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 as 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::bug;
  21 use rustc_middle::middle::resolve_lifetime as rl;
  22 use rustc_middle::middle::stability;
  23 use rustc_middle::ty::fold::TypeFolder;
  24 use rustc_middle::ty::subst::InternalSubsts;
  25 use rustc_middle::ty::{self, AdtKind, Lift, Ty, TyCtxt};
  26 use rustc_mir::const_eval::{is_const_fn, is_min_const_fn, is_unstable_const_fn};
  27 use rustc_span::hygiene::MacroKind;
  28 use rustc_span::symbol::{kw, sym, Ident, Symbol};
  29 use rustc_span::{self, Pos};
  30 use rustc_typeck::hir_ty_to_ty;
  31
  32 use std::collections::hash_map::Entry;
  33 use std::default::Default;
  34 use std::hash::Hash;
  35 use std::rc::Rc;
  36 use std::{mem, vec};
  37
  38 use crate::core::{self, DocContext, ImplTraitParam};
  39 use crate::doctree;
  40
  41 use utils::*;
  42
  43 pub use utils::{get_auto_trait_and_blanket_impls, krate, register_res};
  44
  45 pub use self::types::FnRetTy::*;
  46 pub use self::types::ItemEnum::*;
  47 pub use self::types::SelfTy::*;
  48 pub use self::types::Type::*;
  49 pub use self::types::Visibility::{Inherited, Public};
  50 pub use self::types::*;
  51
  52 const FN_OUTPUT_NAME: &str = "Output";
  53
  54 pub trait Clean<T> {
  55     fn clean(&self, cx: &DocContext<'_>) -> T;
  56 }
  57
  58 impl<T: Clean<U>, U> Clean<Vec<U>> for [T] {
  59     fn clean(&self, cx: &DocContext<'_>) -> Vec<U> {
  60         self.iter().map(|x| x.clean(cx)).collect()
  61     }
  62 }
  63
  64 impl<T: Clean<U>, U, V: Idx> Clean<IndexVec<V, U>> for IndexVec<V, T> {
  65     fn clean(&self, cx: &DocContext<'_>) -> IndexVec<V, U> {
  66         self.iter().map(|x| x.clean(cx)).collect()
  67     }
  68 }
  69
  70 impl<T: Clean<U>, U> Clean<U> for &T {
  71     fn clean(&self, cx: &DocContext<'_>) -> U {
  72         (**self).clean(cx)
  73     }
  74 }
  75
  76 impl<T: Clean<U>, U> Clean<U> for Rc<T> {
  77     fn clean(&self, cx: &DocContext<'_>) -> U {
  78         (**self).clean(cx)
  79     }
  80 }
  81
  82 impl<T: Clean<U>, U> Clean<Option<U>> for Option<T> {
  83     fn clean(&self, cx: &DocContext<'_>) -> Option<U> {
  84         self.as_ref().map(|v| v.clean(cx))
  85     }
  86 }
  87
  88 impl Clean<ExternalCrate> for CrateNum {
  89     fn clean(&self, cx: &DocContext<'_>) -> ExternalCrate {
  90         let root = DefId { krate: *self, index: CRATE_DEF_INDEX };
  91         let krate_span = cx.tcx.def_span(root);
  92         let krate_src = cx.sess().source_map().span_to_filename(krate_span);
  93
  94         // Collect all inner modules which are tagged as implementations of
  95         // primitives.
  96         //
  97         // Note that this loop only searches the top-level items of the crate,
  98         // and this is intentional. If we were to search the entire crate for an
  99         // item tagged with `#[doc(primitive)]` then we would also have to
 100         // search the entirety of external modules for items tagged
 101         // `#[doc(primitive)]`, which is a pretty inefficient process (decoding
 102         // all that metadata unconditionally).
 103         //
 104         // In order to keep the metadata load under control, the
 105         // `#[doc(primitive)]` feature is explicitly designed to only allow the
 106         // primitive tags to show up as the top level items in a crate.
 107         //
 108         // Also note that this does not attempt to deal with modules tagged
 109         // duplicately for the same primitive. This is handled later on when
 110         // rendering by delegating everything to a hash map.
 111         let as_primitive = |res: Res| {
 112             if let Res::Def(DefKind::Mod, def_id) = res {
 113                 let attrs = cx.tcx.get_attrs(def_id).clean(cx);
 114                 let mut prim = None;
 115                 for attr in attrs.lists(sym::doc) {
 116                     if let Some(v) = attr.value_str() {
 117                         if attr.has_name(sym::primitive) {
 118                             prim = PrimitiveType::from_symbol(v);
 119                             if prim.is_some() {
 120                                 break;
 121                             }
 122                             // FIXME: should warn on unknown primitives?
 123                         }
 124                     }
 125                 }
 126                 return prim.map(|p| (def_id, p, attrs));
 127             }
 128             None
 129         };
 130         let primitives = if root.is_local() {
 131             cx.tcx
 132                 .hir()
 133                 .krate()
 134                 .item
 135                 .module
 136                 .item_ids
 137                 .iter()
 138                 .filter_map(|&id| {
 139                     let item = cx.tcx.hir().expect_item(id.id);
 140                     match item.kind {
 141                         hir::ItemKind::Mod(_) => as_primitive(Res::Def(
 142                             DefKind::Mod,
 143                             cx.tcx.hir().local_def_id(id.id).to_def_id(),
 144                         )),
 145                         hir::ItemKind::Use(ref path, hir::UseKind::Single)
 146                             if item.vis.node.is_pub() =>
 147                         {
 148                             as_primitive(path.res).map(|(_, prim, attrs)| {
 149                                 // Pretend the primitive is local.
 150                                 (cx.tcx.hir().local_def_id(id.id).to_def_id(), prim, attrs)
 151                             })
 152                         }
 153                         _ => None,
 154                     }
 155                 })
 156                 .collect()
 157         } else {
 158             cx.tcx
 159                 .item_children(root)
 160                 .iter()
 161                 .map(|item| item.res)
 162                 .filter_map(as_primitive)
 163                 .collect()
 164         };
 165
 166         let as_keyword = |res: Res| {
 167             if let Res::Def(DefKind::Mod, def_id) = res {
 168                 let attrs = cx.tcx.get_attrs(def_id).clean(cx);
 169                 let mut keyword = None;
 170                 for attr in attrs.lists(sym::doc) {
 171                     if let Some(v) = attr.value_str() {
 172                         if attr.has_name(sym::keyword) {
 173                             if v.is_doc_keyword() {
 174                                 keyword = Some(v.to_string());
 175                                 break;
 176                             }
 177                             // FIXME: should warn on unknown keywords?
 178                         }
 179                     }
 180                 }
 181                 return keyword.map(|p| (def_id, p, attrs));
 182             }
 183             None
 184         };
 185         let keywords = if root.is_local() {
 186             cx.tcx
 187                 .hir()
 188                 .krate()
 189                 .item
 190                 .module
 191                 .item_ids
 192                 .iter()
 193                 .filter_map(|&id| {
 194                     let item = cx.tcx.hir().expect_item(id.id);
 195                     match item.kind {
 196                         hir::ItemKind::Mod(_) => as_keyword(Res::Def(
 197                             DefKind::Mod,
 198                             cx.tcx.hir().local_def_id(id.id).to_def_id(),
 199                         )),
 200                         hir::ItemKind::Use(ref path, hir::UseKind::Single)
 201                             if item.vis.node.is_pub() =>
 202                         {
 203                             as_keyword(path.res).map(|(_, prim, attrs)| {
 204                                 (cx.tcx.hir().local_def_id(id.id).to_def_id(), prim, attrs)
 205                             })
 206                         }
 207                         _ => None,
 208                     }
 209                 })
 210                 .collect()
 211         } else {
 212             cx.tcx.item_children(root).iter().map(|item| item.res).filter_map(as_keyword).collect()
 213         };
 214
 215         ExternalCrate {
 216             name: cx.tcx.crate_name(*self).to_string(),
 217             src: krate_src,
 218             attrs: cx.tcx.get_attrs(root).clean(cx),
 219             primitives,
 220             keywords,
 221         }
 222     }
 223 }
 224
 225 impl Clean<Item> for doctree::Module<'_> {
 226     fn clean(&self, cx: &DocContext<'_>) -> Item {
 227         let name = if self.name.is_some() {
 228             self.name.expect("No name provided").clean(cx)
 229         } else {
 230             String::new()
 231         };
 232
 233         // maintain a stack of mod ids, for doc comment path resolution
 234         // but we also need to resolve the module's own docs based on whether its docs were written
 235         // inside or outside the module, so check for that
 236         let attrs = self.attrs.clean(cx);
 237
 238         let mut items: Vec<Item> = vec![];
 239         items.extend(self.extern_crates.iter().flat_map(|x| x.clean(cx)));
 240         items.extend(self.imports.iter().flat_map(|x| x.clean(cx)));
 241         items.extend(self.structs.iter().map(|x| x.clean(cx)));
 242         items.extend(self.unions.iter().map(|x| x.clean(cx)));
 243         items.extend(self.enums.iter().map(|x| x.clean(cx)));
 244         items.extend(self.fns.iter().map(|x| x.clean(cx)));
 245         items.extend(self.foreigns.iter().map(|x| x.clean(cx)));
 246         items.extend(self.mods.iter().map(|x| x.clean(cx)));
 247         items.extend(self.typedefs.iter().map(|x| x.clean(cx)));
 248         items.extend(self.opaque_tys.iter().map(|x| x.clean(cx)));
 249         items.extend(self.statics.iter().map(|x| x.clean(cx)));
 250         items.extend(self.constants.iter().map(|x| x.clean(cx)));
 251         items.extend(self.traits.iter().map(|x| x.clean(cx)));
 252         items.extend(self.impls.iter().flat_map(|x| x.clean(cx)));
 253         items.extend(self.macros.iter().map(|x| x.clean(cx)));
 254         items.extend(self.proc_macros.iter().map(|x| x.clean(cx)));
 255         items.extend(self.trait_aliases.iter().map(|x| x.clean(cx)));
 256
 257         // determine if we should display the inner contents or
 258         // the outer `mod` item for the source code.
