKind::TyAlias(ref ty, ref generics)) = alias {
1390                     let provided_params = &path.segments.last().expect("segments were empty");
1391                     let mut ty_substs = FxHashMap::default();
1392                     let mut lt_substs = FxHashMap::default();
1393                     let mut ct_substs = FxHashMap::default();
1394                     let generic_args = provided_params.generic_args();
1395                     {
1396                         let mut indices: GenericParamCount = Default::default();
1397                         for param in generics.params.iter() {
1398                             match param.kind {
1399                                 hir::GenericParamKind::Lifetime { .. } => {
1400                                     let mut j = 0;
1401                                     let lifetime =
1402                                         generic_args.args.iter().find_map(|arg| match arg {
1403                                             hir::GenericArg::Lifetime(lt) => {
1404                                                 if indices.lifetimes == j {
1405                                                     return Some(lt);
1406                                                 }
1407                                                 j += 1;
1408                                                 None
1409                                             }
1410                                             _ => None,
1411                                         });
1412                                     if let Some(lt) = lifetime.cloned() {
1413                                         if !lt.is_elided() {
1414                                             let lt_def_id = cx.tcx.hir().local_def_id(param.hir_id);
1415                                             lt_substs.insert(lt_def_id.to_def_id(), lt.clean(cx));
1416                                         }
1417                                     }
1418                                     indices.lifetimes += 1;
1419                                 }
1420                                 hir::GenericParamKind::Type { ref default, .. } => {
1421                                     let ty_param_def_id = cx.tcx.hir().local_def_id(param.hir_id);
1422                                     let mut j = 0;
1423                                     let type_ =
1424                                         generic_args.args.iter().find_map(|arg| match arg {
1425                                             hir::GenericArg::Type(ty) => {
1426                                                 if indices.types == j {
1427                                                     return Some(ty);
1428                                                 }
1429                                                 j += 1;
1430                                                 None
1431                                             }
1432                                             _ => None,
1433                                         });
1434                                     if let Some(ty) = type_ {
1435                                         ty_substs.insert(ty_param_def_id.to_def_id(), ty.clean(cx));
1436                                     } else if let Some(default) = *default {
1437                                         ty_substs
1438                                             .insert(ty_param_def_id.to_def_id(), default.clean(cx));
1439                                     }
1440                                     indices.types += 1;
1441                                 }
1442                                 hir::GenericParamKind::Const { .. } => {
1443                                     let const_param_def_id =
1444                                         cx.tcx.hir().local_def_id(param.hir_id);
1445                                     let mut j = 0;
1446                                     let const_ =
1447                                         generic_args.args.iter().find_map(|arg| match arg {
1448                                             hir::GenericArg::Const(ct) => {
1449                                                 if indices.consts == j {
1450                                                     return Some(ct);
1451                                                 }
1452                                                 j += 1;
1453                                                 None
1454                                             }
1455                                             _ => None,
1456                                         });
1457                                     if let Some(ct) = const_ {
1458                                         ct_substs
1459                                             .insert(const_param_def_id.to_def_id(), ct.clean(cx));
1460                                     }
1461                                     // FIXME(const_generics:defaults)
1462                                     indices.consts += 1;
1463                                 }
1464                             }
1465                         }
1466                     }
1467                     return cx.enter_alias(ty_substs, lt_substs, ct_substs, || ty.clean(cx));
1468                 }
1469                 resolve_type(cx, path.clean(cx), self.hir_id)
1470             }
1471             TyKind::Path(hir::QPath::Resolved(Some(ref qself), ref p)) => {
1472                 let segments = if p.is_global() { &p.segments[1..] } else { &p.segments };
1473                 let trait_segments = &segments[..segments.len() - 1];
1474                 let trait_path = self::Path {
1475                     global: p.is_global(),
1476                     res: Res::Def(
1477                         DefKind::Trait,
1478                         cx.tcx.associated_item(p.res.def_id()).container.id(),
1479                     ),
1480                     segments: trait_segments.clean(cx),
1481                 };
1482                 Type::QPath {
1483                     name: p.segments.last().expect("segments were empty").ident.name.clean(cx),
1484                     self_type: box qself.clean(cx),
1485                     trait_: box resolve_type(cx, trait_path, self.hir_id),
1486                 }
1487             }
1488             TyKind::Path(hir::QPath::TypeRelative(ref qself, ref segment)) => {
1489                 let mut res = Res::Err;
1490                 let ty = hir_ty_to_ty(cx.tcx, self);
1491                 if let ty::Projection(proj) = ty.kind {
1492                     res = Res::Def(DefKind::Trait, proj.trait_ref(cx.tcx).def_id);
1493                 }
1494                 let trait_path = hir::Path { span: self.span, res, segments: &[] };
1495                 Type::QPath {
1496                     name: segment.ident.name.clean(cx),
1497                     self_type: box qself.clean(cx),
1498                     trait_: box resolve_type(cx, trait_path.clean(cx), self.hir_id),
1499                 }
1500             }
1501             TyKind::TraitObject(ref bounds, ref lifetime) => {
1502                 match bounds[0].clean(cx).trait_ {
1503                     ResolvedPath { path, param_names: None, did, is_generic } => {
1504                         let mut bounds: Vec<self::GenericBound> = bounds[1..]
