src/librustdoc/clean/mod.rs

   1 // Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 //! This module contains the "cleaned" pieces of the AST, and the functions
  12 //! that clean them.
  13
  14 pub use self::Type::*;
  15 pub use self::Mutability::*;
  16 pub use self::ItemEnum::*;
  17 pub use self::TyParamBound::*;
  18 pub use self::SelfTy::*;
  19 pub use self::FunctionRetTy::*;
  20 pub use self::Visibility::*;
  21
  22 use syntax;
  23 use rustc_target::spec::abi::Abi;
  24 use syntax::ast::{self, AttrStyle, Ident};
  25 use syntax::attr;
  26 use syntax::codemap::{dummy_spanned, Spanned};
  27 use syntax::feature_gate::UnstableFeatures;
  28 use syntax::ptr::P;
  29 use syntax::symbol::keywords;
  30 use syntax::symbol::{Symbol, InternedString};
  31 use syntax_pos::{self, DUMMY_SP, Pos, FileName};
  32
  33 use rustc::middle::const_val::ConstVal;
  34 use rustc::middle::privacy::AccessLevels;
  35 use rustc::middle::resolve_lifetime as rl;
  36 use rustc::ty::fold::TypeFolder;
  37 use rustc::middle::lang_items;
  38 use rustc::mir::interpret::GlobalId;
  39 use rustc::hir::{self, HirVec};
  40 use rustc::hir::def::{self, Def, CtorKind};
  41 use rustc::hir::def_id::{CrateNum, DefId, DefIndex, CRATE_DEF_INDEX, LOCAL_CRATE};
  42 use rustc::hir::def_id::DefIndexAddressSpace;
  43 use rustc::ty::subst::Substs;
  44 use rustc::ty::{self, TyCtxt, Region, RegionVid, Ty, AdtKind};
  45 use rustc::middle::stability;
  46 use rustc::util::nodemap::{FxHashMap, FxHashSet};
  47 use rustc_typeck::hir_ty_to_ty;
  48 use rustc::infer::region_constraints::{RegionConstraintData, Constraint};
  49 use std::collections::hash_map::Entry;
  50 use std::fmt;
  51
  52 use std::default::Default;
  53 use std::{mem, slice, vec};
  54 use std::iter::{FromIterator, once};
  55 use rustc_data_structures::sync::Lrc;
  56 use std::rc::Rc;
  57 use std::cell::RefCell;
  58 use std::sync::Arc;
  59 use std::u32;
  60
  61 use core::{self, DocContext};
  62 use doctree;
  63 use visit_ast;
  64 use html::render::{cache, ExternalLocation};
  65 use html::item_type::ItemType;
  66 use html::markdown::markdown_links;
  67
  68 pub mod inline;
  69 pub mod cfg;
  70 mod simplify;
  71 mod auto_trait;
  72
  73 use self::cfg::Cfg;
  74 use self::auto_trait::AutoTraitFinder;
  75
  76 thread_local!(static MAX_DEF_ID: RefCell<FxHashMap<CrateNum, DefId>> = RefCell::new(FxHashMap()));
  77
  78 const FN_OUTPUT_NAME: &'static str = "Output";
  79
  80 // extract the stability index for a node from tcx, if possible
  81 fn get_stability(cx: &DocContext, def_id: DefId) -> Option<Stability> {
  82     cx.tcx.lookup_stability(def_id).clean(cx)
  83 }
  84
  85 fn get_deprecation(cx: &DocContext, def_id: DefId) -> Option<Deprecation> {
  86     cx.tcx.lookup_deprecation(def_id).clean(cx)
  87 }
  88
  89 pub trait Clean<T> {
  90     fn clean(&self, cx: &DocContext) -> T;
  91 }
  92
  93 impl<T: Clean<U>, U> Clean<Vec<U>> for [T] {
  94     fn clean(&self, cx: &DocContext) -> Vec<U> {
  95         self.iter().map(|x| x.clean(cx)).collect()
  96     }
  97 }
  98
  99 impl<T: Clean<U>, U> Clean<U> for P<T> {
 100     fn clean(&self, cx: &DocContext) -> U {
 101         (**self).clean(cx)
 102     }
 103 }
 104
 105 impl<T: Clean<U>, U> Clean<U> for Rc<T> {
 106     fn clean(&self, cx: &DocContext) -> U {
 107         (**self).clean(cx)
 108     }
 109 }
 110
 111 impl<T: Clean<U>, U> Clean<Option<U>> for Option<T> {
 112     fn clean(&self, cx: &DocContext) -> Option<U> {
 113         self.as_ref().map(|v| v.clean(cx))
 114     }
 115 }
 116
 117 impl<T, U> Clean<U> for ty::Binder<T> where T: Clean<U> {
 118     fn clean(&self, cx: &DocContext) -> U {
 119         self.skip_binder().clean(cx)
 120     }
 121 }
 122
 123 impl<T: Clean<U>, U> Clean<Vec<U>> for P<[T]> {
 124     fn clean(&self, cx: &DocContext) -> Vec<U> {
 125         self.iter().map(|x| x.clean(cx)).collect()
 126     }
 127 }
 128
 129 #[derive(Clone, Debug)]
 130 pub struct Crate {
 131     pub name: String,
 132     pub version: Option<String>,
 133     pub src: FileName,
 134     pub module: Option<Item>,
 135     pub externs: Vec<(CrateNum, ExternalCrate)>,
 136     pub primitives: Vec<(DefId, PrimitiveType, Attributes)>,
 137     pub access_levels: Arc<AccessLevels<DefId>>,
 138     // These are later on moved into `CACHEKEY`, leaving the map empty.
 139     // Only here so that they can be filtered through the rustdoc passes.