 259         let whence = {
 260             let sm = cx.sess().source_map();
 261             let outer = sm.lookup_char_pos(self.where_outer.lo());
 262             let inner = sm.lookup_char_pos(self.where_inner.lo());
 263             if outer.file.start_pos == inner.file.start_pos {
 264                 // mod foo { ... }
 265                 self.where_outer
 266             } else {
 267                 // mod foo; (and a separate SourceFile for the contents)
 268                 self.where_inner
 269             }
 270         };
 271
 272         Item {
 273             name: Some(name),
 274             attrs,
 275             source: whence.clean(cx),
 276             visibility: self.vis.clean(cx),
 277             stability: cx.stability(self.id).clean(cx),
 278             deprecation: cx.deprecation(self.id).clean(cx),
 279             def_id: cx.tcx.hir().local_def_id(self.id).to_def_id(),
 280             inner: ModuleItem(Module { is_crate: self.is_crate, items }),
 281         }
 282     }
 283 }
 284
 285 impl Clean<Attributes> for [ast::Attribute] {
 286     fn clean(&self, cx: &DocContext<'_>) -> Attributes {
 287         Attributes::from_ast(cx.sess().diagnostic(), self)
 288     }
 289 }
 290
 291 impl Clean<GenericBound> for hir::GenericBound<'_> {
 292     fn clean(&self, cx: &DocContext<'_>) -> GenericBound {
 293         match *self {
 294             hir::GenericBound::Outlives(lt) => GenericBound::Outlives(lt.clean(cx)),
 295             hir::GenericBound::LangItemTrait(lang_item, span, _, generic_args) => {
 296                 let def_id = cx.tcx.require_lang_item(lang_item, Some(span));
 297
 298                 let trait_ref = ty::TraitRef::identity(cx.tcx, def_id);
 299
 300                 let generic_args = generic_args.clean(cx);
 301                 let bindings = match generic_args {
 302                     GenericArgs::AngleBracketed { bindings, .. } => bindings,
 303                     _ => bug!("clean: parenthesized `GenericBound::LangItemTrait`"),
 304                 };
 305
 306                 GenericBound::TraitBound(
 307                     PolyTrait { trait_: (trait_ref, &*bindings).clean(cx), generic_params: vec![] },
 308                     hir::TraitBoundModifier::None,
 309                 )
 310             }
 311             hir::GenericBound::Trait(ref t, modifier) => {
 312                 GenericBound::TraitBound(t.clean(cx), modifier)
 313             }
 314         }
 315     }
 316 }
 317
 318 impl Clean<Type> for (ty::TraitRef<'_>, &[TypeBinding]) {
 319     fn clean(&self, cx: &DocContext<'_>) -> Type {
 320         let (trait_ref, bounds) = *self;
 321         inline::record_extern_fqn(cx, trait_ref.def_id, TypeKind::Trait);
 322         let path = external_path(
 323             cx,
 324             cx.tcx.item_name(trait_ref.def_id),
 325             Some(trait_ref.def_id),
 326             true,
 327             bounds.to_vec(),
 328             trait_ref.substs,
 329         );
 330
 331         debug!("ty::TraitRef\n  subst: {:?}\n", trait_ref.substs);
 332
 333         ResolvedPath { path, param_names: None, did: trait_ref.def_id, is_generic: false }
 334     }
 335 }
 336
 337 impl<'tcx> Clean<GenericBound> for ty::TraitRef<'tcx> {
 338     fn clean(&self, cx: &DocContext<'_>) -> GenericBound {
 339         GenericBound::TraitBound(
 340             PolyTrait { trait_: (*self, &[][..]).clean(cx), generic_params: vec![] },
 341             hir::TraitBoundModifier::None,
 342         )
 343     }
 344 }
 345
 346 impl Clean<GenericBound> for (ty::PolyTraitRef<'_>, &[TypeBinding]) {
 347     fn clean(&self, cx: &DocContext<'_>) -> GenericBound {
 348         let (poly_trait_ref, bounds) = *self;
 349         let poly_trait_ref = poly_trait_ref.lift_to_tcx(cx.tcx).unwrap();
 350
 351         // collect any late bound regions
 352         let late_bound_regions: Vec<_> = cx
 353             .tcx
 354             .collect_referenced_late_bound_regions(&poly_trait_ref)
 355             .into_iter()
 356             .filter_map(|br| match br {
 357                 ty::BrNamed(_, name) => Some(GenericParamDef {
 358                     name: name.to_string(),
 359                     kind: GenericParamDefKind::Lifetime,
 360                 }),
 361                 _ => None,
 362             })
 363             .collect();
 364
 365         GenericBound::TraitBound(
 366             PolyTrait {
 367                 trait_: (poly_trait_ref.skip_binder(), bounds).clean(cx),
 368                 generic_params: late_bound_regions,
 369             },
 370             hir::TraitBoundModifier::None,
 371         )
 372     }
 373 }
 374
 375 impl<'tcx> Clean<GenericBound> for ty::PolyTraitRef<'tcx> {
 376     fn clean(&self, cx: &DocContext<'_>) -> GenericBound {
 377         (*self, &[][..]).clean(cx)
 378     }
 379 }
 380
 381 impl<'tcx> Clean<Option<Vec<GenericBound>>> for InternalSubsts<'tcx> {
 382     fn clean(&self, cx: &DocContext<'_>) -> Option<Vec<GenericBound>> {
 383         let mut v = Vec::new();
 384         v.extend(self.regions().filter_map(|r| r.clean(cx)).map(GenericBound::Outlives));
 385         v.extend(self.types().map(|t| {
 386             GenericBound::TraitBound(
 387                 PolyTrait { trait_: t.clean(cx), generic_params: Vec::new() },
 388                 hir::TraitBoundModifier::None,
 389             )
 390         }));
 391         if !v.is_empty() { Some(v) } else { None }
 392     }
 393 }
 394
 395 impl Clean<Lifetime> for hir::Lifetime {
 396     fn clean(&self, cx: &DocContext<'_>) -> Lifetime {
 397         let def = cx.tcx.named_region(self.hir_id);
 398         match def {
 399             Some(
 400                 rl::Region::EarlyBound(_, node_id, _)
 401                 | rl::Region::LateBound(_, node_id, _)
 402                 | rl::Region::Free(_, node_id),
 403             ) => {
 404                 if let Some(lt) = cx.lt_substs.borrow().get(&node_id).cloned() {
 405                     return lt;
 406                 }
 407             }
 408             _ => {}
 409         }
 410         Lifetime(self.name.ident().to_string())
 411     }
 412 }
 413
 414 impl Clean<Lifetime> for hir::GenericParam<'_> {
 415     fn clean(&self, _: &DocContext<'_>) -> Lifetime {
 416         match self.kind {
 417             hir::GenericParamKind::Lifetime { .. } => {
 418                 if !self.bounds.is_empty() {
 419                     let mut bounds = self.bounds.iter().map(|bound| match bound {
 420                         hir::GenericBound::Outlives(lt) => lt,
 421                         _ => panic!(),
 422                     });
 423                     let name = bounds.next().expect("no more bounds").name.ident();
 424                     let mut s = format!("{}: {}", self.name.ident(), name);
 425                     for bound in bounds {
 426                         s.push_str(&format!(" + {}", bound.name.ident()));
 427                     }
 428                     Lifetime(s)
 429                 } else {
 430                     Lifetime(self.name.ident().to_string())
 431                 }
 432             }
 433             _ => panic!(),
 434         }
 435     }
 436 }
 437
 438 impl Clean<Constant> for hir::ConstArg {
 439     fn clean(&self, cx: &DocContext<'_>) -> Constant {
 440         Constant {
 441             type_: cx
 442                 .tcx
 443                 .type_of(cx.tcx.hir().body_owner_def_id(self.value.body).to_def_id())
 444                 .clean(cx),
 445             expr: print_const_expr(cx, self.value.body),
 446             value: None,
 447             is_literal: is_literal_expr(cx, self.value.body.hir_id),
 448         }
 449     }
 450 }
 451
 452 impl Clean<Lifetime> for ty::GenericParamDef {
 453     fn clean(&self, _cx: &DocContext<'_>) -> Lifetime {
 454         Lifetime(self.name.to_string())
 455     }
 456 }
 457
 458 impl Clean<Option<Lifetime>> for ty::RegionKind {
 459     fn clean(&self, cx: &DocContext<'_>) -> Option<Lifetime> {
 460         match *self {
 461             ty::ReStatic => Some(Lifetime::statik()),
 462             ty::ReLateBound(_, ty::BrNamed(_, name)) => Some(Lifetime(name.to_string())),
 463             ty::ReEarlyBound(ref data) => Some(Lifetime(data.name.clean(cx))),
 464
 465             ty::ReLateBound(..)
 466             | ty::ReFree(..)
 467             | ty::ReVar(..)
 468             | ty::RePlaceholder(..)
 469             | ty::ReEmpty(_)
 470             | ty::ReErased => {
 471                 debug!("cannot clean region {:?}", self);
 472                 None
 473             }
 474         }
 475     }
 476 }
 477
 478 impl Clean<WherePredicate> for hir::WherePredicate<'_> {
 479     fn clean(&self, cx: &DocContext<'_>) -> WherePredicate {
 480         match *self {
 481             hir::WherePredicate::BoundPredicate(ref wbp) => WherePredicate::BoundPredicate {
 482                 ty: wbp.bounded_ty.clean(cx),
 483                 bounds: wbp.bounds.clean(cx),
 484             },
 485
 486             hir::WherePredicate::RegionPredicate(ref wrp) => WherePredicate::RegionPredicate {
 487                 lifetime: wrp.lifetime.clean(cx),
 488                 bounds: wrp.bounds.clean(cx),
 489             },
 490
 491             hir::WherePredicate::EqPredicate(ref wrp) => {
 492                 WherePredicate::EqPredicate { lhs: wrp.lhs_ty.clean(cx), rhs: wrp.rhs_ty.clean(cx) }
 493             }
 494         }
 495     }
 496 }
 497
 498 impl<'a> Clean<Option<WherePredicate>> for ty::Predicate<'a> {
 499     fn clean(&self, cx: &DocContext<'_>) -> Option<WherePredicate> {
 500         match self.skip_binders() {
 501             ty::PredicateAtom::Trait(pred, _) => Some(ty::Binder::bind(pred).clean(cx)),
 502             ty::PredicateAtom::RegionOutlives(pred) => pred.clean(cx),
 503             ty::PredicateAtom::TypeOutlives(pred) => pred.clean(cx),
 504             ty::PredicateAtom::Projection(pred) => Some(pred.clean(cx)),
 505
 506             ty::PredicateAtom::Subtype(..)
 507             | ty::PredicateAtom::WellFormed(..)
 508             | ty::PredicateAtom::ObjectSafe(..)
 509             | ty::PredicateAtom::ClosureKind(..)
 510             | ty::PredicateAtom::ConstEvaluatable(..)
 511             | ty::PredicateAtom::ConstEquate(..)
 512             | ty::PredicateAtom::TypeWellFormedFromEnv(..) => panic!("not user writable"),
 513         }
 514     }
 515 }
 516
 517 impl<'a> Clean<WherePredicate> for ty::PolyTraitPredicate<'a> {
 518     fn clean(&self, cx: &DocContext<'_>) -> WherePredicate {
 519         let poly_trait_ref = self.map_bound(|pred| pred.trait_ref);
 520         WherePredicate::BoundPredicate {
 521             ty: poly_trait_ref.skip_binder().self_ty().clean(cx),
 522             bounds: vec![poly_trait_ref.clean(cx)],
 523         }
 524     }
 525 }
 526
 527 impl<'tcx> Clean<Option<WherePredicate>>
 528     for ty::OutlivesPredicate<ty::Region<'tcx>, ty::Region<'tcx>>
 529 {
 530     fn clean(&self, cx: &DocContext<'_>) -> Option<WherePredicate> {
 531         let ty::OutlivesPredicate(a, b) = self;
 532
 533         if let (ty::ReEmpty(_), ty::ReEmpty(_)) = (a, b) {
 534             return None;
 535         }
 536
 537         Some(WherePredicate::RegionPredicate {
 538             lifetime: a.clean(cx).expect("failed to clean lifetime"),
 539             bounds: vec![GenericBound::Outlives(b.clean(cx).expect("failed to clean bounds"))],
 540         })
 541     }
 542 }
 543
 544 impl<'tcx> Clean<Option<WherePredicate>> for ty::OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>> {
 545     fn clean(&self, cx: &DocContext<'_>) -> Option<WherePredicate> {
 546         let ty::OutlivesPredicate(ty, lt) = self;
 547
 548         if let ty::ReEmpty(_) = lt {
 549             return None;
 550         }
 551
 552         Some(WherePredicate::BoundPredicate {
 553             ty: ty.clean(cx),
 554             bounds: vec![GenericBound::Outlives(lt.clean(cx).expect("failed to clean lifetimes"))],
 555         })
 556     }
 557 }
 558
 559 impl<'tcx> Clean<WherePredicate> for ty::ProjectionPredicate<'tcx> {
 560     fn clean(&self, cx: &DocContext<'_>) -> WherePredicate {
 561         let ty::ProjectionPredicate { projection_ty, ty } = self;
 562         WherePredicate::EqPredicate { lhs: projection_ty.clean(cx), rhs: ty.clean(cx) }
 563     }
 564 }
 565
 566 impl<'tcx> Clean<Type> for ty::ProjectionTy<'tcx> {
 567     fn clean(&self, cx: &DocContext<'_>) -> Type {
 568         let lifted = self.lift_to_tcx(cx.tcx).unwrap();
 569         let trait_ = match lifted.trait_ref(cx.tcx).clean(cx) {
 570             GenericBound::TraitBound(t, _) => t.trait_,
 571             GenericBound::Outlives(_) => panic!("cleaning a trait got a lifetime"),
 572         };
 573         Type::QPath {
 574             name: cx.tcx.associated_item(self.item_def_id).ident.name.clean(cx),
 575             self_type: box self.self_ty().clean(cx),
 576             trait_: box trait_,
 577         }
 578     }
 579 }
 580
 581 impl Clean<GenericParamDef> for ty::GenericParamDef {
 582     fn clean(&self, cx: &DocContext<'_>) -> GenericParamDef {
 583         let (name, kind) = match self.kind {
 584             ty::GenericParamDefKind::Lifetime => {
 585                 (self.name.to_string(), GenericParamDefKind::Lifetime)
 586             }
 587             ty::GenericParamDefKind::Type { has_default, synthetic, .. } => {
 588                 let default =
 589                     if has_default { Some(cx.tcx.type_of(self.def_id).clean(cx)) } else { None };
 590                 (
 591                     self.name.clean(cx),
 592                     GenericParamDefKind::Type {
 593                         did: self.def_id,
 594                         bounds: vec![], // These are filled in from the where-clauses.