1505                             .iter()
1506                             .map(|bound| {
1507                                 self::GenericBound::TraitBound(
1508                                     bound.clean(cx),
1509                                     hir::TraitBoundModifier::None,
1510                                 )
1511                             })
1512                             .collect();
1513                         if !lifetime.is_elided() {
1514                             bounds.push(self::GenericBound::Outlives(lifetime.clean(cx)));
1515                         }
1516                         ResolvedPath { path, param_names: Some(bounds), did, is_generic }
1517                     }
1518                     _ => Infer, // shouldn't happen
1519                 }
1520             }
1521             TyKind::BareFn(ref barefn) => BareFunction(box barefn.clean(cx)),
1522             TyKind::Infer | TyKind::Err => Infer,
1523             TyKind::Typeof(..) => panic!("unimplemented type {:?}", self.kind),
1524         }
1525     }
1526 }
1527
1528 impl<'tcx> Clean<Type> for Ty<'tcx> {
1529     fn clean(&self, cx: &DocContext<'_>) -> Type {
1530         debug!("cleaning type: {:?}", self);
1531         match self.kind {
1532             ty::Never => Never,
1533             ty::Bool => Primitive(PrimitiveType::Bool),
1534             ty::Char => Primitive(PrimitiveType::Char),
1535             ty::Int(int_ty) => Primitive(int_ty.into()),
1536             ty::Uint(uint_ty) => Primitive(uint_ty.into()),
1537             ty::Float(float_ty) => Primitive(float_ty.into()),
1538             ty::Str => Primitive(PrimitiveType::Str),
1539             ty::Slice(ty) => Slice(box ty.clean(cx)),
1540             ty::Array(ty, n) => {
1541                 let mut n = cx.tcx.lift(&n).expect("array lift failed");
1542                 n = n.eval(cx.tcx, ty::ParamEnv::reveal_all());
1543                 let n = print_const(cx, n);
1544                 Array(box ty.clean(cx), n)
1545             }
1546             ty::RawPtr(mt) => RawPointer(mt.mutbl, box mt.ty.clean(cx)),
1547             ty::Ref(r, ty, mutbl) => {
1548                 BorrowedRef { lifetime: r.clean(cx), mutability: mutbl, type_: box ty.clean(cx) }
1549             }
1550             ty::FnDef(..) | ty::FnPtr(_) => {
1551                 let ty = cx.tcx.lift(self).expect("FnPtr lift failed");
1552                 let sig = ty.fn_sig(cx.tcx);
1553                 let local_def_id = cx.tcx.hir().local_def_id_from_node_id(ast::CRATE_NODE_ID);
1554                 BareFunction(box BareFunctionDecl {
1555                     unsafety: sig.unsafety(),
1556                     generic_params: Vec::new(),
1557                     decl: (local_def_id.to_def_id(), sig).clean(cx),
1558                     abi: sig.abi(),
1559                 })
1560             }
1561             ty::Adt(def, substs) => {
1562                 let did = def.did;
1563                 let kind = match def.adt_kind() {
1564                     AdtKind::Struct => TypeKind::Struct,
1565                     AdtKind::Union => TypeKind::Union,
1566                     AdtKind::Enum => TypeKind::Enum,
1567                 };
1568                 inline::record_extern_fqn(cx, did, kind);
1569                 let path = external_path(cx, cx.tcx.item_name(did), None, false, vec![], substs);
1570                 ResolvedPath { path, param_names: None, did, is_generic: false }
1571             }
1572             ty::Foreign(did) => {
1573                 inline::record_extern_fqn(cx, did, TypeKind::Foreign);
1574                 let path = external_path(
1575                     cx,
1576                     cx.tcx.item_name(did),
1577                     None,
1578                     false,
1579                     vec![],
1580                     InternalSubsts::empty(),
1581                 );
1582                 ResolvedPath { path, param_names: None, did, is_generic: false }
1583             }
1584             ty::Dynamic(ref obj, ref reg) => {
1585                 // HACK: pick the first `did` as the `did` of the trait object. Someone
1586                 // might want to implement "native" support for marker-trait-only
1587                 // trait objects.
1588                 let mut dids = obj.principal_def_id().into_iter().chain(obj.auto_traits());
1589                 let did = dids
1590                     .next()
1591                     .unwrap_or_else(|| panic!("found trait object `{:?}` with no traits?", self));
1592                 let substs = match obj.principal() {
1593                     Some(principal) => principal.skip_binder().substs,
1594                     // marker traits have no substs.
1595                     _ => cx.tcx.intern_substs(&[]),
1596                 };
1597
1598                 inline::record_extern_fqn(cx, did, TypeKind::Trait);
1599
1600                 let mut param_names = vec![];
1601                 if let Some(b) = reg.clean(cx) {
1602                     param_names.push(GenericBound::Outlives(b));
1603                 }
1604                 for did in dids {
1605                     let empty = cx.tcx.intern_substs(&[]);
1606                     let path =
1607                         external_path(cx, cx.tcx.item_name(did), Some(did), false, vec![], empty);
1608                     inline::record_extern_fqn(cx, did, TypeKind::Trait);
1609                     let bound = GenericBound::TraitBound(
1610                         PolyTrait {
1611                             trait_: ResolvedPath {
1612                                 path,
1613                                 param_names: None,
1614                                 did,
1615                                 is_generic: false,
1616                             },
1617                             generic_params: Vec::new(),
1618                         },
1619                         hir::TraitBoundModifier::None,
1620                     );
1621                     param_names.push(bound);
1622                 }
1623
1624                 let mut bindings = vec![];
1625                 for pb in obj.projection_bounds() {
1626                     bindings.push(TypeBinding {
1627                         name: cx.tcx.associated_item(pb.item_def_id()).ident.name.clean(cx),
1628                         kind: TypeBindingKind::Equality { ty: pb.skip_binder().ty.clean(cx) },
1629                     });
1630                 }
1631
1632                 let path =
1633                     external_path(cx, cx.tcx.item_name(did), Some(did), false, bindings, substs);
1634                 ResolvedPath { path, param_names: Some(param_names), did, is_generic: false }
1635             }
1636             ty::Tuple(ref t) => {
1637                 Tuple(t.iter().map(|t| t.expect_ty()).collect::<Vec<_>>().clean(cx))
1638             }
1639
1640             ty::Projection(ref data) => data.clean(cx),
1641
1642             ty::Param(ref p) => {
1643                 if let Some(bounds) = cx.impl_trait_bounds.borrow_mut().remove(&p.index.into()) {
1644                     ImplTrait(bounds)
1645                 } else {
1646                     Generic(p.name.to_string())
1647                 }
1648             }
1649
1650             ty::Opaque(def_id, substs) => {
1651                 // Grab the "TraitA + TraitB" from `impl TraitA + TraitB`,
1652                 // by looking up the projections associated with the def_id.