 140     pub external_traits: FxHashMap<DefId, Trait>,
 141     pub masked_crates: FxHashSet<CrateNum>,
 142 }
 143
 144 impl<'a, 'tcx, 'rcx> Clean<Crate> for visit_ast::RustdocVisitor<'a, 'tcx, 'rcx> {
 145     fn clean(&self, cx: &DocContext) -> Crate {
 146         use ::visit_lib::LibEmbargoVisitor;
 147
 148         {
 149             let mut r = cx.renderinfo.borrow_mut();
 150             r.deref_trait_did = cx.tcx.lang_items().deref_trait();
 151             r.deref_mut_trait_did = cx.tcx.lang_items().deref_mut_trait();
 152             r.owned_box_did = cx.tcx.lang_items().owned_box();
 153         }
 154
 155         let mut externs = Vec::new();
 156         for &cnum in cx.tcx.crates().iter() {
 157             externs.push((cnum, cnum.clean(cx)));
 158             // Analyze doc-reachability for extern items
 159             LibEmbargoVisitor::new(cx).visit_lib(cnum);
 160         }
 161         externs.sort_by(|&(a, _), &(b, _)| a.cmp(&b));
 162
 163         // Clean the crate, translating the entire libsyntax AST to one that is
 164         // understood by rustdoc.
 165         let mut module = self.module.clean(cx);
 166         let mut masked_crates = FxHashSet();
 167
 168         match module.inner {
 169             ModuleItem(ref module) => {
 170                 for it in &module.items {
 171                     if it.is_extern_crate() && it.attrs.has_doc_flag("masked") {
 172                         masked_crates.insert(it.def_id.krate);
 173                     }
 174                 }
 175             }
 176             _ => unreachable!(),
 177         }
 178
 179         let ExternalCrate { name, src, primitives, .. } = LOCAL_CRATE.clean(cx);
 180         {
 181             let m = match module.inner {
 182                 ModuleItem(ref mut m) => m,
 183                 _ => unreachable!(),
 184             };
 185             m.items.extend(primitives.iter().map(|&(def_id, prim, ref attrs)| {
 186                 Item {
 187                     source: Span::empty(),
 188                     name: Some(prim.to_url_str().to_string()),
 189                     attrs: attrs.clone(),
 190                     visibility: Some(Public),
 191                     stability: get_stability(cx, def_id),
 192                     deprecation: get_deprecation(cx, def_id),
 193                     def_id,
 194                     inner: PrimitiveItem(prim),
 195                 }
 196             }));
 197         }
 198
 199         let mut access_levels = cx.access_levels.borrow_mut();
 200         let mut external_traits = cx.external_traits.borrow_mut();
 201
 202         Crate {
 203             name,
 204             version: None,
 205             src,
 206             module: Some(module),
 207             externs,
 208             primitives,
 209             access_levels: Arc::new(mem::replace(&mut access_levels, Default::default())),
 210             external_traits: mem::replace(&mut external_traits, Default::default()),
 211             masked_crates,
 212         }
 213     }
 214 }
 215
 216 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
 217 pub struct ExternalCrate {
 218     pub name: String,
 219     pub src: FileName,
 220     pub attrs: Attributes,
 221     pub primitives: Vec<(DefId, PrimitiveType, Attributes)>,
 222 }
 223
 224 impl Clean<ExternalCrate> for CrateNum {
 225     fn clean(&self, cx: &DocContext) -> ExternalCrate {
 226         let root = DefId { krate: *self, index: CRATE_DEF_INDEX };
 227         let krate_span = cx.tcx.def_span(root);
 228         let krate_src = cx.sess().codemap().span_to_filename(krate_span);
 229
 230         // Collect all inner modules which are tagged as implementations of
 231         // primitives.
 232         //
 233         // Note that this loop only searches the top-level items of the crate,
 234         // and this is intentional. If we were to search the entire crate for an
 235         // item tagged with `#[doc(primitive)]` then we would also have to
 236         // search the entirety of external modules for items tagged
 237         // `#[doc(primitive)]`, which is a pretty inefficient process (decoding
 238         // all that metadata unconditionally).
 239         //
 240         // In order to keep the metadata load under control, the
 241         // `#[doc(primitive)]` feature is explicitly designed to only allow the
 242         // primitive tags to show up as the top level items in a crate.
 243         //
 244         // Also note that this does not attempt to deal with modules tagged
 245         // duplicately for the same primitive. This is handled later on when
 246         // rendering by delegating everything to a hash map.
 247         let as_primitive = |def: Def| {
 248             if let Def::Mod(def_id) = def {
 249                 let attrs = cx.tcx.get_attrs(def_id).clean(cx);
 250                 let mut prim = None;
 251                 for attr in attrs.lists("doc") {
 252                     if let Some(v) = attr.value_str() {
 253                         if attr.check_name("primitive") {
 254                             prim = PrimitiveType::from_str(&v.as_str());
 255                             if prim.is_some() {
 256                                 break;
 257                             }
 258                             // FIXME: should warn on unknown primitives?
 259                         }
 260                     }
 261                 }
 262                 return prim.map(|p| (def_id, p, attrs));
 263             }
 264             None
 265         };
 266         let primitives = if root.is_local() {
 267             cx.tcx.hir.krate().module.item_ids.iter().filter_map(|&id| {
 268                 let item = cx.tcx.hir.expect_item(id.id);
 269                 match item.node {
 270                     hir::ItemMod(_) => {
 271                         as_primitive(Def::Mod(cx.tcx.hir.local_def_id(id.id)))
 272                     }
 273                     hir::ItemUse(ref path, hir::UseKind::Single)
 274                     if item.vis == hir::Visibility::Public => {
 275                         as_primitive(path.def).map(|(_, prim, attrs)| {
 276                             // Pretend the primitive is local.
 277                             (cx.tcx.hir.local_def_id(id.id), prim, attrs)
 278                         })
 279                     }
 280                     _ => None
 281                 }
 282             }).collect()
 283         } else {
 284             cx.tcx.item_children(root).iter().map(|item| item.def)
 285               .filter_map(as_primitive).collect()
 286         };
 287
 288         ExternalCrate {
 289             name: cx.tcx.crate_name(*self).to_string(),
 290             src: krate_src,
 291             attrs: cx.tcx.get_attrs(root).clean(cx),
 292             primitives,
 293         }
 294     }
 295 }
 296
 297 /// Anything with a source location and set of attributes and, optionally, a
 298 /// name. That is, anything that can be documented. This doesn't correspond
 299 /// directly to the AST's concept of an item; it's a strict superset.
