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