1653                 let predicates_of = cx.tcx.explicit_predicates_of(def_id);
1654                 let substs = cx.tcx.lift(&substs).expect("Opaque lift failed");
1655                 let bounds = predicates_of.instantiate(cx.tcx, substs);
1656                 let mut regions = vec![];
1657                 let mut has_sized = false;
1658                 let mut bounds = bounds
1659                     .predicates
1660                     .iter()
1661                     .filter_map(|predicate| {
1662                         let trait_ref = if let Some(tr) = predicate.to_opt_poly_trait_ref() {
1663                             tr
1664                         } else if let ty::PredicateKind::TypeOutlives(pred) = *predicate {
1665                             // these should turn up at the end
1666                             if let Some(r) = pred.skip_binder().1.clean(cx) {
1667                                 regions.push(GenericBound::Outlives(r));
1668                             }
1669                             return None;
1670                         } else {
1671                             return None;
1672                         };
1673
1674                         if let Some(sized) = cx.tcx.lang_items().sized_trait() {
1675                             if trait_ref.def_id() == sized {
1676                                 has_sized = true;
1677                                 return None;
1678                             }
1679                         }
1680
1681                         let bounds: Vec<_> = bounds
1682                             .predicates
1683                             .iter()
1684                             .filter_map(|pred| {
1685                                 if let ty::PredicateKind::Projection(proj) = *pred {
1686                                     let proj = proj.skip_binder();
1687                                     if proj.projection_ty.trait_ref(cx.tcx)
1688                                         == *trait_ref.skip_binder()
1689                                     {
1690                                         Some(TypeBinding {
1691                                             name: cx
1692                                                 .tcx
1693                                                 .associated_item(proj.projection_ty.item_def_id)
1694                                                 .ident
1695                                                 .name
1696                                                 .clean(cx),
1697                                             kind: TypeBindingKind::Equality {
1698                                                 ty: proj.ty.clean(cx),
1699                                             },
1700                                         })
1701                                     } else {
1702                                         None
1703                                     }
1704                                 } else {
1705                                     None
1706                                 }
1707                             })
1708                             .collect();
1709
1710                         Some((trait_ref, &bounds[..]).clean(cx))
1711                     })
1712                     .collect::<Vec<_>>();
1713                 bounds.extend(regions);
1714                 if !has_sized && !bounds.is_empty() {
1715                     bounds.insert(0, GenericBound::maybe_sized(cx));
1716                 }
1717                 ImplTrait(bounds)
1718             }
1719
1720             ty::Closure(..) | ty::Generator(..) => Tuple(vec![]), // FIXME(pcwalton)
1721
1722             ty::Bound(..) => panic!("Bound"),
1723             ty::Placeholder(..) => panic!("Placeholder"),
1724             ty::GeneratorWitness(..) => panic!("GeneratorWitness"),
1725             ty::Infer(..) => panic!("Infer"),
1726             ty::Error => panic!("Error"),
1727         }
1728     }
1729 }
1730
1731 impl<'tcx> Clean<Constant> for ty::Const<'tcx> {
1732     fn clean(&self, cx: &DocContext<'_>) -> Constant {
1733         Constant {
1734             type_: self.ty.clean(cx),
1735             expr: format!("{}", self),
1736             value: None,
1737             is_literal: false,
1738         }
1739     }
1740 }
1741
1742 impl Clean<Item> for hir::StructField<'_> {
1743     fn clean(&self, cx: &DocContext<'_>) -> Item {
1744         let local_did = cx.tcx.hir().local_def_id(self.hir_id);
1745
1746         Item {
1747             name: Some(self.ident.name).clean(cx),
1748             attrs: self.attrs.clean(cx),
1749             source: self.span.clean(cx),
1750             visibility: self.vis.clean(cx),
1751             stability: get_stability(cx, local_did.to_def_id()),
1752             deprecation: get_deprecation(cx, local_did.to_def_id()),
1753             def_id: local_did.to_def_id(),
1754             inner: StructFieldItem(self.ty.clean(cx)),
1755         }
1756     }
1757 }
1758
1759 impl Clean<Item> for ty::FieldDef {