 300 #[derive(Clone, RustcEncodable, RustcDecodable)]
 301 pub struct Item {
 302     /// Stringified span
 303     pub source: Span,
 304     /// Not everything has a name. E.g., impls
 305     pub name: Option<String>,
 306     pub attrs: Attributes,
 307     pub inner: ItemEnum,
 308     pub visibility: Option<Visibility>,
 309     pub def_id: DefId,
 310     pub stability: Option<Stability>,
 311     pub deprecation: Option<Deprecation>,
 312 }
 313
 314 impl fmt::Debug for Item {
 315     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
 316
 317         let fake = MAX_DEF_ID.with(|m| m.borrow().get(&self.def_id.krate)
 318                                    .map(|id| self.def_id >= *id).unwrap_or(false));
 319         let def_id: &fmt::Debug = if fake { &"**FAKE**" } else { &self.def_id };
 320
 321         fmt.debug_struct("Item")
 322             .field("source", &self.source)
 323             .field("name", &self.name)
 324             .field("attrs", &self.attrs)
 325             .field("inner", &self.inner)
 326             .field("visibility", &self.visibility)
 327             .field("def_id", def_id)
 328             .field("stability", &self.stability)
 329             .field("deprecation", &self.deprecation)
 330             .finish()
 331     }
 332 }
 333
 334 impl Item {
 335     /// Finds the `doc` attribute as a NameValue and returns the corresponding
 336     /// value found.
 337     pub fn doc_value<'a>(&'a self) -> Option<&'a str> {
 338         self.attrs.doc_value()
 339     }
 340     /// Finds all `doc` attributes as NameValues and returns their corresponding values, joined
 341     /// with newlines.
 342     pub fn collapsed_doc_value(&self) -> Option<String> {
 343         self.attrs.collapsed_doc_value()
 344     }
 345
 346     pub fn links(&self) -> Vec<(String, String)> {
 347         self.attrs.links(&self.def_id.krate)
 348     }
 349
 350     pub fn is_crate(&self) -> bool {
 351         match self.inner {
 352             StrippedItem(box ModuleItem(Module { is_crate: true, ..})) |
 353             ModuleItem(Module { is_crate: true, ..}) => true,
 354             _ => false,
 355         }
 356     }
 357     pub fn is_mod(&self) -> bool {
 358         self.type_() == ItemType::Module
 359     }
 360     pub fn is_trait(&self) -> bool {
 361         self.type_() == ItemType::Trait
 362     }
 363     pub fn is_struct(&self) -> bool {
 364         self.type_() == ItemType::Struct
 365     }
 366     pub fn is_enum(&self) -> bool {
 367         self.type_() == ItemType::Enum
 368     }
 369     pub fn is_fn(&self) -> bool {
 370         self.type_() == ItemType::Function
 371     }
 372     pub fn is_associated_type(&self) -> bool {
 373         self.type_() == ItemType::AssociatedType
 374     }
 375     pub fn is_associated_const(&self) -> bool {
 376         self.type_() == ItemType::AssociatedConst
 377     }
 378     pub fn is_method(&self) -> bool {
 379         self.type_() == ItemType::Method
 380     }
 381     pub fn is_ty_method(&self) -> bool {
 382         self.type_() == ItemType::TyMethod
 383     }
 384     pub fn is_typedef(&self) -> bool {
 385         self.type_() == ItemType::Typedef
 386     }
 387     pub fn is_primitive(&self) -> bool {
 388         self.type_() == ItemType::Primitive
 389     }
 390     pub fn is_union(&self) -> bool {
 391         self.type_() == ItemType::Union
 392     }
 393     pub fn is_import(&self) -> bool {
 394         self.type_() == ItemType::Import
 395     }
 396     pub fn is_extern_crate(&self) -> bool {
 397         self.type_() == ItemType::ExternCrate
 398     }
 399
 400     pub fn is_stripped(&self) -> bool {
 401         match self.inner { StrippedItem(..) => true, _ => false }
 402     }
 403     pub fn has_stripped_fields(&self) -> Option<bool> {
 404         match self.inner {
 405             StructItem(ref _struct) => Some(_struct.fields_stripped),
 406             UnionItem(ref union) => Some(union.fields_stripped),
 407             VariantItem(Variant { kind: VariantKind::Struct(ref vstruct)} ) => {
 408                 Some(vstruct.fields_stripped)
 409             },
 410             _ => None,
 411         }
 412     }
 413
 414     pub fn stability_class(&self) -> Option<String> {
 415         self.stability.as_ref().and_then(|ref s| {
 416             let mut classes = Vec::with_capacity(2);
 417
 418             if s.level == stability::Unstable {
 419                 classes.push("unstable");
 420             }
 421
 422             if !s.deprecated_since.is_empty() {
 423                 classes.push("deprecated");
 424             }
 425
 426             if classes.len() != 0 {
 427                 Some(classes.join(" "))
 428             } else {
 429                 None
 430             }
 431         })
 432     }
 433
 434     pub fn stable_since(&self) -> Option<&str> {
 435         self.stability.as_ref().map(|s| &s.since[..])
 436     }
 437
 438     /// Returns a documentation-level item type from the item.
 439     pub fn type_(&self) -> ItemType {
 440         ItemType::from(self)
 441     }
 442 }
 443
 444 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
 445 pub enum ItemEnum {
 446     ExternCrateItem(String, Option<String>),
 447     ImportItem(Import),
 448     StructItem(Struct),
 449     UnionItem(Union),
 450     EnumItem(Enum),
 451     FunctionItem(Function),
 452     ModuleItem(Module),
 453     TypedefItem(Typedef, bool /* is associated type */),
 454     StaticItem(Static),
 455     ConstantItem(Constant),
 456     TraitItem(Trait),
 457     ImplItem(Impl),
 458     /// A method signature only. Used for required methods in traits (ie,
 459     /// non-default-methods).
 460     TyMethodItem(TyMethod),
 461     /// A method with a body.