 595                         default,
 596                         synthetic,
 597                     },
 598                 )
 599             }
 600             ty::GenericParamDefKind::Const { .. } => (
 601                 self.name.clean(cx),
 602                 GenericParamDefKind::Const {
 603                     did: self.def_id,
 604                     ty: cx.tcx.type_of(self.def_id).clean(cx),
 605                 },
 606             ),
 607         };
 608
 609         GenericParamDef { name, kind }
 610     }
 611 }
 612
 613 impl Clean<GenericParamDef> for hir::GenericParam<'_> {
 614     fn clean(&self, cx: &DocContext<'_>) -> GenericParamDef {
 615         let (name, kind) = match self.kind {
 616             hir::GenericParamKind::Lifetime { .. } => {
 617                 let name = if !self.bounds.is_empty() {
 618                     let mut bounds = self.bounds.iter().map(|bound| match bound {
 619                         hir::GenericBound::Outlives(lt) => lt,
 620                         _ => panic!(),
 621                     });
 622                     let name = bounds.next().expect("no more bounds").name.ident();
 623                     let mut s = format!("{}: {}", self.name.ident(), name);
 624                     for bound in bounds {
 625                         s.push_str(&format!(" + {}", bound.name.ident()));
 626                     }
 627                     s
 628                 } else {
 629                     self.name.ident().to_string()
 630                 };
 631                 (name, GenericParamDefKind::Lifetime)
 632             }
 633             hir::GenericParamKind::Type { ref default, synthetic } => (
 634                 self.name.ident().name.clean(cx),
 635                 GenericParamDefKind::Type {
 636                     did: cx.tcx.hir().local_def_id(self.hir_id).to_def_id(),
 637                     bounds: self.bounds.clean(cx),
 638                     default: default.clean(cx),
 639                     synthetic,
 640                 },
 641             ),
 642             hir::GenericParamKind::Const { ref ty } => (
 643                 self.name.ident().name.clean(cx),
 644                 GenericParamDefKind::Const {
 645                     did: cx.tcx.hir().local_def_id(self.hir_id).to_def_id(),
 646                     ty: ty.clean(cx),
 647                 },
 648             ),
 649         };
 650
 651         GenericParamDef { name, kind }
 652     }
 653 }
 654
 655 impl Clean<Generics> for hir::Generics<'_> {
 656     fn clean(&self, cx: &DocContext<'_>) -> Generics {
 657         // Synthetic type-parameters are inserted after normal ones.
 658         // In order for normal parameters to be able to refer to synthetic ones,
 659         // scans them first.
 660         fn is_impl_trait(param: &hir::GenericParam<'_>) -> bool {
 661             match param.kind {
 662                 hir::GenericParamKind::Type { synthetic, .. } => {
 663                     synthetic == Some(hir::SyntheticTyParamKind::ImplTrait)
 664                 }
 665                 _ => false,
 666             }
 667         }
 668         let impl_trait_params = self
 669             .params
 670             .iter()
 671             .filter(|param| is_impl_trait(param))
 672             .map(|param| {
 673                 let param: GenericParamDef = param.clean(cx);
 674                 match param.kind {
 675                     GenericParamDefKind::Lifetime => unreachable!(),
 676                     GenericParamDefKind::Type { did, ref bounds, .. } => {
 677                         cx.impl_trait_bounds.borrow_mut().insert(did.into(), bounds.clone());
 678                     }
 679                     GenericParamDefKind::Const { .. } => unreachable!(),
 680                 }
 681                 param
 682             })
 683             .collect::<Vec<_>>();
 684
 685         let mut params = Vec::with_capacity(self.params.len());
 686         for p in self.params.iter().filter(|p| !is_impl_trait(p)) {
 687             let p = p.clean(cx);
 688             params.push(p);
 689         }
 690         params.extend(impl_trait_params);
 691
 692         let mut generics =
 693             Generics { params, where_predicates: self.where_clause.predicates.clean(cx) };
 694
 695         // Some duplicates are generated for ?Sized bounds between type params and where
 696         // predicates. The point in here is to move the bounds definitions from type params
 697         // to where predicates when such cases occur.
 698         for where_pred in &mut generics.where_predicates {
 699             match *where_pred {
 700                 WherePredicate::BoundPredicate { ty: Generic(ref name), ref mut bounds } => {
 701                     if bounds.is_empty() {
 702                         for param in &mut generics.params {
 703                             match param.kind {
 704                                 GenericParamDefKind::Lifetime => {}
 705                                 GenericParamDefKind::Type { bounds: ref mut ty_bounds, .. } => {
 706                                     if &param.name == name {
 707                                         mem::swap(bounds, ty_bounds);
 708                                         break;
 709                                     }
 710                                 }
 711                                 GenericParamDefKind::Const { .. } => {}
 712                             }
 713                         }
 714                     }
 715                 }
 716                 _ => continue,
 717             }
 718         }
 719         generics
 720     }
 721 }
 722
 723 impl<'a, 'tcx> Clean<Generics> for (&'a ty::Generics, ty::GenericPredicates<'tcx>) {
 724     fn clean(&self, cx: &DocContext<'_>) -> Generics {
 725         use self::WherePredicate as WP;
 726         use std::collections::BTreeMap;
 727
 728         let (gens, preds) = *self;
 729
 730         // Don't populate `cx.impl_trait_bounds` before `clean`ning `where` clauses,
 731         // since `Clean for ty::Predicate` would consume them.
 732         let mut impl_trait = BTreeMap::<ImplTraitParam, Vec<GenericBound>>::default();
 733
 734         // Bounds in the type_params and lifetimes fields are repeated in the
 735         // predicates field (see rustc_typeck::collect::ty_generics), so remove
 736         // them.
 737         let stripped_params = gens
 738             .params
 739             .iter()
 740             .filter_map(|param| match param.kind {
 741                 ty::GenericParamDefKind::Lifetime => Some(param.clean(cx)),
 742                 ty::GenericParamDefKind::Type { synthetic, .. } => {
 743                     if param.name == kw::SelfUpper {
 744                         assert_eq!(param.index, 0);
 745                         return None;
 746                     }
 747                     if synthetic == Some(hir::SyntheticTyParamKind::ImplTrait) {
 748                         impl_trait.insert(param.index.into(), vec![]);
 749                         return None;
 750                     }
 751                     Some(param.clean(cx))
 752                 }
 753                 ty::GenericParamDefKind::Const { .. } => Some(param.clean(cx)),
 754             })
 755             .collect::<Vec<GenericParamDef>>();
 756
 757         // param index -> [(DefId of trait, associated type name, type)]
 758         let mut impl_trait_proj = FxHashMap::<u32, Vec<(DefId, String, Ty<'tcx>)>>::default();
 759
 760         let where_predicates = preds
 761             .predicates
 762             .iter()
 763             .flat_map(|(p, _)| {
 764                 let mut projection = None;
 765                 let param_idx = (|| {
 766                     match p.skip_binders() {
 767                         ty::PredicateAtom::Trait(pred, _constness) => {
 768                             if let ty::Param(param) = pred.self_ty().kind() {
 769                                 return Some(param.index);
 770                             }
 771                         }
 772                         ty::PredicateAtom::TypeOutlives(ty::OutlivesPredicate(ty, _reg)) => {
 773                             if let ty::Param(param) = ty.kind() {
 774                                 return Some(param.index);
 775                             }
 776                         }
 777                         ty::PredicateAtom::Projection(p) => {
 778                             if let ty::Param(param) = p.projection_ty.self_ty().kind() {
 779                                 projection = Some(ty::Binder::bind(p));
 780                                 return Some(param.index);
 781                             }
 782                         }
 783                         _ => (),
 784                     }
 785
 786                     None
 787                 })();
 788
 789                 if let Some(param_idx) = param_idx {
 790                     if let Some(b) = impl_trait.get_mut(&param_idx.into()) {
 791                         let p = p.clean(cx)?;
 792
 793                         b.extend(
 794                             p.get_bounds()
 795                                 .into_iter()
 796                                 .flatten()
 797                                 .cloned()
 798                                 .filter(|b| !b.is_sized_bound(cx)),
 799                         );
 800
 801                         let proj = projection
 802                             .map(|p| (p.skip_binder().projection_ty.clean(cx), p.skip_binder().ty));
 803                         if let Some(((_, trait_did, name), rhs)) =
 804                             proj.as_ref().and_then(|(lhs, rhs)| Some((lhs.projection()?, rhs)))
 805                         {
 806                             impl_trait_proj.entry(param_idx).or_default().push((
 807                                 trait_did,
 808                                 name.to_string(),
 809                                 rhs,
 810                             ));
 811                         }
 812
 813                         return None;
 814                     }
 815                 }
 816
 817                 Some(p)
 818             })
 819             .collect::<Vec<_>>();
 820
 821         for (param, mut bounds) in impl_trait {
 822             // Move trait bounds to the front.
 823             bounds.sort_by_key(|b| if let GenericBound::TraitBound(..) = b { false } else { true });
 824
 825             if let crate::core::ImplTraitParam::ParamIndex(idx) = param {
 826                 if let Some(proj) = impl_trait_proj.remove(&idx) {
 827                     for (trait_did, name, rhs) in proj {
 828                         simplify::merge_bounds(cx, &mut bounds, trait_did, &name, &rhs.clean(cx));
 829                     }
 830                 }
 831             } else {
 832                 unreachable!();
 833             }
 834
 835             cx.impl_trait_bounds.borrow_mut().insert(param, bounds);
 836         }
 837
 838         // Now that `cx.impl_trait_bounds` is populated, we can process
 839         // remaining predicates which could contain `impl Trait`.
 840         let mut where_predicates =
 841             where_predicates.into_iter().flat_map(|p| p.clean(cx)).collect::<Vec<_>>();
 842
 843         // Type parameters and have a Sized bound by default unless removed with
 844         // ?Sized. Scan through the predicates and mark any type parameter with
 845         // a Sized bound, removing the bounds as we find them.
 846         //
 847         // Note that associated types also have a sized bound by default, but we
 848         // don't actually know the set of associated types right here so that's
 849         // handled in cleaning associated types
 850         let mut sized_params = FxHashSet::default();
 851         where_predicates.retain(|pred| match *pred {
 852             WP::BoundPredicate { ty: Generic(ref g), ref bounds } => {
 853                 if bounds.iter().any(|b| b.is_sized_bound(cx)) {
 854                     sized_params.insert(g.clone());
 855                     false
 856                 } else {
 857                     true
 858                 }
 859             }
 860             _ => true,
 861         });
 862
 863         // Run through the type parameters again and insert a ?Sized
 864         // unbound for any we didn't find to be Sized.