1760     fn clean(&self, cx: &DocContext<'_>) -> Item {
1761         Item {
1762             name: Some(self.ident.name).clean(cx),
1763             attrs: cx.tcx.get_attrs(self.did).clean(cx),
1764             source: cx.tcx.def_span(self.did).clean(cx),
1765             visibility: self.vis.clean(cx),
1766             stability: get_stability(cx, self.did),
1767             deprecation: get_deprecation(cx, self.did),
1768             def_id: self.did,
1769             inner: StructFieldItem(cx.tcx.type_of(self.did).clean(cx)),
1770         }
1771     }
1772 }
1773
1774 impl Clean<Visibility> for hir::Visibility<'_> {
1775     fn clean(&self, cx: &DocContext<'_>) -> Visibility {
1776         match self.node {
1777             hir::VisibilityKind::Public => Visibility::Public,
1778             hir::VisibilityKind::Inherited => Visibility::Inherited,
1779             hir::VisibilityKind::Crate(_) => Visibility::Crate,
1780             hir::VisibilityKind::Restricted { ref path, .. } => {
1781                 let path = path.clean(cx);
1782                 let did = register_res(cx, path.res);
1783                 Visibility::Restricted(did, path)
1784             }
1785         }
1786     }
1787 }
1788
1789 impl Clean<Visibility> for ty::Visibility {
1790     fn clean(&self, _: &DocContext<'_>) -> Visibility {
1791         if *self == ty::Visibility::Public { Public } else { Inherited }
1792     }
1793 }
1794
1795 impl Clean<Item> for doctree::Struct<'_> {
1796     fn clean(&self, cx: &DocContext<'_>) -> Item {
1797         Item {
1798             name: Some(self.name.clean(cx)),
1799             attrs: self.attrs.clean(cx),
1800             source: self.whence.clean(cx),
1801             def_id: cx.tcx.hir().local_def_id(self.id).to_def_id(),
1802             visibility: self.vis.clean(cx),
1803             stability: cx.stability(self.id).clean(cx),
1804             deprecation: cx.deprecation(self.id).clean(cx),
1805             inner: StructItem(Struct {
1806                 struct_type: self.struct_type,
1807                 generics: self.generics.clean(cx),
1808                 fields: self.fields.clean(cx),
1809                 fields_stripped: false,
1810             }),
1811         }
1812     }
1813 }
1814
1815 impl Clean<Item> for doctree::Union<'_> {
1816     fn clean(&self, cx: &DocContext<'_>) -> Item {
1817         Item {
1818             name: Some(self.name.clean(cx)),
1819             attrs: self.attrs.clean(cx),
1820             source: self.whence.clean(cx),
1821             def_id: cx.tcx.hir().local_def_id(self.id).to_def_id(),
1822             visibility: self.vis.clean(cx),
1823             stability: cx.stability(self.id).clean(cx),
1824             deprecation: cx.deprecation(self.id).clean(cx),
1825             inner: UnionItem(Union {
1826                 struct_type: self.struct_type,
1827                 generics: self.generics.clean(cx),
1828                 fields: self.fields.clean(cx),
1829                 fields_stripped: false,
1830             }),
1831         }
1832     }
1833 }
1834
1835 impl Clean<VariantStruct> for rustc_hir::VariantData<'_> {
1836     fn clean(&self, cx: &DocContext<'_>) -> VariantStruct {
1837         VariantStruct {
1838             struct_type: doctree::struct_type_from_def(self),
1839             fields: self.fields().iter().map(|x| x.clean(cx)).collect(),
1840             fields_stripped: false,
1841         }
1842     }
1843 }
1844
1845 impl Clean<Item> for doctree::Enum<'_> {
1846     fn clean(&self, cx: &DocContext<'_>) -> Item {
1847         Item {
1848             name: Some(self.name.clean(cx)),
1849             attrs: self.attrs.clean(cx),
1850             source: self.whence.clean(cx),
1851             def_id: cx.tcx.hir().local_def_id(self.id).to_def_id(),
1852             visibility: self.vis.clean(cx),
1853             stability: cx.stability(self.id).clean(cx),
1854             deprecation: cx.deprecation(self.id).clean(cx),
1855             inner: EnumItem(Enum {
1856                 variants: self.variants.iter().map(|v| v.clean(cx)).collect(),
1857                 generics: self.generics.clean(cx),
1858                 variants_stripped: false,
1859             }),
1860         }
1861     }
1862 }
1863
1864 impl Clean<Item> for doctree::Variant<'_> {
1865     fn clean(&self, cx: &DocContext<'_>) -> Item {
1866         Item {
1867             name: Some(self.name.clean(cx)),
1868             attrs: self.attrs.clean(cx),
1869             source: self.whence.clean(cx),
1870             visibility: Inherited,
1871             stability: cx.stability(self.id).clean(cx),
1872             deprecation: cx.deprecation(self.id).clean(cx),
1873             def_id: cx.tcx.hir().local_def_id(self.id).to_def_id(),
1874             inner: VariantItem(Variant { kind: self.def.clean(cx) }),
1875         }
1876     }
1877 }
1878
1879 impl Clean<Item> for ty::VariantDef {
1880     fn clean(&self, cx: &DocContext<'_>) -> Item {
1881         let kind = match self.ctor_kind {