 462     MethodItem(Method),
 463     StructFieldItem(Type),
 464     VariantItem(Variant),
 465     /// `fn`s from an extern block
 466     ForeignFunctionItem(Function),
 467     /// `static`s from an extern block
 468     ForeignStaticItem(Static),
 469     /// `type`s from an extern block
 470     ForeignTypeItem,
 471     MacroItem(Macro),
 472     PrimitiveItem(PrimitiveType),
 473     AssociatedConstItem(Type, Option<String>),
 474     AssociatedTypeItem(Vec<TyParamBound>, Option<Type>),
 475     /// An item that has been stripped by a rustdoc pass
 476     StrippedItem(Box<ItemEnum>),
 477 }
 478
 479 impl ItemEnum {
 480     pub fn generics(&self) -> Option<&Generics> {
 481         Some(match *self {
 482             ItemEnum::StructItem(ref s) => &s.generics,
 483             ItemEnum::EnumItem(ref e) => &e.generics,
 484             ItemEnum::FunctionItem(ref f) => &f.generics,
 485             ItemEnum::TypedefItem(ref t, _) => &t.generics,
 486             ItemEnum::TraitItem(ref t) => &t.generics,
 487             ItemEnum::ImplItem(ref i) => &i.generics,
 488             ItemEnum::TyMethodItem(ref i) => &i.generics,
 489             ItemEnum::MethodItem(ref i) => &i.generics,
 490             ItemEnum::ForeignFunctionItem(ref f) => &f.generics,
 491             _ => return None,
 492         })
 493     }
 494 }
 495
 496 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
 497 pub struct Module {
 498     pub items: Vec<Item>,
 499     pub is_crate: bool,
 500 }
 501
 502 impl Clean<Item> for doctree::Module {
 503     fn clean(&self, cx: &DocContext) -> Item {
 504         let name = if self.name.is_some() {
 505             self.name.unwrap().clean(cx)
 506         } else {
 507             "".to_string()
 508         };
 509
 510         // maintain a stack of mod ids, for doc comment path resolution
 511         // but we also need to resolve the module's own docs based on whether its docs were written
 512         // inside or outside the module, so check for that
 513         let attrs = if self.attrs.iter()
 514                                  .filter(|a| a.check_name("doc"))
 515                                  .next()
 516                                  .map_or(true, |a| a.style == AttrStyle::Inner) {
 517             // inner doc comment, use the module's own scope for resolution
 518             cx.mod_ids.borrow_mut().push(self.id);
 519             self.attrs.clean(cx)
 520         } else {
 521             // outer doc comment, use its parent's scope
 522             let attrs = self.attrs.clean(cx);
 523             cx.mod_ids.borrow_mut().push(self.id);
 524             attrs
 525         };
 526
 527         let mut items: Vec<Item> = vec![];
 528         items.extend(self.extern_crates.iter().map(|x| x.clean(cx)));
 529         items.extend(self.imports.iter().flat_map(|x| x.clean(cx)));
 530         items.extend(self.structs.iter().flat_map(|x| x.clean(cx)));
 531         items.extend(self.unions.iter().flat_map(|x| x.clean(cx)));
 532         items.extend(self.enums.iter().flat_map(|x| x.clean(cx)));
 533         items.extend(self.fns.iter().map(|x| x.clean(cx)));
 534         items.extend(self.foreigns.iter().flat_map(|x| x.clean(cx)));
 535         items.extend(self.mods.iter().map(|x| x.clean(cx)));
 536         items.extend(self.typedefs.iter().map(|x| x.clean(cx)));
 537         items.extend(self.statics.iter().map(|x| x.clean(cx)));
 538         items.extend(self.constants.iter().map(|x| x.clean(cx)));
 539         items.extend(self.traits.iter().map(|x| x.clean(cx)));
 540         items.extend(self.impls.iter().flat_map(|x| x.clean(cx)));
 541         items.extend(self.macros.iter().map(|x| x.clean(cx)));
 542
 543         cx.mod_ids.borrow_mut().pop();
 544
 545         // determine if we should display the inner contents or
 546         // the outer `mod` item for the source code.
 547         let whence = {
 548             let cm = cx.sess().codemap();
 549             let outer = cm.lookup_char_pos(self.where_outer.lo());
 550             let inner = cm.lookup_char_pos(self.where_inner.lo());
 551             if outer.file.start_pos == inner.file.start_pos {
 552                 // mod foo { ... }
 553                 self.where_outer
 554             } else {
 555                 // mod foo; (and a separate FileMap for the contents)
 556                 self.where_inner
 557             }
 558         };
 559
 560         Item {
 561             name: Some(name),
 562             attrs,
 563             source: whence.clean(cx),
 564             visibility: self.vis.clean(cx),
 565             stability: self.stab.clean(cx),
 566             deprecation: self.depr.clean(cx),
 567             def_id: cx.tcx.hir.local_def_id(self.id),
 568             inner: ModuleItem(Module {
 569                is_crate: self.is_crate,
 570                items,
 571             })
 572         }
 573     }
 574 }
 575
 576 pub struct ListAttributesIter<'a> {
 577     attrs: slice::Iter<'a, ast::Attribute>,
 578     current_list: vec::IntoIter<ast::NestedMetaItem>,
 579     name: &'a str
 580 }
 581
 582 impl<'a> Iterator for ListAttributesIter<'a> {
 583     type Item = ast::NestedMetaItem;
 584
 585     fn next(&mut self) -> Option<Self::Item> {
 586         if let Some(nested) = self.current_list.next() {
 587             return Some(nested);
 588         }
 589
 590         for attr in &mut self.attrs {
 591             if let Some(list) = attr.meta_item_list() {
 592                 if attr.check_name(self.name) {
 593                     self.current_list = list.into_iter();
 594                     if let Some(nested) = self.current_list.next() {
 595                         return Some(nested);
 596                     }
 597                 }
 598             }
 599         }
 600
 601         None
 602     }
 603
 604     fn size_hint(&self) -> (usize, Option<usize>) {
 605         let lower = self.current_list.len();
 606         (lower, None)
 607     }
 608 }
 609
 610 pub trait AttributesExt {
 611     /// Finds an attribute as List and returns the list of attributes nested inside.
 612     fn lists<'a>(&'a self, name: &'a str) -> ListAttributesIter<'a>;
 613 }
 614
 615 impl AttributesExt for [ast::Attribute] {
 616     fn lists<'a>(&'a self, name: &'a str) -> ListAttributesIter<'a> {
 617         ListAttributesIter {
 618             attrs: self.iter(),
 619             current_list: Vec::new().into_iter(),
 620             name,
 621         }
 622     }
 623 }
 624
 625 pub trait NestedAttributesExt {
 626     /// Returns whether the attribute list contains a specific `Word`
 627     fn has_word(self, word: &str) -> bool;
 628 }
 629
 630 impl<I: IntoIterator<Item=ast::NestedMetaItem>> NestedAttributesExt for I {
 631     fn has_word(self, word: &str) -> bool {
 632         self.into_iter().any(|attr| attr.is_word() && attr.check_name(word))
 633     }
 634 }
 635
 636 /// A portion of documentation, extracted from a `#[doc]` attribute.