 865         for tp in &stripped_params {
 866             if matches!(tp.kind, types::GenericParamDefKind::Type { .. })
 867                 && !sized_params.contains(&tp.name)
 868             {
 869                 where_predicates.push(WP::BoundPredicate {
 870                     ty: Type::Generic(tp.name.clone()),
 871                     bounds: vec![GenericBound::maybe_sized(cx)],
 872                 })
 873             }
 874         }
 875
 876         // It would be nice to collect all of the bounds on a type and recombine
 877         // them if possible, to avoid e.g., `where T: Foo, T: Bar, T: Sized, T: 'a`
 878         // and instead see `where T: Foo + Bar + Sized + 'a`
 879
 880         Generics {
 881             params: stripped_params,
 882             where_predicates: simplify::where_clauses(cx, where_predicates),
 883         }
 884     }
 885 }
 886
 887 impl<'a> Clean<Method>
 888     for (&'a hir::FnSig<'a>, &'a hir::Generics<'a>, hir::BodyId, Option<hir::Defaultness>)
 889 {
 890     fn clean(&self, cx: &DocContext<'_>) -> Method {
 891         let (generics, decl) =
 892             enter_impl_trait(cx, || (self.1.clean(cx), (&*self.0.decl, self.2).clean(cx)));
 893         let (all_types, ret_types) = get_all_types(&generics, &decl, cx);
 894         Method { decl, generics, header: self.0.header, defaultness: self.3, all_types, ret_types }
 895     }
 896 }
 897
 898 impl Clean<Item> for doctree::Function<'_> {
 899     fn clean(&self, cx: &DocContext<'_>) -> Item {
 900         let (generics, decl) =
 901             enter_impl_trait(cx, || (self.generics.clean(cx), (self.decl, self.body).clean(cx)));
 902
 903         let did = cx.tcx.hir().local_def_id(self.id);
 904         let constness = if is_const_fn(cx.tcx, did.to_def_id())
 905             && !is_unstable_const_fn(cx.tcx, did.to_def_id()).is_some()
 906         {
 907             hir::Constness::Const
 908         } else {
 909             hir::Constness::NotConst
 910         };
 911         let (all_types, ret_types) = get_all_types(&generics, &decl, cx);
 912         Item {
 913             name: Some(self.name.clean(cx)),
 914             attrs: self.attrs.clean(cx),
 915             source: self.whence.clean(cx),
 916             visibility: self.vis.clean(cx),
 917             stability: cx.stability(self.id).clean(cx),
 918             deprecation: cx.deprecation(self.id).clean(cx),
 919             def_id: did.to_def_id(),
 920             inner: FunctionItem(Function {
 921                 decl,
 922                 generics,
 923                 header: hir::FnHeader { constness, ..self.header },
 924                 all_types,
 925                 ret_types,
 926             }),
 927         }
 928     }
 929 }
 930
 931 impl<'a> Clean<Arguments> for (&'a [hir::Ty<'a>], &'a [Ident]) {
 932     fn clean(&self, cx: &DocContext<'_>) -> Arguments {
 933         Arguments {
 934             values: self
 935                 .0
 936                 .iter()
 937                 .enumerate()
 938                 .map(|(i, ty)| {
 939                     let mut name =
 940                         self.1.get(i).map(|ident| ident.to_string()).unwrap_or(String::new());
 941                     if name.is_empty() {
 942                         name = "_".to_string();
 943                     }
 944                     Argument { name, type_: ty.clean(cx) }
 945                 })
 946                 .collect(),
 947         }
 948     }
 949 }
 950
 951 impl<'a> Clean<Arguments> for (&'a [hir::Ty<'a>], hir::BodyId) {
 952     fn clean(&self, cx: &DocContext<'_>) -> Arguments {
 953         let body = cx.tcx.hir().body(self.1);
 954
 955         Arguments {
 956             values: self
 957                 .0
 958                 .iter()
 959                 .enumerate()
 960                 .map(|(i, ty)| Argument {
 961                     name: name_from_pat(&body.params[i].pat),
 962                     type_: ty.clean(cx),
 963                 })
 964                 .collect(),
 965         }
 966     }
 967 }
 968
 969 impl<'a, A: Copy> Clean<FnDecl> for (&'a hir::FnDecl<'a>, A)
 970 where
 971     (&'a [hir::Ty<'a>], A): Clean<Arguments>,
 972 {
 973     fn clean(&self, cx: &DocContext<'_>) -> FnDecl {
 974         FnDecl {
 975             inputs: (&self.0.inputs[..], self.1).clean(cx),
 976             output: self.0.output.clean(cx),
 977             c_variadic: self.0.c_variadic,
 978             attrs: Attributes::default(),
 979         }
 980     }
 981 }
 982
 983 impl<'tcx> Clean<FnDecl> for (DefId, ty::PolyFnSig<'tcx>) {
 984     fn clean(&self, cx: &DocContext<'_>) -> FnDecl {
 985         let (did, sig) = *self;
 986         let mut names = if did.is_local() { &[] } else { cx.tcx.fn_arg_names(did) }.iter();
 987
 988         FnDecl {
 989             output: Return(sig.skip_binder().output().clean(cx)),
 990             attrs: Attributes::default(),
 991             c_variadic: sig.skip_binder().c_variadic,
 992             inputs: Arguments {
 993                 values: sig
 994                     .skip_binder()
 995                     .inputs()
 996                     .iter()
 997                     .map(|t| Argument {
 998                         type_: t.clean(cx),
 999                         name: names.next().map_or(String::new(), |name| name.to_string()),
1000                     })
1001                     .collect(),
1002             },
1003         }
1004     }
1005 }
1006
1007 impl Clean<FnRetTy> for hir::FnRetTy<'_> {
1008     fn clean(&self, cx: &DocContext<'_>) -> FnRetTy {
1009         match *self {
1010             Self::Return(ref typ) => Return(typ.clean(cx)),
1011             Self::DefaultReturn(..) => DefaultReturn,
1012         }
1013     }
1014 }
1015
1016 impl Clean<Item> for doctree::Trait<'_> {
1017     fn clean(&self, cx: &DocContext<'_>) -> Item {
1018         let attrs = self.attrs.clean(cx);
1019         let is_spotlight = attrs.has_doc_flag(sym::spotlight);
1020         Item {
1021             name: Some(self.name.clean(cx)),
1022             attrs,
1023             source: self.whence.clean(cx),
1024             def_id: cx.tcx.hir().local_def_id(self.id).to_def_id(),
1025             visibility: self.vis.clean(cx),
1026             stability: cx.stability(self.id).clean(cx),
1027             deprecation: cx.deprecation(self.id).clean(cx),
1028             inner: TraitItem(Trait {
1029                 auto: self.is_auto.clean(cx),
1030                 unsafety: self.unsafety,
1031                 items: self.items.iter().map(|ti| ti.clean(cx)).collect(),
1032                 generics: self.generics.clean(cx),
1033                 bounds: self.bounds.clean(cx),
1034                 is_spotlight,
1035                 is_auto: self.is_auto.clean(cx),
1036             }),
1037         }
1038     }
1039 }
1040
1041 impl Clean<Item> for doctree::TraitAlias<'_> {
1042     fn clean(&self, cx: &DocContext<'_>) -> Item {
1043         let attrs = self.attrs.clean(cx);
1044         Item {
1045             name: Some(self.name.clean(cx)),
1046             attrs,
1047             source: self.whence.clean(cx),
1048             def_id: cx.tcx.hir().local_def_id(self.id).to_def_id(),
1049             visibility: self.vis.clean(cx),
1050             stability: cx.stability(self.id).clean(cx),
1051             deprecation: cx.deprecation(self.id).clean(cx),
1052             inner: TraitAliasItem(TraitAlias {
1053                 generics: self.generics.clean(cx),
1054                 bounds: self.bounds.clean(cx),
1055             }),
1056         }
1057     }
1058 }
1059
1060 impl Clean<bool> for hir::IsAuto {
1061     fn clean(&self, _: &DocContext<'_>) -> bool {
1062         match *self {
1063             hir::IsAuto::Yes => true,
1064             hir::IsAuto::No => false,
1065         }
1066     }
1067 }
1068
1069 impl Clean<Type> for hir::TraitRef<'_> {
1070     fn clean(&self, cx: &DocContext<'_>) -> Type {
1071         resolve_type(cx, self.path.clean(cx), self.hir_ref_id)
1072     }
1073 }
1074
1075 impl Clean<PolyTrait> for hir::PolyTraitRef<'_> {
1076     fn clean(&self, cx: &DocContext<'_>) -> PolyTrait {
1077         PolyTrait {
1078             trait_: self.trait_ref.clean(cx),
1079             generic_params: self.bound_generic_params.clean(cx),
1080         }
1081     }
1082 }
1083
1084 impl Clean<TypeKind> for hir::def::DefKind {
1085     fn clean(&self, _: &DocContext<'_>) -> TypeKind {
1086         match *self {
1087             hir::def::DefKind::Mod => TypeKind::Module,
1088             hir::def::DefKind::Struct => TypeKind::Struct,
1089             hir::def::DefKind::Union => TypeKind::Union,
1090             hir::def::DefKind::Enum => TypeKind::Enum,
1091             hir::def::DefKind::Trait => TypeKind::Trait,
1092             hir::def::DefKind::TyAlias => TypeKind::Typedef,
1093             hir::def::DefKind::ForeignTy => TypeKind::Foreign,
1094             hir::def::DefKind::TraitAlias => TypeKind::TraitAlias,
1095             hir::def::DefKind::Fn => TypeKind::Function,
1096             hir::def::DefKind::Const => TypeKind::Const,
1097             hir::def::DefKind::Static => TypeKind::Static,
1098             hir::def::DefKind::Macro(_) => TypeKind::Macro,
1099             _ => TypeKind::Foreign,
1100         }
1101     }
1102 }
1103
1104 impl Clean<Item> for hir::TraitItem<'_> {
1105     fn clean(&self, cx: &DocContext<'_>) -> Item {
1106         let local_did = cx.tcx.hir().local_def_id(self.hir_id);
1107         let inner = match self.kind {
1108             hir::TraitItemKind::Const(ref ty, default) => {
1109                 AssocConstItem(ty.clean(cx), default.map(|e| print_const_expr(cx, e)))
1110             }
1111             hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Provided(body)) => {
1112                 let mut m = (sig, &self.generics, body, None).clean(cx);
1113                 if m.header.constness == hir::Constness::Const
1114                     && is_unstable_const_fn(cx.tcx, local_did.to_def_id()).is_some()
1115                 {
1116                     m.header.constness = hir::Constness::NotConst;
1117                 }
1118                 MethodItem(m)
1119             }
1120             hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Required(ref names)) => {
1121                 let (generics, decl) = enter_impl_trait(cx, || {
1122                     (self.generics.clean(cx), (&*sig.decl, &names[..]).clean(cx))
1123                 });
1124                 let (all_types, ret_types) = get_all_types(&generics, &decl, cx);
1125                 let mut t = TyMethod { header: sig.header, decl, generics, all_types, ret_types };
1126                 if t.header.constness == hir::Constness::Const
1127                     && is_unstable_const_fn(cx.tcx, local_did.to_def_id()).is_some()
1128                 {
1129                     t.header.constness = hir::Constness::NotConst;
1130                 }
1131                 TyMethodItem(t)
1132             }
1133             hir::TraitItemKind::Type(ref bounds, ref default) => {
1134                 AssocTypeItem(bounds.clean(cx), default.clean(cx))
1135             }
1136         };
1137         Item {
1138             name: Some(self.ident.name.clean(cx)),
1139             attrs: self.attrs.clean(cx),
1140             source: self.span.clean(cx),
1141             def_id: local_did.to_def_id(),
1142             visibility: Visibility::Inherited,
1143             stability: get_stability(cx, local_did.to_def_id()),
1144             deprecation: get_deprecation(cx, local_did.to_def_id()),
1145             inner,
1146         }
1147     }
1148 }
1149
1150 impl Clean<Item> for hir::ImplItem<'_> {
1151     fn clean(&self, cx: &DocContext<'_>) -> Item {
1152         let local_did = cx.tcx.hir().local_def_id(self.hir_id);
1153         let inner = match self.kind {
1154             hir::ImplItemKind::Const(ref ty, expr) => {
1155                 AssocConstItem(ty.clean(cx), Some(print_const_expr(cx, expr)))
1156             }
1157             hir::ImplItemKind::Fn(ref sig, body) => {
1158                 let mut m = (sig, &self.generics, body, Some(self.defaultness)).clean(cx);
1159                 if m.header.constness == hir::Constness::Const
1160                     && is_unstable_const_fn(cx.tcx, local_did.to_def_id()).is_some()
1161                 {
1162                     m.header.constness = hir::Constness::NotConst;
1163                 }
1164                 MethodItem(m)
1165             }
1166             hir::ImplItemKind::TyAlias(ref ty) => {
1167                 let type_ = ty.clean(cx);
1168                 let item_type = type_.def_id().and_then(|did| inline::build_ty(cx, did));
1169                 TypedefItem(Typedef { type_, generics: Generics::default(), item_type }, true)
1170             }
1171         };
1172         Item {
1173             name: Some(self.ident.name.clean(cx)),
1174             source: self.span.clean(cx),
1175             attrs: self.attrs.clean(cx),
1176             def_id: local_did.to_def_id(),
1177             visibility: self.vis.clean(cx),
1178             stability: get_stability(cx, local_did.to_def_id()),
1179             deprecation: get_deprecation(cx, local_did.to_def_id()),
1180             inner,
1181         }
1182     }
1183 }
1184
1185 impl Clean<Item> for ty::AssocItem {
1186     fn clean(&self, cx: &DocContext<'_>) -> Item {
1187         let inner = match self.kind {
1188             ty::AssocKind::Const => {
1189                 let ty = cx.tcx.type_of(self.def_id);
1190                 let default = if self.defaultness.has_value() {
1191                     Some(inline::print_inlined_const(cx, self.def_id))
1192                 } else {
1193                     None
1194                 };
1195                 AssocConstItem(ty.clean(cx), default)
1196             }
1197             ty::AssocKind::Fn => {
1198                 let generics =
1199                     (cx.tcx.generics_of(self.def_id), cx.tcx.explicit_predicates_of(self.def_id))
1200                         .clean(cx);
1201                 let sig = cx.tcx.fn_sig(self.def_id);
1202                 let mut decl = (self.def_id, sig).clean(cx);
1203
1204                 if self.fn_has_self_parameter {
1205                     let self_ty = match self.container {
1206                         ty::ImplContainer(def_id) => cx.tcx.type_of(def_id),
1207                         ty::TraitContainer(_) => cx.tcx.types.self_param,
1208                     };
1209                     let self_arg_ty = sig.input(0).skip_binder();
1210                     if self_arg_ty == self_ty {
1211                         decl.inputs.values[0].type_ = Generic(String::from("Self"));
1212                     } else if let ty::Ref(_, ty, _) = *self_arg_ty.kind() {
1213                         if ty == self_ty {
1214                             match decl.inputs.values[0].type_ {
1215                                 BorrowedRef { ref mut type_, .. } => {
1216                                     **type_ = Generic(String::from("Self"))
1217                                 }
1218                                 _ => unreachable!(),
1219                             }
1220                         }
1221                     }
1222                 }
1223
1224                 let provided = match self.container {
1225                     ty::ImplContainer(_) => true,
1226                     ty::TraitContainer(_) => self.defaultness.has_value(),
1227                 };
1228                 let (all_types, ret_types) = get_all_types(&generics, &decl, cx);
1229                 if provided {
1230                     let constness = if is_min_const_fn(cx.tcx, self.def_id) {
1231                         hir::Constness::Const
1232                     } else {
1233                         hir::Constness::NotConst
1234                     };
1235                     let asyncness = cx.tcx.asyncness(self.def_id);
1236                     let defaultness = match self.container {
1237                         ty::ImplContainer(_) => Some(self.defaultness),
1238                         ty::TraitContainer(_) => None,
1239                     };
1240                     MethodItem(Method {
1241                         generics,
1242                         decl,
1243                         header: hir::FnHeader {
1244                             unsafety: sig.unsafety(),
1245                             abi: sig.abi(),
1246                             constness,
1247                             asyncness,
1248                         },
1249                         defaultness,
1250                         all_types,
1251                         ret_types,
1252                     })
1253                 } else {
1254                     TyMethodItem(TyMethod {
1255                         generics,
1256                         decl,
1257                         header: hir::FnHeader {
1258                             unsafety: sig.unsafety(),
1259                             abi: sig.abi(),
1260                             constness: hir::Constness::NotConst,
1261                             asyncness: hir::IsAsync::NotAsync,
1262                         },
1263                         all_types,
1264                         ret_types,
1265                     })
1266                 }
1267             }
1268             ty::AssocKind::Type => {
1269                 let my_name = self.ident.name.clean(cx);
1270
1271                 if let ty::TraitContainer(did) = self.container {
1272                     // When loading a cross-crate associated type, the bounds for this type
1273                     // are actually located on the trait/impl itself, so we need to load
1274                     // all of the generics from there and then look for bounds that are
1275                     // applied to this associated type in question.