1882             CtorKind::Const => VariantKind::CLike,
1883             CtorKind::Fn => VariantKind::Tuple(
1884                 self.fields.iter().map(|f| cx.tcx.type_of(f.did).clean(cx)).collect(),
1885             ),
1886             CtorKind::Fictive => VariantKind::Struct(VariantStruct {
1887                 struct_type: doctree::Plain,
1888                 fields_stripped: false,
1889                 fields: self
1890                     .fields
1891                     .iter()
1892                     .map(|field| Item {
1893                         source: cx.tcx.def_span(field.did).clean(cx),
1894                         name: Some(field.ident.name.clean(cx)),
1895                         attrs: cx.tcx.get_attrs(field.did).clean(cx),
1896                         visibility: field.vis.clean(cx),
1897                         def_id: field.did,
1898                         stability: get_stability(cx, field.did),
1899                         deprecation: get_deprecation(cx, field.did),
1900                         inner: StructFieldItem(cx.tcx.type_of(field.did).clean(cx)),
1901                     })
1902                     .collect(),
1903             }),
1904         };
1905         Item {
1906             name: Some(self.ident.clean(cx)),
1907             attrs: inline::load_attrs(cx, self.def_id).clean(cx),
1908             source: cx.tcx.def_span(self.def_id).clean(cx),
1909             visibility: Inherited,
1910             def_id: self.def_id,
1911             inner: VariantItem(Variant { kind }),
1912             stability: get_stability(cx, self.def_id),
1913             deprecation: get_deprecation(cx, self.def_id),
1914         }
1915     }
1916 }
1917
1918 impl Clean<VariantKind> for hir::VariantData<'_> {
1919     fn clean(&self, cx: &DocContext<'_>) -> VariantKind {
1920         match self {
1921             hir::VariantData::Struct(..) => VariantKind::Struct(self.clean(cx)),
1922             hir::VariantData::Tuple(..) => {
1923                 VariantKind::Tuple(self.fields().iter().map(|x| x.ty.clean(cx)).collect())
1924             }
1925             hir::VariantData::Unit(..) => VariantKind::CLike,
1926         }
1927     }
1928 }
1929
1930 impl Clean<Span> for rustc_span::Span {
1931     fn clean(&self, cx: &DocContext<'_>) -> Span {
1932         if self.is_dummy() {
1933             return Span::empty();
1934         }
1935
1936         let sm = cx.sess().source_map();
1937         let filename = sm.span_to_filename(*self);
1938         let lo = sm.lookup_char_pos(self.lo());
1939         let hi = sm.lookup_char_pos(self.hi());
1940         Span {
1941             filename,
1942             cnum: lo.file.cnum,
1943             loline: lo.line,
1944             locol: lo.col.to_usize(),
1945             hiline: hi.line,
1946             hicol: hi.col.to_usize(),
1947             original: *self,
1948         }
1949     }
1950 }
1951
1952 impl Clean<Path> for hir::Path<'_> {
1953     fn clean(&self, cx: &DocContext<'_>) -> Path {
1954         Path {
1955             global: self.is_global(),
1956             res: self.res,
1957             segments: if self.is_global() { &self.segments[1..] } else { &self.segments }.clean(cx),
1958         }
1959     }
1960 }
1961
1962 impl Clean<GenericArgs> for hir::GenericArgs<'_> {
1963     fn clean(&self, cx: &DocContext<'_>) -> GenericArgs {
1964         if self.parenthesized {
1965             let output = self.bindings[0].ty().clean(cx);
1966             GenericArgs::Parenthesized {
1967                 inputs: self.inputs().clean(cx),
1968                 output: if output != Type::Tuple(Vec::new()) { Some(output) } else { None },
1969             }
1970         } else {
1971             let elide_lifetimes = self.args.iter().all(|arg| match arg {
1972                 hir::GenericArg::Lifetime(lt) => lt.is_elided(),
1973                 _ => true,
1974             });
1975             GenericArgs::AngleBracketed {
1976                 args: self
1977                     .args
1978                     .iter()
1979                     .filter_map(|arg| match arg {
1980                         hir::GenericArg::Lifetime(lt) if !elide_lifetimes => {
1981                             Some(GenericArg::Lifetime(lt.clean(cx)))
1982                         }
1983                         hir::GenericArg::Lifetime(_) => None,
1984                         hir::GenericArg::Type(ty) => Some(GenericArg::Type(ty.clean(cx))),
1985                         hir::GenericArg::Const(ct) => Some(GenericArg::Const(ct.clean(cx))),
1986                     })
1987                     .collect(),
1988                 bindings: self.bindings.clean(cx),
1989             }
1990         }
1991     }
1992 }
1993
1994 impl Clean<PathSegment> for hir::PathSegment<'_> {
1995     fn clean(&self, cx: &DocContext<'_>) -> PathSegment {
1996         PathSegment { name: self.ident.name.clean(cx), args: self.generic_args().clean(cx) }
1997     }
1998 }
1999
2000 impl Clean<String> for Ident {
2001     #[inline]