 637 ///
 638 /// Each variant contains the line number within the complete doc-comment where the fragment
 639 /// starts, as well as the Span where the corresponding doc comment or attribute is located.
 640 ///
 641 /// Included files are kept separate from inline doc comments so that proper line-number
 642 /// information can be given when a doctest fails. Sugared doc comments and "raw" doc comments are
 643 /// kept separate because of issue #42760.
 644 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Debug, Hash)]
 645 pub enum DocFragment {
 646     // FIXME #44229 (misdreavus): sugared and raw doc comments can be brought back together once
 647     // hoedown is completely removed from rustdoc.
 648     /// A doc fragment created from a `///` or `//!` doc comment.
 649     SugaredDoc(usize, syntax_pos::Span, String),
 650     /// A doc fragment created from a "raw" `#[doc=""]` attribute.
 651     RawDoc(usize, syntax_pos::Span, String),
 652     /// A doc fragment created from a `#[doc(include="filename")]` attribute. Contains both the
 653     /// given filename and the file contents.
 654     Include(usize, syntax_pos::Span, String, String),
 655 }
 656
 657 impl DocFragment {
 658     pub fn as_str(&self) -> &str {
 659         match *self {
 660             DocFragment::SugaredDoc(_, _, ref s) => &s[..],
 661             DocFragment::RawDoc(_, _, ref s) => &s[..],
 662             DocFragment::Include(_, _, _, ref s) => &s[..],
 663         }
 664     }
 665
 666     pub fn span(&self) -> syntax_pos::Span {
 667         match *self {
 668             DocFragment::SugaredDoc(_, span, _) |
 669                 DocFragment::RawDoc(_, span, _) |
 670                 DocFragment::Include(_, span, _, _) => span,
 671         }
 672     }
 673 }
 674
 675 impl<'a> FromIterator<&'a DocFragment> for String {
 676     fn from_iter<T>(iter: T) -> Self
 677     where
 678         T: IntoIterator<Item = &'a DocFragment>
 679     {
 680         iter.into_iter().fold(String::new(), |mut acc, frag| {
 681             if !acc.is_empty() {
 682                 acc.push('\n');
 683             }
 684             match *frag {
 685                 DocFragment::SugaredDoc(_, _, ref docs)
 686                     | DocFragment::RawDoc(_, _, ref docs)
 687                     | DocFragment::Include(_, _, _, ref docs) =>
 688                     acc.push_str(docs),
 689             }
 690
 691             acc
 692         })
 693     }
 694 }
 695
 696 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Debug, Default, Hash)]
 697 pub struct Attributes {
 698     pub doc_strings: Vec<DocFragment>,
 699     pub other_attrs: Vec<ast::Attribute>,
 700     pub cfg: Option<Rc<Cfg>>,
 701     pub span: Option<syntax_pos::Span>,
 702     /// map from Rust paths to resolved defs and potential URL fragments
 703     pub links: Vec<(String, Option<DefId>, Option<String>)>,
 704 }
 705
 706 impl Attributes {
 707     /// Extracts the content from an attribute `#[doc(cfg(content))]`.
 708     fn extract_cfg(mi: &ast::MetaItem) -> Option<&ast::MetaItem> {
 709         use syntax::ast::NestedMetaItemKind::MetaItem;
 710
 711         if let ast::MetaItemKind::List(ref nmis) = mi.node {
 712             if nmis.len() == 1 {
 713                 if let MetaItem(ref cfg_mi) = nmis[0].node {
 714                     if cfg_mi.check_name("cfg") {
 715                         if let ast::MetaItemKind::List(ref cfg_nmis) = cfg_mi.node {
 716                             if cfg_nmis.len() == 1 {
 717                                 if let MetaItem(ref content_mi) = cfg_nmis[0].node {
 718                                     return Some(content_mi);
 719                                 }
 720                             }
 721                         }
 722                     }
 723                 }
 724             }
 725         }
 726
 727         None
 728     }
 729
 730     /// Reads a `MetaItem` from within an attribute, looks for whether it is a
 731     /// `#[doc(include="file")]`, and returns the filename and contents of the file as loaded from
 732     /// its expansion.
 733     fn extract_include(mi: &ast::MetaItem)
 734         -> Option<(String, String)>
 735     {
 736         mi.meta_item_list().and_then(|list| {
 737             for meta in list {
 738                 if meta.check_name("include") {
 739                     // the actual compiled `#[doc(include="filename")]` gets expanded to
 740                     // `#[doc(include(file="filename", contents="file contents")]` so we need to
 741                     // look for that instead
 742                     return meta.meta_item_list().and_then(|list| {
 743                         let mut filename: Option<String> = None;
 744                         let mut contents: Option<String> = None;
 745
 746                         for it in list {
 747                             if it.check_name("file") {
 748                                 if let Some(name) = it.value_str() {
 749                                     filename = Some(name.to_string());
 750                                 }
 751                             } else if it.check_name("contents") {
 752                                 if let Some(docs) = it.value_str() {
 753                                     contents = Some(docs.to_string());
 754                                 }
 755                             }
 756                         }
 757
 758                         if let (Some(filename), Some(contents)) = (filename, contents) {
 759                             Some((filename, contents))
 760                         } else {
 761                             None
 762                         }
 763                     });
 764                 }
 765             }
 766
 767             None
 768         })
 769     }
 770
 771     pub fn has_doc_flag(&self, flag: &str) -> bool {
 772         for attr in &self.other_attrs {
 773             if !attr.check_name("doc") { continue; }
 774
 775             if let Some(items) = attr.meta_item_list() {
 776                 if items.iter().filter_map(|i| i.meta_item()).any(|it| it.check_name(flag)) {
 777                     return true;
 778                 }
 779             }
 780         }
 781
 782         false
 783     }
 784
 785     pub fn from_ast(diagnostic: &::errors::Handler,
 786                     attrs: &[ast::Attribute]) -> Attributes {
 787         let mut doc_strings = vec![];
 788         let mut sp = None;
 789         let mut cfg = Cfg::True;
 790         let mut doc_line = 0;
 791
 792         let other_attrs = attrs.iter().filter_map(|attr| {
 793             attr.with_desugared_doc(|attr| {
 794                 if attr.check_name("doc") {
 795                     if let Some(mi) = attr.meta() {
 796                         if let Some(value) = mi.value_str() {
 797                             // Extracted #[doc = "..."]