1276                     let predicates = cx.tcx.explicit_predicates_of(did);
1277                     let generics = (cx.tcx.generics_of(did), predicates).clean(cx);
1278                     let mut bounds = generics
1279                         .where_predicates
1280                         .iter()
1281                         .filter_map(|pred| {
1282                             let (name, self_type, trait_, bounds) = match *pred {
1283                                 WherePredicate::BoundPredicate {
1284                                     ty: QPath { ref name, ref self_type, ref trait_ },
1285                                     ref bounds,
1286                                 } => (name, self_type, trait_, bounds),
1287                                 _ => return None,
1288                             };
1289                             if *name != my_name {
1290                                 return None;
1291                             }
1292                             match **trait_ {
1293                                 ResolvedPath { did, .. } if did == self.container.id() => {}
1294                                 _ => return None,
1295                             }
1296                             match **self_type {
1297                                 Generic(ref s) if *s == "Self" => {}
1298                                 _ => return None,
1299                             }
1300                             Some(bounds)
1301                         })
1302                         .flat_map(|i| i.iter().cloned())
1303                         .collect::<Vec<_>>();
1304                     // Our Sized/?Sized bound didn't get handled when creating the generics
1305                     // because we didn't actually get our whole set of bounds until just now
1306                     // (some of them may have come from the trait). If we do have a sized
1307                     // bound, we remove it, and if we don't then we add the `?Sized` bound
1308                     // at the end.
1309                     match bounds.iter().position(|b| b.is_sized_bound(cx)) {
1310                         Some(i) => {
1311                             bounds.remove(i);
1312                         }
1313                         None => bounds.push(GenericBound::maybe_sized(cx)),
1314                     }
1315
1316                     let ty = if self.defaultness.has_value() {
1317                         Some(cx.tcx.type_of(self.def_id))
1318                     } else {
1319                         None
1320                     };
1321
1322                     AssocTypeItem(bounds, ty.clean(cx))
1323                 } else {
1324                     let type_ = cx.tcx.type_of(self.def_id).clean(cx);
1325                     let item_type = type_.def_id().and_then(|did| inline::build_ty(cx, did));
1326                     TypedefItem(
1327                         Typedef {
1328                             type_,
1329                             generics: Generics { params: Vec::new(), where_predicates: Vec::new() },
1330                             item_type,
1331                         },
1332                         true,
1333                     )
1334                 }
1335             }
1336         };
1337
1338         let visibility = match self.container {
1339             ty::ImplContainer(_) => self.vis.clean(cx),
1340             ty::TraitContainer(_) => Inherited,
1341         };
1342
1343         Item {
1344             name: Some(self.ident.name.clean(cx)),
1345             visibility,
1346             stability: get_stability(cx, self.def_id),
1347             deprecation: get_deprecation(cx, self.def_id),
1348             def_id: self.def_id,
1349             attrs: inline::load_attrs(cx, self.def_id).clean(cx),
1350             source: cx.tcx.def_span(self.def_id).clean(cx),
1351             inner,
1352         }
1353     }
1354 }
1355
1356 impl Clean<Type> for hir::Ty<'_> {
1357     fn clean(&self, cx: &DocContext<'_>) -> Type {
1358         use rustc_hir::*;
1359
1360         match self.kind {
1361             TyKind::Never => Never,
1362             TyKind::Ptr(ref m) => RawPointer(m.mutbl, box m.ty.clean(cx)),
1363             TyKind::Rptr(ref l, ref m) => {
1364                 let lifetime = if l.is_elided() { None } else { Some(l.clean(cx)) };
1365                 BorrowedRef { lifetime, mutability: m.mutbl, type_: box m.ty.clean(cx) }
1366             }
1367             TyKind::Slice(ref ty) => Slice(box ty.clean(cx)),
1368             TyKind::Array(ref ty, ref length) => {
1369                 let def_id = cx.tcx.hir().local_def_id(length.hir_id);
1370                 // NOTE(min_const_generics): We can't use `const_eval_poly` for constants
1371                 // as we currently do not supply the parent generics to anonymous constants
1372                 // but do allow `ConstKind::Param`.
1373                 //
1374                 // `const_eval_poly` tries to to first substitute generic parameters which
1375                 // results in an ICE while manually constructing the constant and using `eval`
1376                 // does nothing for `ConstKind::Param`.
1377                 let ct = ty::Const::from_anon_const(cx.tcx, def_id);
1378                 let param_env = cx.tcx.param_env(def_id);
1379                 let length = print_const(cx, ct.eval(cx.tcx, param_env));
1380                 Array(box ty.clean(cx), length)
1381             }
1382             TyKind::Tup(ref tys) => Tuple(tys.clean(cx)),
1383             TyKind::OpaqueDef(item_id, _) => {
1384                 let item = cx.tcx.hir().expect_item(item_id.id);
1385                 if let hir::ItemKind::OpaqueTy(ref ty) = item.kind {
1386                     ImplTrait(ty.bounds.clean(cx))
1387                 } else {
1388                     unreachable!()
1389                 }
1390             }
1391             TyKind::Path(hir::QPath::Resolved(None, ref path)) => {
1392                 if let Res::Def(DefKind::TyParam, did) = path.res {
1393                     if let Some(new_ty) = cx.ty_substs.borrow().get(&did).cloned() {
1394                         return new_ty;
1395                     }
1396                     if let Some(bounds) = cx.impl_trait_bounds.borrow_mut().remove(&did.into()) {
1397                         return ImplTrait(bounds);
1398                     }
1399                 }
1400
1401                 let mut alias = None;
1402                 if let Res::Def(DefKind::TyAlias, def_id) = path.res {
1403                     // Substitute private type aliases
1404                     if let Some(def_id) = def_id.as_local() {
1405                         let hir_id = cx.tcx.hir().local_def_id_to_hir_id(def_id);
1406                         if !cx.renderinfo.borrow().access_levels.is_exported(def_id.to_def_id()) {
1407                             alias = Some(&cx.tcx.hir().expect_item(hir_id).kind);
1408                         }
1409                     }
1410                 };
1411
1412                 if let Some(&hir::ItemKind::TyAlias(ref ty, ref generics)) = alias {
1413                     let provided_params = &path.segments.last().expect("segments were empty");
1414                     let mut ty_substs = FxHashMap::default();
1415                     let mut lt_substs = FxHashMap::default();
1416                     let mut ct_substs = FxHashMap::default();
1417                     let generic_args = provided_params.generic_args();
1418                     {
1419                         let mut indices: GenericParamCount = Default::default();
1420                         for param in generics.params.iter() {
1421                             match param.kind {
1422                                 hir::GenericParamKind::Lifetime { .. } => {
1423                                     let mut j = 0;
1424                                     let lifetime =
1425                                         generic_args.args.iter().find_map(|arg| match arg {
1426                                             hir::GenericArg::Lifetime(lt) => {
1427                                                 if indices.lifetimes == j {
1428                                                     return Some(lt);
1429                                                 }
1430                                                 j += 1;
1431                                                 None
1432                                             }
1433                                             _ => None,
1434                                         });
1435                                     if let Some(lt) = lifetime.cloned() {
1436                                         let lt_def_id = cx.tcx.hir().local_def_id(param.hir_id);
1437                                         let cleaned = if !lt.is_elided() {
1438                                             lt.clean(cx)
1439                                         } else {
1440                                             self::types::Lifetime::elided()
1441                                         };
1442                                         lt_substs.insert(lt_def_id.to_def_id(), cleaned);
1443                                     }
1444                                     indices.lifetimes += 1;
1445                                 }
1446                                 hir::GenericParamKind::Type { ref default, .. } => {
1447                                     let ty_param_def_id = cx.tcx.hir().local_def_id(param.hir_id);
1448                                     let mut j = 0;
1449                                     let type_ =
1450                                         generic_args.args.iter().find_map(|arg| match arg {
1451                                             hir::GenericArg::Type(ty) => {
1452                                                 if indices.types == j {
1453                                                     return Some(ty);
1454                                                 }
1455                                                 j += 1;
1456                                                 None
1457                                             }
1458                                             _ => None,
1459                                         });
1460                                     if let Some(ty) = type_ {
1461                                         ty_substs.insert(ty_param_def_id.to_def_id(), ty.clean(cx));
1462                                     } else if let Some(default) = *default {
1463                                         ty_substs
1464                                             .insert(ty_param_def_id.to_def_id(), default.clean(cx));
1465                                     }
1466                                     indices.types += 1;
1467                                 }
1468                                 hir::GenericParamKind::Const { .. } => {
1469                                     let const_param_def_id =
1470                                         cx.tcx.hir().local_def_id(param.hir_id);
1471                                     let mut j = 0;
1472                                     let const_ =
1473                                         generic_args.args.iter().find_map(|arg| match arg {
1474                                             hir::GenericArg::Const(ct) => {
1475                                                 if indices.consts == j {
1476                                                     return Some(ct);
1477                                                 }
1478                                                 j += 1;
1479                                                 None
1480                                             }
1481                                             _ => None,
1482                                         });
1483                                     if let Some(ct) = const_ {
1484                                         ct_substs
1485                                             .insert(const_param_def_id.to_def_id(), ct.clean(cx));
1486                                     }
1487                                     // FIXME(const_generics:defaults)
1488                                     indices.consts += 1;
1489                                 }
1490                             }
1491                         }
1492                     }
1493                     return cx.enter_alias(ty_substs, lt_substs, ct_substs, || ty.clean(cx));
1494                 }
1495                 resolve_type(cx, path.clean(cx), self.hir_id)
1496             }
1497             TyKind::Path(hir::QPath::Resolved(Some(ref qself), ref p)) => {
1498                 let segments = if p.is_global() { &p.segments[1..] } else { &p.segments };
1499                 let trait_segments = &segments[..segments.len() - 1];
1500                 let trait_path = self::Path {
1501                     global: p.is_global(),
1502                     res: Res::Def(
1503                         DefKind::Trait,
1504                         cx.tcx.associated_item(p.res.def_id()).container.id(),
1505                     ),
1506                     segments: trait_segments.clean(cx),
1507                 };
1508                 Type::QPath {
1509                     name: p.segments.last().expect("segments were empty").ident.name.clean(cx),
1510                     self_type: box qself.clean(cx),
1511                     trait_: box resolve_type(cx, trait_path, self.hir_id),
1512                 }
1513             }
1514             TyKind::Path(hir::QPath::TypeRelative(ref qself, ref segment)) => {
1515                 let mut res = Res::Err;
1516                 let ty = hir_ty_to_ty(cx.tcx, self);
1517                 if let ty::Projection(proj) = ty.kind() {
1518                     res = Res::Def(DefKind::Trait, proj.trait_ref(cx.tcx).def_id);
1519                 }
1520                 let trait_path = hir::Path { span: self.span, res, segments: &[] };
1521                 Type::QPath {
1522                     name: segment.ident.name.clean(cx),
1523                     self_type: box qself.clean(cx),
1524                     trait_: box resolve_type(cx, trait_path.clean(cx), self.hir_id),
1525                 }
1526             }
1527             TyKind::Path(hir::QPath::LangItem(..)) => {
1528                 bug!("clean: requiring documentation of lang item")
1529             }
1530             TyKind::TraitObject(ref bounds, ref lifetime) => {
1531                 match bounds[0].clean(cx).trait_ {
1532                     ResolvedPath { path, param_names: None, did, is_generic } => {
1533                         let mut bounds: Vec<self::GenericBound> = bounds[1..]