2002     fn clean(&self, cx: &DocContext<'_>) -> String {
2003         self.name.clean(cx)
2004     }
2005 }
2006
2007 impl Clean<String> for Symbol {
2008     #[inline]
2009     fn clean(&self, _: &DocContext<'_>) -> String {
2010         self.to_string()
2011     }
2012 }
2013
2014 impl Clean<Item> for doctree::Typedef<'_> {
2015     fn clean(&self, cx: &DocContext<'_>) -> Item {
2016         let type_ = self.ty.clean(cx);
2017         let item_type = type_.def_id().and_then(|did| inline::build_ty(cx, did));
2018         Item {
2019             name: Some(self.name.clean(cx)),
2020             attrs: self.attrs.clean(cx),
2021             source: self.whence.clean(cx),
2022             def_id: cx.tcx.hir().local_def_id(self.id).to_def_id(),
2023             visibility: self.vis.clean(cx),
2024             stability: cx.stability(self.id).clean(cx),
2025             deprecation: cx.deprecation(self.id).clean(cx),
2026             inner: TypedefItem(Typedef { type_, generics: self.gen.clean(cx), item_type }, false),
2027         }
2028     }
2029 }
2030
2031 impl Clean<Item> for doctree::OpaqueTy<'_> {
2032     fn clean(&self, cx: &DocContext<'_>) -> Item {
2033         Item {
2034             name: Some(self.name.clean(cx)),
2035             attrs: self.attrs.clean(cx),
2036             source: self.whence.clean(cx),
2037             def_id: cx.tcx.hir().local_def_id(self.id).to_def_id(),
2038             visibility: self.vis.clean(cx),
2039             stability: cx.stability(self.id).clean(cx),
2040             deprecation: cx.deprecation(self.id).clean(cx),
2041             inner: OpaqueTyItem(
2042                 OpaqueTy {
2043                     bounds: self.opaque_ty.bounds.clean(cx),
2044                     generics: self.opaque_ty.generics.clean(cx),
2045                 },
2046                 false,
2047             ),
2048         }
2049     }
2050 }
2051
2052 impl Clean<BareFunctionDecl> for hir::BareFnTy<'_> {
2053     fn clean(&self, cx: &DocContext<'_>) -> BareFunctionDecl {
2054         let (generic_params, decl) = enter_impl_trait(cx, || {
2055             (self.generic_params.clean(cx), (&*self.decl, &self.param_names[..]).clean(cx))
2056         });
2057         BareFunctionDecl { unsafety: self.unsafety, abi: self.abi, decl, generic_params }
2058     }
2059 }
2060
2061 impl Clean<Item> for doctree::Static<'_> {
2062     fn clean(&self, cx: &DocContext<'_>) -> Item {
2063         debug!("cleaning static {}: {:?}", self.name.clean(cx), self);
2064         Item {
2065             name: Some(self.name.clean(cx)),
2066             attrs: self.attrs.clean(cx),
2067             source: self.whence.clean(cx),
2068             def_id: cx.tcx.hir().local_def_id(self.id).to_def_id(),
2069             visibility: self.vis.clean(cx),
2070             stability: cx.stability(self.id).clean(cx),
2071             deprecation: cx.deprecation(self.id).clean(cx),
2072             inner: StaticItem(Static {
2073                 type_: self.type_.clean(cx),
2074                 mutability: self.mutability,
2075                 expr: print_const_expr(cx, self.expr),
2076             }),
2077         }
2078     }
2079 }
2080
2081 impl Clean<Item> for doctree::Constant<'_> {
2082     fn clean(&self, cx: &DocContext<'_>) -> Item {
2083         let def_id = cx.tcx.hir().local_def_id(self.id);
2084
2085         Item {
2086             name: Some(self.name.clean(cx)),
2087             attrs: self.attrs.clean(cx),
2088             source: self.whence.clean(cx),
2089             def_id: def_id.to_def_id(),
2090             visibility: self.vis.clean(cx),
2091             stability: cx.stability(self.id).clean(cx),
2092             deprecation: cx.deprecation(self.id).clean(cx),
2093             inner: ConstantItem(Constant {
2094                 type_: self.type_.clean(cx),
2095                 expr: print_const_expr(cx, self.expr),
2096                 value: print_evaluated_const(cx, def_id.to_def_id()),
2097                 is_literal: is_literal_expr(cx, self.expr.hir_id),
2098             }),
2099         }
2100     }
2101 }
2102
2103 impl Clean<ImplPolarity> for ty::ImplPolarity {
2104     fn clean(&self, _: &DocContext<'_>) -> ImplPolarity {
2105         match self {
2106             &ty::ImplPolarity::Positive |
2107             // FIXME: do we want to do something else here?
2108             &ty::ImplPolarity::Reservation => ImplPolarity::Positive,
2109             &ty::ImplPolarity::Negative => ImplPolarity::Negative,
2110         }
2111     }
2112 }
2113
2114 impl Clean<Vec<Item>> for doctree::Impl<'_> {
2115     fn clean(&self, cx: &DocContext<'_>) -> Vec<Item> {
2116         let mut ret = Vec::new();
2117         let trait_ = self.trait_.clean(cx);
2118         let items = self.items.iter().map(|ii| ii.clean(cx)).collect::<Vec<_>>();
2119         let def_id = cx.tcx.hir().local_def_id(self.id);
2120
2121         // If this impl block is an implementation of the Deref trait, then we
2122         // need to try inlining the target's inherent impl blocks as well.