 798                             let value = value.to_string();
 799                             let line = doc_line;
 800                             doc_line += value.lines().count();
 801
 802                             if attr.is_sugared_doc {
 803                                 doc_strings.push(DocFragment::SugaredDoc(line, attr.span, value));
 804                             } else {
 805                                 doc_strings.push(DocFragment::RawDoc(line, attr.span, value));
 806                             }
 807
 808                             if sp.is_none() {
 809                                 sp = Some(attr.span);
 810                             }
 811                             return None;
 812                         } else if let Some(cfg_mi) = Attributes::extract_cfg(&mi) {
 813                             // Extracted #[doc(cfg(...))]
 814                             match Cfg::parse(cfg_mi) {
 815                                 Ok(new_cfg) => cfg &= new_cfg,
 816                                 Err(e) => diagnostic.span_err(e.span, e.msg),
 817                             }
 818                             return None;
 819                         } else if let Some((filename, contents)) = Attributes::extract_include(&mi)
 820                         {
 821                             let line = doc_line;
 822                             doc_line += contents.lines().count();
 823                             doc_strings.push(DocFragment::Include(line,
 824                                                                   attr.span,
 825                                                                   filename,
 826                                                                   contents));
 827                         }
 828                     }
 829                 }
 830                 Some(attr.clone())
 831             })
 832         }).collect();
 833
 834         // treat #[target_feature(enable = "feat")] attributes as if they were
 835         // #[doc(cfg(target_feature = "feat"))] attributes as well
 836         for attr in attrs.lists("target_feature") {
 837             if attr.check_name("enable") {
 838                 if let Some(feat) = attr.value_str() {
 839                     let meta = attr::mk_name_value_item_str(Ident::from_str("target_feature"),
 840                                                             dummy_spanned(feat));
 841                     if let Ok(feat_cfg) = Cfg::parse(&meta) {
 842                         cfg &= feat_cfg;
 843                     }
 844                 }
 845             }
 846         }
 847
 848         Attributes {
 849             doc_strings,
 850             other_attrs,
 851             cfg: if cfg == Cfg::True { None } else { Some(Rc::new(cfg)) },
 852             span: sp,
 853             links: vec![],
 854         }
 855     }
 856
 857     /// Finds the `doc` attribute as a NameValue and returns the corresponding
 858     /// value found.
 859     pub fn doc_value<'a>(&'a self) -> Option<&'a str> {
 860         self.doc_strings.first().map(|s| s.as_str())
 861     }
 862
 863     /// Finds all `doc` attributes as NameValues and returns their corresponding values, joined
 864     /// with newlines.
 865     pub fn collapsed_doc_value(&self) -> Option<String> {
 866         if !self.doc_strings.is_empty() {
 867             Some(self.doc_strings.iter().collect())
 868         } else {
 869             None
 870         }
 871     }
 872
 873     /// Get links as a vector
 874     ///
 875     /// Cache must be populated before call
 876     pub fn links(&self, krate: &CrateNum) -> Vec<(String, String)> {
 877         use html::format::href;
 878         self.links.iter().filter_map(|&(ref s, did, ref fragment)| {
 879             match did {
 880                 Some(did) => {
 881                     if let Some((mut href, ..)) = href(did) {
 882                         if let Some(ref fragment) = *fragment {
 883                             href.push_str("#");
 884                             href.push_str(fragment);
 885                         }
 886                         Some((s.clone(), href))
 887                     } else {
 888                         None
 889                     }
 890                 }
 891                 None => {
 892                     if let Some(ref fragment) = *fragment {
 893                         let cache = cache();
 894                         let url = match cache.extern_locations.get(krate) {
 895                             Some(&(_, ref src, ExternalLocation::Local)) =>
 896                                 src.to_str().expect("invalid file path"),
 897                             Some(&(_, _, ExternalLocation::Remote(ref s))) => s,
 898                             Some(&(_, _, ExternalLocation::Unknown)) | None =>
 899                                 "https://doc.rust-lang.org/nightly",
 900                         };
 901                         // This is a primitive so the url is done "by hand".
 902                         Some((s.clone(),
 903                               format!("{}{}std/primitive.{}.html",
 904                                       url,
 905                                       if !url.ends_with('/') { "/" } else { "" },
 906                                       fragment)))
 907                     } else {
 908                         panic!("This isn't a primitive?!");
 909                     }
 910                 }
 911             }
 912         }).collect()
 913     }
 914 }
 915
 916 impl AttributesExt for Attributes {
 917     fn lists<'a>(&'a self, name: &'a str) -> ListAttributesIter<'a> {
 918         self.other_attrs.lists(name)
 919     }
 920 }
 921
 922 /// Given a def, returns its name and disambiguator
 923 /// for a value namespace
 924 ///
 925 /// Returns None for things which cannot be ambiguous since
 926 /// they exist in both namespaces (structs and modules)
 927 fn value_ns_kind(def: Def, path_str: &str) -> Option<(&'static str, String)> {