1534                             .iter()
1535                             .map(|bound| {
1536                                 self::GenericBound::TraitBound(
1537                                     bound.clean(cx),
1538                                     hir::TraitBoundModifier::None,
1539                                 )
1540                             })
1541                             .collect();
1542                         if !lifetime.is_elided() {
1543                             bounds.push(self::GenericBound::Outlives(lifetime.clean(cx)));
1544                         }
1545                         ResolvedPath { path, param_names: Some(bounds), did, is_generic }
1546                     }
1547                     _ => Infer, // shouldn't happen
1548                 }
1549             }
1550             TyKind::BareFn(ref barefn) => BareFunction(box barefn.clean(cx)),
1551             TyKind::Infer | TyKind::Err => Infer,
1552             TyKind::Typeof(..) => panic!("unimplemented type {:?}", self.kind),
1553         }
1554     }
1555 }
1556
1557 impl<'tcx> Clean<Type> for Ty<'tcx> {
1558     fn clean(&self, cx: &DocContext<'_>) -> Type {
1559         debug!("cleaning type: {:?}", self);
1560         match *self.kind() {
1561             ty::Never => Never,
1562             ty::Bool => Primitive(PrimitiveType::Bool),
1563             ty::Char => Primitive(PrimitiveType::Char),
1564             ty::Int(int_ty) => Primitive(int_ty.into()),
1565             ty::Uint(uint_ty) => Primitive(uint_ty.into()),
1566             ty::Float(float_ty) => Primitive(float_ty.into()),
1567             ty::Str => Primitive(PrimitiveType::Str),
1568             ty::Slice(ty) => Slice(box ty.clean(cx)),
1569             ty::Array(ty, n) => {
1570                 let mut n = cx.tcx.lift(&n).expect("array lift failed");
1571                 n = n.eval(cx.tcx, ty::ParamEnv::reveal_all());
1572                 let n = print_const(cx, n);
1573                 Array(box ty.clean(cx), n)
1574             }
1575             ty::RawPtr(mt) => RawPointer(mt.mutbl, box mt.ty.clean(cx)),
1576             ty::Ref(r, ty, mutbl) => {
1577                 BorrowedRef { lifetime: r.clean(cx), mutability: mutbl, type_: box ty.clean(cx) }
1578             }
1579             ty::FnDef(..) | ty::FnPtr(_) => {
1580                 let ty = cx.tcx.lift(self).expect("FnPtr lift failed");
1581                 let sig = ty.fn_sig(cx.tcx);
1582                 let def_id = DefId::local(CRATE_DEF_INDEX);
1583                 BareFunction(box BareFunctionDecl {
1584                     unsafety: sig.unsafety(),
1585                     generic_params: Vec::new(),
1586                     decl: (def_id, sig).clean(cx),
1587                     abi: sig.abi(),
1588                 })
1589             }
1590             ty::Adt(def, substs) => {
1591                 let did = def.did;
1592                 let kind = match def.adt_kind() {
1593                     AdtKind::Struct => TypeKind::Struct,
1594                     AdtKind::Union => TypeKind::Union,
1595                     AdtKind::Enum => TypeKind::Enum,
1596                 };
1597                 inline::record_extern_fqn(cx, did, kind);
1598                 let path = external_path(cx, cx.tcx.item_name(did), None, false, vec![], substs);
1599                 ResolvedPath { path, param_names: None, did, is_generic: false }
1600             }
1601             ty::Foreign(did) => {
1602                 inline::record_extern_fqn(cx, did, TypeKind::Foreign);
1603                 let path = external_path(
1604                     cx,
1605                     cx.tcx.item_name(did),
1606                     None,
1607                     false,
1608                     vec![],
1609                     InternalSubsts::empty(),
1610                 );
1611                 ResolvedPath { path, param_names: None, did, is_generic: false }
1612             }
1613             ty::Dynamic(ref obj, ref reg) => {
1614                 // HACK: pick the first `did` as the `did` of the trait object. Someone
1615                 // might want to implement "native" support for marker-trait-only
1616                 // trait objects.
1617                 let mut dids = obj.principal_def_id().into_iter().chain(obj.auto_traits());
1618                 let did = dids
1619                     .next()
1620                     .unwrap_or_else(|| panic!("found trait object `{:?}` with no traits?", self));
1621                 let substs = match obj.principal() {
1622                     Some(principal) => principal.skip_binder().substs,
1623                     // marker traits have no substs.
1624                     _ => cx.tcx.intern_substs(&[]),
1625                 };
1626
1627                 inline::record_extern_fqn(cx, did, TypeKind::Trait);
1628
1629                 let mut param_names = vec![];
1630                 if let Some(b) = reg.clean(cx) {
1631                     param_names.push(GenericBound::Outlives(b));
1632                 }
1633                 for did in dids {
1634                     let empty = cx.tcx.intern_substs(&[]);
1635                     let path =
1636                         external_path(cx, cx.tcx.item_name(did), Some(did), false, vec![], empty);
1637                     inline::record_extern_fqn(cx, did, TypeKind::Trait);
1638                     let bound = GenericBound::TraitBound(
1639                         PolyTrait {
1640                             trait_: ResolvedPath {
1641                                 path,
1642                                 param_names: None,
1643                                 did,
1644                                 is_generic: false,
1645                             },
1646                             generic_params: Vec::new(),
1647                         },
1648                         hir::TraitBoundModifier::None,
1649                     );
1650                     param_names.push(bound);
1651                 }
1652
1653                 let mut bindings = vec![];
1654                 for pb in obj.projection_bounds() {
1655                     bindings.push(TypeBinding {
1656                         name: cx.tcx.associated_item(pb.item_def_id()).ident.name.clean(cx),
1657                         kind: TypeBindingKind::Equality { ty: pb.skip_binder().ty.clean(cx) },
1658                     });
1659                 }
1660
1661                 let path =
1662                     external_path(cx, cx.tcx.item_name(did), Some(did), false, bindings, substs);
1663                 ResolvedPath { path, param_names: Some(param_names), did, is_generic: false }
1664             }
1665             ty::Tuple(ref t) => {
1666                 Tuple(t.iter().map(|t| t.expect_ty()).collect::<Vec<_>>().clean(cx))
1667             }
1668
1669             ty::Projection(ref data) => data.clean(cx),
1670
1671             ty::Param(ref p) => {
1672                 if let Some(bounds) = cx.impl_trait_bounds.borrow_mut().remove(&p.index.into()) {
1673                     ImplTrait(bounds)
1674                 } else {
1675                     Generic(p.name.to_string())
1676                 }
1677             }
1678
1679             ty::Opaque(def_id, substs) => {
1680                 // Grab the "TraitA + TraitB" from `impl TraitA + TraitB`,
1681                 // by looking up the projections associated with the def_id.
1682                 let predicates_of = cx.tcx.explicit_predicates_of(def_id);
1683                 let substs = cx.tcx.lift(&substs).expect("Opaque lift failed");
1684                 let bounds = predicates_of.instantiate(cx.tcx, substs);
1685                 let mut regions = vec![];
1686                 let mut has_sized = false;
1687                 let mut bounds = bounds
1688                     .predicates
1689                     .iter()
1690                     .filter_map(|predicate| {
1691                         // Note: The substs of opaque types can contain unbound variables,
1692                         // meaning that we have to use `ignore_quantifiers_with_unbound_vars` here.
1693                         let trait_ref = match predicate.bound_atom(cx.tcx).skip_binder() {
1694                             ty::PredicateAtom::Trait(tr, _constness) => {
1695                                 ty::Binder::bind(tr.trait_ref)
1696                             }
1697                             ty::PredicateAtom::TypeOutlives(ty::OutlivesPredicate(_ty, reg)) => {
1698                                 if let Some(r) = reg.clean(cx) {
1699                                     regions.push(GenericBound::Outlives(r));
1700                                 }
1701                                 return None;
1702                             }
1703                             _ => return None,
1704                         };
1705
1706                         if let Some(sized) = cx.tcx.lang_items().sized_trait() {
1707                             if trait_ref.def_id() == sized {
1708                                 has_sized = true;
1709                                 return None;
1710                             }
1711                         }
1712
1713                         let bounds: Vec<_> = bounds
1714                             .predicates
1715                             .iter()
1716                             .filter_map(|pred| {
1717                                 if let ty::PredicateAtom::Projection(proj) =
1718                                     pred.bound_atom(cx.tcx).skip_binder()
1719                                 {
1720                                     if proj.projection_ty.trait_ref(cx.tcx)
1721                                         == trait_ref.skip_binder()
1722                                     {
1723                                         Some(TypeBinding {
1724                                             name: cx
1725                                                 .tcx
1726                                                 .associated_item(proj.projection_ty.item_def_id)
1727                                                 .ident
1728                                                 .name
1729                                                 .clean(cx),
1730                                             kind: TypeBindingKind::Equality {
1731                                                 ty: proj.ty.clean(cx),
1732                                             },
1733                                         })
1734                                     } else {
1735                                         None
1736                                     }
1737                                 } else {
1738                                     None
1739                                 }
1740                             })
1741                             .collect();
1742
1743                         Some((trait_ref, &bounds[..]).clean(cx))
1744                     })
1745                     .collect::<Vec<_>>();
1746                 bounds.extend(regions);
1747                 if !has_sized && !bounds.is_empty() {
1748                     bounds.insert(0, GenericBound::maybe_sized(cx));
1749                 }
1750                 ImplTrait(bounds)
1751             }
1752
1753             ty::Closure(..) | ty::Generator(..) => Tuple(vec![]), // FIXME(pcwalton)
1754
1755             ty::Bound(..) => panic!("Bound"),
1756             ty::Placeholder(..) => panic!("Placeholder"),
1757             ty::GeneratorWitness(..) => panic!("GeneratorWitness"),
1758             ty::Infer(..) => panic!("Infer"),
1759             ty::Error(_) => panic!("Error"),
1760         }
1761     }
1762 }
1763
1764 impl<'tcx> Clean<Constant> for ty::Const<'tcx> {
1765     fn clean(&self, cx: &DocContext<'_>) -> Constant {
1766         Constant {
1767             type_: self.ty.clean(cx),
1768             expr: format!("{}", self),
1769             value: None,
1770             is_literal: false,
1771         }
1772     }
1773 }
1774
1775 impl Clean<Item> for hir::StructField<'_> {
1776     fn clean(&self, cx: &DocContext<'_>) -> Item {
1777         let local_did = cx.tcx.hir().local_def_id(self.hir_id);
1778
1779         Item {
1780             name: Some(self.ident.name).clean(cx),
1781             attrs: self.attrs.clean(cx),
1782             source: self.span.clean(cx),
1783             visibility: self.vis.clean(cx),
1784             stability: get_stability(cx, local_did.to_def_id()),
1785             deprecation: get_deprecation(cx, local_did.to_def_id()),
1786             def_id: local_did.to_def_id(),
1787             inner: StructFieldItem(self.ty.clean(cx)),
1788         }
1789     }
1790 }
1791
1792 impl Clean<Item> for ty::FieldDef {
1793     fn clean(&self, cx: &DocContext<'_>) -> Item {
1794         Item {
1795             name: Some(self.ident.name).clean(cx),
1796             attrs: cx.tcx.get_attrs(self.did).clean(cx),
1797             source: cx.tcx.def_span(self.did).clean(cx),
1798             visibility: self.vis.clean(cx),
1799             stability: get_stability(cx, self.did),
1800             deprecation: get_deprecation(cx, self.did),
1801             def_id: self.did,
1802             inner: StructFieldItem(cx.tcx.type_of(self.did).clean(cx)),
1803         }
1804     }
1805 }
1806
1807 impl Clean<Visibility> for hir::Visibility<'_> {
1808     fn clean(&self, cx: &DocContext<'_>) -> Visibility {
1809         match self.node {