2123         if trait_.def_id() == cx.tcx.lang_items().deref_trait() {
2124             build_deref_target_impls(cx, &items, &mut ret);
2125         }
2126
2127         let provided: FxHashSet<String> = trait_
2128             .def_id()
2129             .map(|did| {
2130                 cx.tcx.provided_trait_methods(did).map(|meth| meth.ident.to_string()).collect()
2131             })
2132             .unwrap_or_default();
2133
2134         let for_ = self.for_.clean(cx);
2135         let type_alias = for_.def_id().and_then(|did| match cx.tcx.def_kind(did) {
2136             DefKind::TyAlias => Some(cx.tcx.type_of(did).clean(cx)),
2137             _ => None,
2138         });
2139         let make_item = |trait_: Option<Type>, for_: Type, items: Vec<Item>| Item {
2140             name: None,
2141             attrs: self.attrs.clean(cx),
2142             source: self.whence.clean(cx),
2143             def_id: def_id.to_def_id(),
2144             visibility: self.vis.clean(cx),
2145             stability: cx.stability(self.id).clean(cx),
2146             deprecation: cx.deprecation(self.id).clean(cx),
2147             inner: ImplItem(Impl {
2148                 unsafety: self.unsafety,
2149                 generics: self.generics.clean(cx),
2150                 provided_trait_methods: provided.clone(),
2151                 trait_,
2152                 for_,
2153                 items,
2154                 polarity: Some(cx.tcx.impl_polarity(def_id).clean(cx)),
2155                 synthetic: false,
2156                 blanket_impl: None,
2157             }),
2158         };
2159         if let Some(type_alias) = type_alias {
2160             ret.push(make_item(trait_.clone(), type_alias, items.clone()));
2161         }
2162         ret.push(make_item(trait_, for_, items));
2163         ret
2164     }
2165 }
2166
2167 impl Clean<Vec<Item>> for doctree::ExternCrate<'_> {
2168     fn clean(&self, cx: &DocContext<'_>) -> Vec<Item> {
2169         let please_inline = self.vis.node.is_pub()
2170             && self.attrs.iter().any(|a| {
2171                 a.check_name(sym::doc)
2172                     && match a.meta_item_list() {
2173                         Some(l) => attr::list_contains_name(&l, sym::inline),
2174                         None => false,
2175                     }
2176             });
2177
2178         if please_inline {
2179             let mut visited = FxHashSet::default();
2180
2181             let res = Res::Def(DefKind::Mod, DefId { krate: self.cnum, index: CRATE_DEF_INDEX });
2182
2183             if let Some(items) =
2184                 inline::try_inline(cx, res, self.name, Some(self.attrs), &mut visited)
2185             {
2186                 return items;
2187             }
2188         }
2189
2190         vec![Item {
2191             name: None,
2192             attrs: self.attrs.clean(cx),
2193             source: self.whence.clean(cx),
2194             def_id: DefId { krate: self.cnum, index: CRATE_DEF_INDEX },
2195             visibility: self.vis.clean(cx),
2196             stability: None,
2197             deprecation: None,
2198             inner: ExternCrateItem(self.name.clean(cx), self.path.clone()),
2199         }]
2200     }
2201 }
2202
2203 impl Clean<Vec<Item>> for doctree::Import<'_> {
2204     fn clean(&self, cx: &DocContext<'_>) -> Vec<Item> {
2205         // We consider inlining the documentation of `pub use` statements, but we
2206         // forcefully don't inline if this is not public or if the
2207         // #[doc(no_inline)] attribute is present.
2208         // Don't inline doc(hidden) imports so they can be stripped at a later stage.
2209         let mut denied = !self.vis.node.is_pub()
2210             || self.attrs.iter().any(|a| {
2211                 a.check_name(sym::doc)
2212                     && match a.meta_item_list() {
2213                         Some(l) => {
2214                             attr::list_contains_name(&l, sym::no_inline)
2215                                 || attr::list_contains_name(&l, sym::hidden)
2216                         }
2217                         None => false,
2218                     }
2219             });
2220         // Also check whether imports were asked to be inlined, in case we're trying to re-export a
2221         // crate in Rust 2018+
2222         let please_inline = self.attrs.lists(sym::doc).has_word(sym::inline);
2223         let path = self.path.clean(cx);
2224         let inner = if self.glob {
2225             if !denied {
2226                 let mut visited = FxHashSet::default();
2227                 if let Some(items) = inline::try_inline_glob(cx, path.res, &mut visited) {
2228                     return items;
2229                 }
2230             }
2231
2232             Import::Glob(resolve_use_source(cx, path))
2233         } else {
2234             let name = self.name;
2235             if !please_inline {
2236                 if let Res::Def(DefKind::Mod, did) = path.res {
2237                     if !did.is_local() && did.index == CRATE_DEF_INDEX {
2238                         // if we're `pub use`ing an extern crate root, don't inline it unless we
2239                         // were specifically asked for it
2240                         denied = true;
2241                     }
2242                 }
2243             }
2244             if !denied {
2245                 let mut visited = FxHashSet::default();
2246                 if let Some(items) =
2247                     inline::try_inline(cx, path.res, name, Some(self.attrs), &mut visited)
2248                 {
2249                     return items;
2250                 }
2251             }
2252             Import::Simple(name.clean(cx), resolve_use_source(cx, path))
2253         };
2254
2255         vec![Item {
2256             name: None,
2257             attrs: self.attrs.clean(cx),
2258             source: self.whence.clean(cx),
2259             def_id: cx.tcx.hir().local_def_id_from_node_id(ast::CRATE_NODE_ID).to_def_id(),
2260             visibility: self.vis.clean(cx),
2261             stability: None,
2262             deprecation: None,
2263             inner: ImportItem(inner),
2264         }]
2265     }
2266 }
2267
2268 impl Clean<Item> for doctree::ForeignItem<'_> {
2269     fn clean(&self, cx: &DocContext<'_>) -> Item {
2270         let inner = match self.kind {
2271             hir::ForeignItemKind::Fn(ref decl, ref names, ref generics) => {
2272                 let abi = cx.tcx.hir().get_foreign_abi(self.id);