 928     match def {
 929         // structs, variants, and mods exist in both namespaces. skip them
 930         Def::StructCtor(..) | Def::Mod(..) | Def::Variant(..) | Def::VariantCtor(..) => None,
 931         Def::Fn(..)
 932             => Some(("function", format!("{}()", path_str))),
 933         Def::Method(..)
 934             => Some(("method", format!("{}()", path_str))),
 935         Def::Const(..)
 936             => Some(("const", format!("const@{}", path_str))),
 937         Def::Static(..)
 938             => Some(("static", format!("static@{}", path_str))),
 939         _ => Some(("value", format!("value@{}", path_str))),
 940     }
 941 }
 942
 943 /// Given a def, returns its name, the article to be used, and a disambiguator
 944 /// for the type namespace
 945 fn type_ns_kind(def: Def, path_str: &str) -> (&'static str, &'static str, String) {
 946     let (kind, article) = match def {
 947         // we can still have non-tuple structs
 948         Def::Struct(..) => ("struct", "a"),
 949         Def::Enum(..) => ("enum", "an"),
 950         Def::Trait(..) => ("trait", "a"),
 951         Def::Union(..) => ("union", "a"),
 952         _ => ("type", "a"),
 953     };
 954     (kind, article, format!("{}@{}", kind, path_str))
 955 }
 956
 957 fn ambiguity_error(cx: &DocContext, attrs: &Attributes,
 958                    path_str: &str,
 959                    article1: &str, kind1: &str, disambig1: &str,
 960                    article2: &str, kind2: &str, disambig2: &str) {
 961     let sp = attrs.doc_strings.first()
 962                   .map_or(DUMMY_SP, |a| a.span());
 963     cx.sess()
 964       .struct_span_warn(sp,
 965                         &format!("`{}` is both {} {} and {} {}",
 966                                  path_str, article1, kind1,
 967                                  article2, kind2))
 968       .help(&format!("try `{}` if you want to select the {}, \
 969                       or `{}` if you want to \
 970                       select the {}",
 971                       disambig1, kind1, disambig2,
 972                       kind2))
 973       .emit();
 974 }
 975
 976 /// Given an enum variant's def, return the def of its enum and the associated fragment
 977 fn handle_variant(cx: &DocContext, def: Def) -> Result<(Def, Option<String>), ()> {
 978     use rustc::ty::DefIdTree;
 979
 980     let parent = if let Some(parent) = cx.tcx.parent(def.def_id()) {
 981         parent
 982     } else {
 983         return Err(())
 984     };
 985     let parent_def = Def::Enum(parent);
 986     let variant = cx.tcx.expect_variant_def(def);
 987     Ok((parent_def, Some(format!("{}.v", variant.name))))
 988 }
 989
 990 const PRIMITIVES: &[(&str, Def)] = &[
 991     ("u8",    Def::PrimTy(hir::PrimTy::TyUint(syntax::ast::UintTy::U8))),
 992     ("u16",   Def::PrimTy(hir::PrimTy::TyUint(syntax::ast::UintTy::U16))),
 993     ("u32",   Def::PrimTy(hir::PrimTy::TyUint(syntax::ast::UintTy::U32))),
 994     ("u64",   Def::PrimTy(hir::PrimTy::TyUint(syntax::ast::UintTy::U64))),
 995     ("u128",  Def::PrimTy(hir::PrimTy::TyUint(syntax::ast::UintTy::U128))),
 996     ("usize", Def::PrimTy(hir::PrimTy::TyUint(syntax::ast::UintTy::Usize))),
 997     ("i8",    Def::PrimTy(hir::PrimTy::TyInt(syntax::ast::IntTy::I8))),
 998     ("i16",   Def::PrimTy(hir::PrimTy::TyInt(syntax::ast::IntTy::I16))),
 999     ("i32",   Def::PrimTy(hir::PrimTy::TyInt(syntax::ast::IntTy::I32))),
1000     ("i64",   Def::PrimTy(hir::PrimTy::TyInt(syntax::ast::IntTy::I64))),
1001     ("i128",  Def::PrimTy(hir::PrimTy::TyInt(syntax::ast::IntTy::I128))),
1002     ("isize", Def::PrimTy(hir::PrimTy::TyInt(syntax::ast::IntTy::Isize))),
1003     ("f32",   Def::PrimTy(hir::PrimTy::TyFloat(syntax::ast::FloatTy::F32))),
1004     ("f64",   Def::PrimTy(hir::PrimTy::TyFloat(syntax::ast::FloatTy::F64))),
1005     ("str",   Def::PrimTy(hir::PrimTy::TyStr)),
1006     ("bool",  Def::PrimTy(hir::PrimTy::TyBool)),
1007     ("char",  Def::PrimTy(hir::PrimTy::TyChar)),
1008 ];
1009
1010 fn is_primitive(path_str: &str, is_val: bool) -> Option<Def> {
1011     if is_val {
1012         None
1013     } else {
1014         PRIMITIVES.iter().find(|x| x.0 == path_str).map(|x| x.1)
1015     }
1016 }
1017
1018 /// Resolve a given string as a path, along with whether or not it is
1019 /// in the value namespace. Also returns an optional URL fragment in the case
1020 /// of variants and methods
1021 fn resolve(cx: &DocContext, path_str: &str, is_val: bool) -> Result<(Def, Option<String>), ()> {
1022     // In case we're in a module, try to resolve the relative
1023     // path
1024     if let Some(id) = cx.mod_ids.borrow().last() {
1025         let result = cx.resolver.borrow_mut()
1026                                 .with_scope(*id,
1027             |resolver| {
1028                 resolver.resolve_str_path_error(DUMMY_SP,
1029                                                 &path_str, is_val)
1030         });
1031
1032         if let Ok(result) = result {
1033             // In case this is a trait item, skip the
1034             // early return and try looking for the trait
1035             let value = match result.def {
1036                 Def::Method(_) | Def::AssociatedConst(_) => true,
1037                 Def::AssociatedTy(_)  => false,
1038                 Def::Variant(_) => return handle_variant(cx, result.def),
1039                 // not a trait item, just return what we found
1040                 _ => return Ok((result.def, None))
1041             };
1042
1043             if value != is_val {
1044                 return Err(())
1045             }
1046         } else if let Some(prim) = is_primitive(path_str, is_val) {
1047             return Ok((prim, Some(path_str.to_owned())))
1048         } else {
1049             // If resolution failed, it may still be a method
1050             // because methods are not handled by the resolver
1051             // If so, bail when we're not looking for a value
1052             if !is_val {
1053                 return Err(())
1054             }
1055         }
1056
1057         // Try looking for methods and associated items
1058         let mut split = path_str.rsplitn(2, "::");
1059         let mut item_name = if let Some(first) = split.next() {
1060             first
1061         } else {
1062             return Err(())
1063         };
1064
1065         let mut path = if let Some(second) = split.next() {
1066             second
1067         } else {
1068             return Err(())
1069         };
1070
1071         let ty = cx.resolver.borrow_mut()
1072                             .with_scope(*id,
1073             |resolver| {
1074                 resolver.resolve_str_path_error(DUMMY_SP, &path, false)
1075         })?;
1076         match ty.def {
1077             Def::Struct(did) | Def::Union(did) | Def::Enum(did) | Def::TyAlias(did) => {
1078                 let item = cx.tcx.inherent_impls(did).iter()
1079                                  .flat_map(|imp| cx.tcx.associated_items(*imp))
1080                                  .find(|item| item.name == item_name);
1081                 if let Some(item) = item {
1082                     let out = match item.kind {
1083                         ty::AssociatedKind::Method if is_val => "method",