1810             hir::VisibilityKind::Public => Visibility::Public,
1811             hir::VisibilityKind::Inherited => Visibility::Inherited,
1812             hir::VisibilityKind::Crate(_) => Visibility::Crate,
1813             hir::VisibilityKind::Restricted { ref path, .. } => {
1814                 let path = path.clean(cx);
1815                 let did = register_res(cx, path.res);
1816                 Visibility::Restricted(did, path)
1817             }
1818         }
1819     }
1820 }
1821
1822 impl Clean<Visibility> for ty::Visibility {
1823     fn clean(&self, _: &DocContext<'_>) -> Visibility {
1824         if *self == ty::Visibility::Public { Public } else { Inherited }
1825     }
1826 }
1827
1828 impl Clean<Item> for doctree::Struct<'_> {
1829     fn clean(&self, cx: &DocContext<'_>) -> Item {
1830         Item {
1831             name: Some(self.name.clean(cx)),
1832             attrs: self.attrs.clean(cx),
1833             source: self.whence.clean(cx),
1834             def_id: cx.tcx.hir().local_def_id(self.id).to_def_id(),
1835             visibility: self.vis.clean(cx),
1836             stability: cx.stability(self.id).clean(cx),
1837             deprecation: cx.deprecation(self.id).clean(cx),
1838             inner: StructItem(Struct {
1839                 struct_type: self.struct_type,
1840                 generics: self.generics.clean(cx),
1841                 fields: self.fields.clean(cx),
1842                 fields_stripped: false,
1843             }),
1844         }
1845     }
1846 }
1847
1848 impl Clean<Item> for doctree::Union<'_> {
1849     fn clean(&self, cx: &DocContext<'_>) -> Item {
1850         Item {
1851             name: Some(self.name.clean(cx)),
1852             attrs: self.attrs.clean(cx),
1853             source: self.whence.clean(cx),
1854             def_id: cx.tcx.hir().local_def_id(self.id).to_def_id(),
1855             visibility: self.vis.clean(cx),
1856             stability: cx.stability(self.id).clean(cx),
1857             deprecation: cx.deprecation(self.id).clean(cx),
1858             inner: UnionItem(Union {
1859                 struct_type: self.struct_type,
1860                 generics: self.generics.clean(cx),
1861                 fields: self.fields.clean(cx),
1862                 fields_stripped: false,
1863             }),
1864         }
1865     }
1866 }
1867
1868 impl Clean<VariantStruct> for rustc_hir::VariantData<'_> {
1869     fn clean(&self, cx: &DocContext<'_>) -> VariantStruct {
1870         VariantStruct {
1871             struct_type: doctree::struct_type_from_def(self),
1872             fields: self.fields().iter().map(|x| x.clean(cx)).collect(),
1873             fields_stripped: false,
1874         }
1875     }
1876 }
1877
1878 impl Clean<Item> for doctree::Enum<'_> {
1879     fn clean(&self, cx: &DocContext<'_>) -> Item {
1880         Item {
1881             name: Some(self.name.clean(cx)),
1882             attrs: self.attrs.clean(cx),
1883             source: self.whence.clean(cx),
1884             def_id: cx.tcx.hir().local_def_id(self.id).to_def_id(),
1885             visibility: self.vis.clean(cx),
1886             stability: cx.stability(self.id).clean(cx),
1887             deprecation: cx.deprecation(self.id).clean(cx),
1888             inner: EnumItem(Enum {
1889                 variants: self.variants.iter().map(|v| v.clean(cx)).collect(),
1890                 generics: self.generics.clean(cx),
1891                 variants_stripped: false,
1892             }),
1893         }
1894     }
1895 }
1896
1897 impl Clean<Item> for doctree::Variant<'_> {
1898     fn clean(&self, cx: &DocContext<'_>) -> Item {
1899         Item {
1900             name: Some(self.name.clean(cx)),
1901             attrs: self.attrs.clean(cx),
1902             source: self.whence.clean(cx),
1903             visibility: Inherited,
1904             stability: cx.stability(self.id).clean(cx),
1905             deprecation: cx.deprecation(self.id).clean(cx),
1906             def_id: cx.tcx.hir().local_def_id(self.id).to_def_id(),
1907             inner: VariantItem(Variant { kind: self.def.clean(cx) }),
1908         }
1909     }
1910 }
1911
1912 impl Clean<Item> for ty::VariantDef {
1913     fn clean(&self, cx: &DocContext<'_>) -> Item {
1914         let kind = match self.ctor_kind {
1915             CtorKind::Const => VariantKind::CLike,
1916             CtorKind::Fn => VariantKind::Tuple(
1917                 self.fields.iter().map(|f| cx.tcx.type_of(f.did).clean(cx)).collect(),
1918             ),
1919             CtorKind::Fictive => VariantKind::Struct(VariantStruct {
1920                 struct_type: doctree::Plain,
1921                 fields_stripped: false,
1922                 fields: self
1923                     .fields
1924                     .iter()
1925                     .map(|field| Item {
1926                         source: cx.tcx.def_span(field.did).clean(cx),
1927                         name: Some(field.ident.name.clean(cx)),
1928                         attrs: cx.tcx.get_attrs(field.did).clean(cx),
1929                         visibility: field.vis.clean(cx),
1930                         def_id: field.did,
1931                         stability: get_stability(cx, field.did),
1932                         deprecation: get_deprecation(cx, field.did),
1933                         inner: StructFieldItem(cx.tcx.type_of(field.did).clean(cx)),
1934                     })
1935                     .collect(),
1936             }),
1937         };
1938         Item {
1939             name: Some(self.ident.clean(cx)),
1940             attrs: inline::load_attrs(cx, self.def_id).clean(cx),
1941             source: cx.tcx.def_span(self.def_id).clean(cx),
1942             visibility: Inherited,
1943             def_id: self.def_id,
1944             inner: VariantItem(Variant { kind }),
1945             stability: get_stability(cx, self.def_id),
1946             deprecation: get_deprecation(cx, self.def_id),
1947         }
1948     }
1949 }
1950
1951 impl Clean<VariantKind> for hir::VariantData<'_> {
1952     fn clean(&self, cx: &DocContext<'_>) -> VariantKind {
1953         match self {
1954             hir::VariantData::Struct(..) => VariantKind::Struct(self.clean(cx)),
1955             hir::VariantData::Tuple(..) => {
1956                 VariantKind::Tuple(self.fields().iter().map(|x| x.ty.clean(cx)).collect())
1957             }
1958             hir::VariantData::Unit(..) => VariantKind::CLike,
1959         }
1960     }
1961 }
1962
1963 impl Clean<Span> for rustc_span::Span {
1964     fn clean(&self, cx: &DocContext<'_>) -> Span {
1965         if self.is_dummy() {
1966             return Span::empty();
1967         }
1968
1969         let sm = cx.sess().source_map();
1970         let filename = sm.span_to_filename(*self);
1971         let lo = sm.lookup_char_pos(self.lo());
1972         let hi = sm.lookup_char_pos(self.hi());
1973         Span {
1974             filename,
1975             cnum: lo.file.cnum,
1976             loline: lo.line,
1977             locol: lo.col.to_usize(),
1978             hiline: hi.line,
1979             hicol: hi.col.to_usize(),
1980             original: *self,
1981         }
1982     }
1983 }
1984
1985 impl Clean<Path> for hir::Path<'_> {
1986     fn clean(&self, cx: &DocContext<'_>) -> Path {
1987         Path {
1988             global: self.is_global(),
1989             res: self.res,
1990             segments: if self.is_global() { &self.segments[1..] } else { &self.segments }.clean(cx),
1991         }
1992     }
1993 }
1994
1995 impl Clean<GenericArgs> for hir::GenericArgs<'_> {
1996     fn clean(&self, cx: &DocContext<'_>) -> GenericArgs {
1997         if self.parenthesized {
1998             let output = self.bindings[0].ty().clean(cx);
1999             GenericArgs::Parenthesized {
2000                 inputs: self.inputs().clean(cx),
2001                 output: if output != Type::Tuple(Vec::new()) { Some(output) } else { None },
2002             }
2003         } else {
2004             GenericArgs::AngleBracketed {
2005                 args: self
2006                     .args
2007                     .iter()
2008                     .map(|arg| match arg {
2009                         hir::GenericArg::Lifetime(lt) if !lt.is_elided() => {
2010                             GenericArg::Lifetime(lt.clean(cx))
2011                         }
2012                         hir::GenericArg::Lifetime(_) => GenericArg::Lifetime(Lifetime::elided()),
2013                         hir::GenericArg::Type(ty) => GenericArg::Type(ty.clean(cx)),
2014                         hir::GenericArg::Const(ct) => GenericArg::Const(ct.clean(cx)),
2015                     })
2016                     .collect(),
2017                 bindings: self.bindings.clean(cx),
2018             }
2019         }
2020     }
2021 }
2022
2023 impl Clean<PathSegment> for hir::PathSegment<'_> {
2024     fn clean(&self, cx: &DocContext<'_>) -> PathSegment {
2025         PathSegment { name: self.ident.name.clean(cx), args: self.generic_args().clean(cx) }
2026     }
2027 }
2028
2029 impl Clean<String> for Ident {
2030     #[inline]
2031     fn clean(&self, cx: &DocContext<'_>) -> String {
2032         self.name.clean(cx)
2033     }
2034 }
2035
2036 impl Clean<String> for Symbol {
2037     #[inline]
2038     fn clean(&self, _: &DocContext<'_>) -> String {
2039         self.to_string()
2040     }
2041 }
2042
2043 impl Clean<Item> for doctree::Typedef<'_> {
2044     fn clean(&self, cx: &DocContext<'_>) -> Item {
2045         let type_ = self.ty.clean(cx);
2046         let item_type = type_.def_id().and_then(|did| inline::build_ty(cx, did));
2047         Item {
2048             name: Some(self.name.clean(cx)),
2049             attrs: self.attrs.clean(cx),
2050             source: self.whence.clean(cx),
2051             def_id: cx.tcx.hir().local_def_id(self.id).to_def_id(),
2052             visibility: self.vis.clean(cx),
2053             stability: cx.stability(self.id).clean(cx),
2054             deprecation: cx.deprecation(self.id).clean(cx),
2055             inner: TypedefItem(Typedef { type_, generics: self.gen.clean(cx), item_type }, false),
2056         }
2057     }
2058 }
2059
2060 impl Clean<Item> for doctree::OpaqueTy<'_> {
2061     fn clean(&self, cx: &DocContext<'_>) -> Item {
2062         Item {
2063             name: Some(self.name.clean(cx)),
2064             attrs: self.attrs.clean(cx),
2065             source: self.whence.clean(cx),
2066             def_id: cx.tcx.hir().local_def_id(self.id).to_def_id(),
2067             visibility: self.vis.clean(cx),
2068             stability: cx.stability(self.id).clean(cx),
2069             deprecation: cx.deprecation(self.id).clean(cx),
2070             inner: OpaqueTyItem(
2071                 OpaqueTy {
2072                     bounds: self.opaque_ty.bounds.clean(cx),
2073                     generics: self.opaque_ty.generics.clean(cx),
2074                 },
2075                 false,
2076             ),
2077         }
2078     }
2079 }
2080
2081 impl Clean<BareFunctionDecl> for hir::BareFnTy<'_> {
2082     fn clean(&self, cx: &DocContext<'_>) -> BareFunctionDecl {
2083         let (generic_params, decl) = enter_impl_trait(cx, || {
2084             (self.generic_params.clean(cx), (&*self.decl, &self.param_names[..]).clean(cx))
2085         });
2086         BareFunctionDecl { unsafety: self.unsafety, abi: self.abi, decl, generic_params }
2087     }
2088 }
2089
2090 impl Clean<Item> for doctree::Static<'_> {
2091     fn clean(&self, cx: &DocContext<'_>) -> Item {
2092         debug!("cleaning static {}: {:?}", self.name.clean(cx), self);
2093         Item {
2094             name: Some(self.name.clean(cx)),
2095             attrs: self.attrs.clean(cx),
2096             source: self.whence.clean(cx),
2097             def_id: cx.tcx.hir().local_def_id(self.id).to_def_id(),
2098             visibility: self.vis.clean(cx),
2099             stability: cx.stability(self.id).clean(cx),
2100             deprecation: cx.deprecation(self.id).clean(cx),
2101             inner: StaticItem(Static {
2102                 type_: self.type_.clean(cx),
2103                 mutability: self.mutability,
2104                 expr: print_const_expr(cx, self.expr),
2105             }),
2106         }
2107     }
2108 }
2109
2110 impl Clean<Item> for doctree::Constant<'_> {
2111     fn clean(&self, cx: &DocContext<'_>) -> Item {
2112         let def_id = cx.tcx.hir().local_def_id(self.id);
2113
2114         Item {
2115             name: Some(self.name.clean(cx)),
2116             attrs: self.attrs.clean(cx),
2117             source: self.whence.clean(cx),
2118             def_id: def_id.to_def_id(),
2119             visibility: self.vis.clean(cx),
2120             stability: cx.stability(self.id).clean(cx),
2121             deprecation: cx.deprecation(self.id).clean(cx),
2122             inner: ConstantItem(Constant {
2123                 type_: self.type_.clean(cx),
2124                 expr: print_const_expr(cx, self.expr),
2125                 value: print_evaluated_const(cx, def_id.to_def_id()),
2126                 is_literal: is_literal_expr(cx, self.expr.hir_id),
2127             }),
2128         }
2129     }
2130 }
2131
2132 impl Clean<ImplPolarity> for ty::ImplPolarity {
2133     fn clean(&self, _: &DocContext<'_>) -> ImplPolarity {
2134         match self {
2135             &ty::ImplPolarity::Positive |
2136             // FIXME: do we want to do something else here?