2273                 let (generics, decl) =
2274                     enter_impl_trait(cx, || (generics.clean(cx), (&**decl, &names[..]).clean(cx)));
2275                 let (all_types, ret_types) = get_all_types(&generics, &decl, cx);
2276                 ForeignFunctionItem(Function {
2277                     decl,
2278                     generics,
2279                     header: hir::FnHeader {
2280                         unsafety: hir::Unsafety::Unsafe,
2281                         abi,
2282                         constness: hir::Constness::NotConst,
2283                         asyncness: hir::IsAsync::NotAsync,
2284                     },
2285                     all_types,
2286                     ret_types,
2287                 })
2288             }
2289             hir::ForeignItemKind::Static(ref ty, mutbl) => ForeignStaticItem(Static {
2290                 type_: ty.clean(cx),
2291                 mutability: *mutbl,
2292                 expr: String::new(),
2293             }),
2294             hir::ForeignItemKind::Type => ForeignTypeItem,
2295         };
2296
2297         Item {
2298             name: Some(self.name.clean(cx)),
2299             attrs: self.attrs.clean(cx),
2300             source: self.whence.clean(cx),
2301             def_id: cx.tcx.hir().local_def_id(self.id).to_def_id(),
2302             visibility: self.vis.clean(cx),
2303             stability: cx.stability(self.id).clean(cx),
2304             deprecation: cx.deprecation(self.id).clean(cx),
2305             inner,
2306         }
2307     }
2308 }
2309
2310 impl Clean<Item> for doctree::Macro<'_> {
2311     fn clean(&self, cx: &DocContext<'_>) -> Item {
2312         let name = self.name.clean(cx);
2313         Item {
2314             name: Some(name.clone()),
2315             attrs: self.attrs.clean(cx),
2316             source: self.whence.clean(cx),
2317             visibility: Public,
2318             stability: cx.stability(self.hid).clean(cx),
2319             deprecation: cx.deprecation(self.hid).clean(cx),
2320             def_id: self.def_id,
2321             inner: MacroItem(Macro {
2322                 source: format!(
2323                     "macro_rules! {} {{\n{}}}",
2324                     name,
2325                     self.matchers
2326                         .iter()
2327                         .map(|span| { format!("    {} => {{ ... }};\n", span.to_src(cx)) })
2328                         .collect::<String>()
2329                 ),
2330                 imported_from: self.imported_from.clean(cx),
2331             }),
2332         }
2333     }
2334 }
2335
2336 impl Clean<Item> for doctree::ProcMacro<'_> {
2337     fn clean(&self, cx: &DocContext<'_>) -> Item {
2338         Item {
2339             name: Some(self.name.clean(cx)),
2340             attrs: self.attrs.clean(cx),
2341             source: self.whence.clean(cx),
2342             visibility: Public,
2343             stability: cx.stability(self.id).clean(cx),
2344             deprecation: cx.deprecation(self.id).clean(cx),
2345             def_id: cx.tcx.hir().local_def_id(self.id).to_def_id(),
2346             inner: ProcMacroItem(ProcMacro { kind: self.kind, helpers: self.helpers.clean(cx) }),
2347         }
2348     }
2349 }
2350
2351 impl Clean<Stability> for attr::Stability {
2352     fn clean(&self, _: &DocContext<'_>) -> Stability {
2353         Stability {
2354             level: stability::StabilityLevel::from_attr_level(&self.level),
2355             feature: Some(self.feature.to_string()).filter(|f| !f.is_empty()),
2356             since: match self.level {
2357                 attr::Stable { ref since } => since.to_string(),
2358                 _ => String::new(),
2359             },
2360             deprecation: self.rustc_depr.as_ref().map(|d| Deprecation {
2361                 note: Some(d.reason.to_string()).filter(|r| !r.is_empty()),
2362                 since: Some(d.since.to_string()).filter(|d| !d.is_empty()),
2363             }),
2364             unstable_reason: match self.level {
2365                 attr::Unstable { reason: Some(ref reason), .. } => Some(reason.to_string()),
2366                 _ => None,
2367             },
2368             issue: match self.level {
2369                 attr::Unstable { issue, .. } => issue,
2370                 _ => None,
2371             },
2372         }
2373     }
2374 }
2375
2376 impl Clean<Deprecation> for attr::Deprecation {
2377     fn clean(&self, _: &DocContext<'_>) -> Deprecation {
2378         Deprecation {
2379             since: self.since.map(|s| s.to_string()).filter(|s| !s.is_empty()),
2380             note: self.note.map(|n| n.to_string()).filter(|n| !n.is_empty()),
2381         }
2382     }
2383 }
2384
2385 impl Clean<TypeBinding> for hir::TypeBinding<'_> {
2386     fn clean(&self, cx: &DocContext<'_>) -> TypeBinding {
2387         TypeBinding { name: self.ident.name.clean(cx), kind: self.kind.clean(cx) }
2388     }
2389 }
2390
2391 impl Clean<TypeBindingKind> for hir::TypeBindingKind<'_> {
2392     fn clean(&self, cx: &DocContext<'_>) -> TypeBindingKind {
2393         match *self {
2394             hir::TypeBindingKind::Equality { ref ty } => {
2395                 TypeBindingKind::Equality { ty: ty.clean(cx) }
2396             }
2397             hir::TypeBindingKind::Constraint { ref bounds } => {
2398                 TypeBindingKind::Constraint { bounds: bounds.iter().map(|b| b.clean(cx)).collect() }
2399             }
2400         }
2401     }
2402 }
2403
2404 enum SimpleBound {
2405     TraitBound(Vec<PathSegment>, Vec<SimpleBound>, Vec<GenericParamDef>, hir::TraitBoundModifier),
2406     Outlives(Lifetime),
2407 }
2408
2409 impl From<GenericBound> for SimpleBound {
2410     fn from(bound: GenericBound) -> Self {
2411         match bound.clone() {
2412             GenericBound::Outlives(l) => SimpleBound::Outlives(l),
2413             GenericBound::TraitBound(t, mod_) => match t.trait_ {
2414                 Type::ResolvedPath { path, param_names, .. } => SimpleBound::TraitBound(
2415                     path.segments,
2416                     param_names.map_or_else(Vec::new, |v| {
2417                         v.iter().map(|p| SimpleBound::from(p.clone())).collect()
2418                     }),
2419                     t.generic_params,
2420                     mod_,
2421                 ),
2422                 _ => panic!("Unexpected bound {:?}", bound),
2423             },
2424         }
2425     }
2426 }