2137             &ty::ImplPolarity::Reservation => ImplPolarity::Positive,
2138             &ty::ImplPolarity::Negative => ImplPolarity::Negative,
2139         }
2140     }
2141 }
2142
2143 impl Clean<Vec<Item>> for doctree::Impl<'_> {
2144     fn clean(&self, cx: &DocContext<'_>) -> Vec<Item> {
2145         let mut ret = Vec::new();
2146         let trait_ = self.trait_.clean(cx);
2147         let items = self.items.iter().map(|ii| ii.clean(cx)).collect::<Vec<_>>();
2148         let def_id = cx.tcx.hir().local_def_id(self.id);
2149
2150         // If this impl block is an implementation of the Deref trait, then we
2151         // need to try inlining the target's inherent impl blocks as well.
2152         if trait_.def_id() == cx.tcx.lang_items().deref_trait() {
2153             build_deref_target_impls(cx, &items, &mut ret);
2154         }
2155
2156         let provided: FxHashSet<String> = trait_
2157             .def_id()
2158             .map(|did| {
2159                 cx.tcx.provided_trait_methods(did).map(|meth| meth.ident.to_string()).collect()
2160             })
2161             .unwrap_or_default();
2162
2163         let for_ = self.for_.clean(cx);
2164         let type_alias = for_.def_id().and_then(|did| match cx.tcx.def_kind(did) {
2165             DefKind::TyAlias => Some(cx.tcx.type_of(did).clean(cx)),
2166             _ => None,
2167         });
2168         let make_item = |trait_: Option<Type>, for_: Type, items: Vec<Item>| Item {
2169             name: None,
2170             attrs: self.attrs.clean(cx),
2171             source: self.whence.clean(cx),
2172             def_id: def_id.to_def_id(),
2173             visibility: self.vis.clean(cx),
2174             stability: cx.stability(self.id).clean(cx),
2175             deprecation: cx.deprecation(self.id).clean(cx),
2176             inner: ImplItem(Impl {
2177                 unsafety: self.unsafety,
2178                 generics: self.generics.clean(cx),
2179                 provided_trait_methods: provided.clone(),
2180                 trait_,
2181                 for_,
2182                 items,
2183                 polarity: Some(cx.tcx.impl_polarity(def_id).clean(cx)),
2184                 synthetic: false,
2185                 blanket_impl: None,
2186             }),
2187         };
2188         if let Some(type_alias) = type_alias {
2189             ret.push(make_item(trait_.clone(), type_alias, items.clone()));
2190         }
2191         ret.push(make_item(trait_, for_, items));
2192         ret
2193     }
2194 }
2195
2196 impl Clean<Vec<Item>> for doctree::ExternCrate<'_> {
2197     fn clean(&self, cx: &DocContext<'_>) -> Vec<Item> {
2198         let please_inline = self.vis.node.is_pub()
2199             && self.attrs.iter().any(|a| {
2200                 a.has_name(sym::doc)
2201                     && match a.meta_item_list() {
2202                         Some(l) => attr::list_contains_name(&l, sym::inline),
2203                         None => false,
2204                     }
2205             });
2206
2207         if please_inline {
2208             let mut visited = FxHashSet::default();
2209
2210             let res = Res::Def(DefKind::Mod, DefId { krate: self.cnum, index: CRATE_DEF_INDEX });
2211
2212             if let Some(items) =
2213                 inline::try_inline(cx, res, self.name, Some(self.attrs), &mut visited)
2214             {
2215                 return items;
2216             }
2217         }
2218
2219         vec![Item {
2220             name: None,
2221             attrs: self.attrs.clean(cx),
2222             source: self.whence.clean(cx),
2223             def_id: DefId { krate: self.cnum, index: CRATE_DEF_INDEX },
2224             visibility: self.vis.clean(cx),
2225             stability: None,
2226             deprecation: None,
2227             inner: ExternCrateItem(self.name.clean(cx), self.path.clone()),
2228         }]
2229     }
2230 }
2231
2232 impl Clean<Vec<Item>> for doctree::Import<'_> {
2233     fn clean(&self, cx: &DocContext<'_>) -> Vec<Item> {
2234         // We consider inlining the documentation of `pub use` statements, but we
2235         // forcefully don't inline if this is not public or if the
2236         // #[doc(no_inline)] attribute is present.
2237         // Don't inline doc(hidden) imports so they can be stripped at a later stage.
2238         let mut denied = !self.vis.node.is_pub()
2239             || self.attrs.iter().any(|a| {
2240                 a.has_name(sym::doc)
2241                     && match a.meta_item_list() {
2242                         Some(l) => {
2243                             attr::list_contains_name(&l, sym::no_inline)
2244                                 || attr::list_contains_name(&l, sym::hidden)
2245                         }
2246                         None => false,
2247                     }
2248             });
2249         // Also check whether imports were asked to be inlined, in case we're trying to re-export a
2250         // crate in Rust 2018+
2251         let please_inline = self.attrs.lists(sym::doc).has_word(sym::inline);
2252         let path = self.path.clean(cx);
2253         let inner = if self.glob {
2254             if !denied {
2255                 let mut visited = FxHashSet::default();
2256                 if let Some(items) = inline::try_inline_glob(cx, path.res, &mut visited) {
2257                     return items;
2258                 }
2259             }
2260
2261             Import::Glob(resolve_use_source(cx, path))
2262         } else {
2263             let name = self.name;
2264             if !please_inline {
2265                 if let Res::Def(DefKind::Mod, did) = path.res {
2266                     if !did.is_local() && did.index == CRATE_DEF_INDEX {
2267                         // if we're `pub use`ing an extern crate root, don't inline it unless we
2268                         // were specifically asked for it
2269                         denied = true;
2270                     }
2271                 }
2272             }
2273             if !denied {
2274                 let mut visited = FxHashSet::default();
2275                 if let Some(items) =
2276                     inline::try_inline(cx, path.res, name, Some(self.attrs), &mut visited)
2277                 {
2278                     return items;
2279                 }
2280             }
2281             Import::Simple(name.clean(cx), resolve_use_source(cx, path))
2282         };
2283
2284         vec![Item {
2285             name: None,
2286             attrs: self.attrs.clean(cx),
2287             source: self.whence.clean(cx),
2288             def_id: DefId::local(CRATE_DEF_INDEX),
2289             visibility: self.vis.clean(cx),
2290             stability: None,
2291             deprecation: None,
2292             inner: ImportItem(inner),
2293         }]
2294     }
2295 }
2296
2297 impl Clean<Item> for doctree::ForeignItem<'_> {
2298     fn clean(&self, cx: &DocContext<'_>) -> Item {
2299         let inner = match self.kind {
2300             hir::ForeignItemKind::Fn(ref decl, ref names, ref generics) => {
2301                 let abi = cx.tcx.hir().get_foreign_abi(self.id);
2302                 let (generics, decl) =
2303                     enter_impl_trait(cx, || (generics.clean(cx), (&**decl, &names[..]).clean(cx)));
2304                 let (all_types, ret_types) = get_all_types(&generics, &decl, cx);
2305                 ForeignFunctionItem(Function {
2306                     decl,
2307                     generics,
2308                     header: hir::FnHeader {
2309                         unsafety: hir::Unsafety::Unsafe,
2310                         abi,
2311                         constness: hir::Constness::NotConst,
2312                         asyncness: hir::IsAsync::NotAsync,
2313                     },
2314                     all_types,
2315                     ret_types,
2316                 })
2317             }
2318             hir::ForeignItemKind::Static(ref ty, mutbl) => ForeignStaticItem(Static {
2319                 type_: ty.clean(cx),
2320                 mutability: *mutbl,
2321                 expr: String::new(),
2322             }),
2323             hir::ForeignItemKind::Type => ForeignTypeItem,
2324         };
2325
2326         Item {
2327             name: Some(self.name.clean(cx)),
2328             attrs: self.attrs.clean(cx),
2329             source: self.whence.clean(cx),
2330             def_id: cx.tcx.hir().local_def_id(self.id).to_def_id(),
2331             visibility: self.vis.clean(cx),
2332             stability: cx.stability(self.id).clean(cx),
2333             deprecation: cx.deprecation(self.id).clean(cx),
2334             inner,
2335         }
2336     }
2337 }
2338
2339 impl Clean<Item> for doctree::Macro<'_> {
2340     fn clean(&self, cx: &DocContext<'_>) -> Item {
2341         let name = self.name.clean(cx);
2342         Item {
2343             name: Some(name.clone()),
2344             attrs: self.attrs.clean(cx),
2345             source: self.whence.clean(cx),
2346             visibility: Public,
2347             stability: cx.stability(self.hid).clean(cx),
2348             deprecation: cx.deprecation(self.hid).clean(cx),
2349             def_id: self.def_id,
2350             inner: MacroItem(Macro {
2351                 source: format!(
2352                     "macro_rules! {} {{\n{}}}",
2353                     name,
2354                     self.matchers
2355                         .iter()
2356                         .map(|span| { format!("    {} => {{ ... }};\n", span.to_src(cx)) })
2357                         .collect::<String>()
2358                 ),
2359                 imported_from: self.imported_from.clean(cx),
2360             }),
2361         }
2362     }
2363 }
2364
2365 impl Clean<Item> for doctree::ProcMacro<'_> {
2366     fn clean(&self, cx: &DocContext<'_>) -> Item {
2367         Item {
2368             name: Some(self.name.clean(cx)),
2369             attrs: self.attrs.clean(cx),
2370             source: self.whence.clean(cx),
2371             visibility: Public,
2372             stability: cx.stability(self.id).clean(cx),
2373             deprecation: cx.deprecation(self.id).clean(cx),
2374             def_id: cx.tcx.hir().local_def_id(self.id).to_def_id(),
2375             inner: ProcMacroItem(ProcMacro { kind: self.kind, helpers: self.helpers.clean(cx) }),
2376         }
2377     }
2378 }
2379
2380 impl Clean<Stability> for attr::Stability {
2381     fn clean(&self, _: &DocContext<'_>) -> Stability {
2382         Stability {
2383             level: stability::StabilityLevel::from_attr_level(&self.level),
2384             feature: self.feature.to_string(),
2385             since: match self.level {
2386                 attr::Stable { ref since } => since.to_string(),
2387                 _ => String::new(),
2388             },
2389             unstable_reason: match self.level {
2390                 attr::Unstable { reason: Some(ref reason), .. } => Some(reason.to_string()),
2391                 _ => None,
2392             },
2393             issue: match self.level {
2394                 attr::Unstable { issue, .. } => issue,
2395                 _ => None,
2396             },
2397         }
2398     }
2399 }
2400
2401 impl Clean<Deprecation> for attr::Deprecation {
2402     fn clean(&self, _: &DocContext<'_>) -> Deprecation {
2403         Deprecation {
2404             since: self.since.map(|s| s.to_string()).filter(|s| !s.is_empty()),
2405             note: self.note.map(|n| n.to_string()).filter(|n| !n.is_empty()),
2406             is_since_rustc_version: self.is_since_rustc_version,
2407         }
2408     }
2409 }
2410
2411 impl Clean<TypeBinding> for hir::TypeBinding<'_> {
2412     fn clean(&self, cx: &DocContext<'_>) -> TypeBinding {
2413         TypeBinding { name: self.ident.name.clean(cx), kind: self.kind.clean(cx) }
2414     }
2415 }
2416
2417 impl Clean<TypeBindingKind> for hir::TypeBindingKind<'_> {
2418     fn clean(&self, cx: &DocContext<'_>) -> TypeBindingKind {
2419         match *self {
2420             hir::TypeBindingKind::Equality { ref ty } => {
2421                 TypeBindingKind::Equality { ty: ty.clean(cx) }
2422             }
2423             hir::TypeBindingKind::Constraint { ref bounds } => {
2424                 TypeBindingKind::Constraint { bounds: bounds.iter().map(|b| b.clean(cx)).collect() }
2425             }
2426         }
2427     }
2428 }
2429
2430 enum SimpleBound {
2431     TraitBound(Vec<PathSegment>, Vec<SimpleBound>, Vec<GenericParamDef>, hir::TraitBoundModifier),
2432     Outlives(Lifetime),
2433 }
2434
2435 impl From<GenericBound> for SimpleBound {
2436     fn from(bound: GenericBound) -> Self {
2437         match bound.clone() {
2438             GenericBound::Outlives(l) => SimpleBound::Outlives(l),
2439             GenericBound::TraitBound(t, mod_) => match t.trait_ {
2440                 Type::ResolvedPath { path, param_names, .. } => SimpleBound::TraitBound(
2441                     path.segments,
2442                     param_names.map_or_else(Vec::new, |v| {
2443                         v.iter().map(|p| SimpleBound::from(p.clone())).collect()
2444                     }),
2445                     t.generic_params,
2446                     mod_,
2447                 ),
2448                 _ => panic!("Unexpected bound {:?}", bound),
2449             },
2450         }
2451     }
2452 }