1084                         ty::AssociatedKind::Const if is_val => "associatedconstant",
1085                         _ => return Err(())
1086                     };
1087                     Ok((ty.def, Some(format!("{}.{}", out, item_name))))
1088                 } else {
1089                     let is_enum = match ty.def {
1090                         Def::Enum(_) => true,
1091                         _ => false,
1092                     };
1093                     let elem = if is_enum {
1094                         cx.tcx.adt_def(did).all_fields().find(|item| item.name == item_name)
1095                     } else {
1096                         cx.tcx.adt_def(did)
1097                               .non_enum_variant()
1098                               .fields
1099                               .iter()
1100                               .find(|item| item.name == item_name)
1101                     };
1102                     if let Some(item) = elem {
1103                         Ok((ty.def,
1104                             Some(format!("{}.{}",
1105                                          if is_enum { "variant" } else { "structfield" },
1106                                          item.name))))
1107                     } else {
1108                         Err(())
1109                     }
1110                 }
1111             }
1112             Def::Trait(did) => {
1113                 let item = cx.tcx.associated_item_def_ids(did).iter()
1114                              .map(|item| cx.tcx.associated_item(*item))
1115                              .find(|item| item.name == item_name);
1116                 if let Some(item) = item {
1117                     let kind = match item.kind {
1118                         ty::AssociatedKind::Const if is_val => "associatedconstant",
1119                         ty::AssociatedKind::Type if !is_val => "associatedtype",
1120                         ty::AssociatedKind::Method if is_val => {
1121                             if item.defaultness.has_value() {
1122                                 "method"
1123                             } else {
1124                                 "tymethod"
1125                             }
1126                         }
1127                         _ => return Err(())
1128                     };
1129
1130                     Ok((ty.def, Some(format!("{}.{}", kind, item_name))))
1131                 } else {
1132                     Err(())
1133                 }
1134             }
1135             _ => Err(())
1136         }
1137     } else {
1138         Err(())
1139     }
1140 }
1141
1142 /// Resolve a string as a macro
1143 fn macro_resolve(cx: &DocContext, path_str: &str) -> Option<Def> {
1144     use syntax::ext::base::{MacroKind, SyntaxExtension};
1145     use syntax::ext::hygiene::Mark;
1146     let segment = ast::PathSegment::from_ident(Ident::from_str(path_str));
1147     let path = ast::Path { segments: vec![segment], span: DUMMY_SP };
1148     let mut resolver = cx.resolver.borrow_mut();
1149     let mark = Mark::root();
1150     let res = resolver
1151         .resolve_macro_to_def_inner(mark, &path, MacroKind::Bang, false);
1152     if let Ok(def) = res {
1153         if let SyntaxExtension::DeclMacro(..) = *resolver.get_macro(def) {
1154             Some(def)
1155         } else {
1156             None
1157         }
1158     } else if let Some(def) = resolver.all_macros.get(&Symbol::intern(path_str)) {
1159         Some(*def)
1160     } else {
1161         None
1162     }
1163 }
1164
1165 #[derive(Debug)]
1166 enum PathKind {
1167     /// can be either value or type, not a macro
1168     Unknown,
1169     /// macro
1170     Macro,
1171     /// values, functions, consts, statics, everything in the value namespace
1172     Value,
1173     /// types, traits, everything in the type namespace
1174     Type,
1175 }
1176
1177 fn resolution_failure(cx: &DocContext, path_str: &str) {
1178     cx.sess().warn(&format!("[{}] cannot be resolved, ignoring it...", path_str));
1179 }
1180
1181 impl Clean<Attributes> for [ast::Attribute] {
1182     fn clean(&self, cx: &DocContext) -> Attributes {
1183         let mut attrs = Attributes::from_ast(cx.sess().diagnostic(), self);
1184
1185         if UnstableFeatures::from_environment().is_nightly_build() {
1186             let dox = attrs.collapsed_doc_value().unwrap_or_else(String::new);
1187             for ori_link in markdown_links(&dox) {
1188                 // bail early for real links
1189                 if ori_link.contains('/') {
1190                     continue;
1191                 }
1192                 let link = ori_link.replace("`", "");
1193                 let (def, fragment) = {
1194                     let mut kind = PathKind::Unknown;
1195                     let path_str = if let Some(prefix) =
1196                         ["struct@", "enum@", "type@",
1197                          "trait@", "union@"].iter()
1198                                           .find(|p| link.starts_with(**p)) {
1199                         kind = PathKind::Type;
1200                         link.trim_left_matches(prefix)
1201                     } else if let Some(prefix) =
1202                         ["const@", "static@",
1203                          "value@", "function@", "mod@",
1204                          "fn@", "module@", "method@"]
1205                             .iter().find(|p| link.starts_with(**p)) {
1206                         kind = PathKind::Value;
1207                         link.trim_left_matches(prefix)
1208                     } else if link.ends_with("()") {
1209                         kind = PathKind::Value;
1210                         link.trim_right_matches("()")
1211                     } else if link.starts_with("macro@") {
1212                         kind = PathKind::Macro;
1213                         link.trim_left_matches("macro@")
1214                     } else if link.ends_with('!') {
1215                         kind = PathKind::Macro;
1216                         link.trim_right_matches('!')
1217                     } else {
1218                         &link[..]
1219                     }.trim();
1220
1221                     if path_str.contains(|ch: char| !(ch.is_alphanumeric() ||
1222                                                       ch == ':' || ch == '_')) {
1223                         continue;
1224                     }
1225
1226                     match kind {
1227                         PathKind::Value => {
1228                             if let Ok(def) = resolve(cx, path_str, true) {
1229                                 def
1230                             } else {
1231                                 resolution_failure(cx, path_str);
1232                                 // this could just be a normal link or a broken link
1233                                 // we could potentially check if something is
1234                                 // "intra-doc-link-like" and warn in that case
1235                                 continue;
1236                             }
1237                         }
1238                         PathKind::Type => {
1239                             if let Ok(def) = resolve(cx, path_str, false) {
1240                                 def
1241                             } else {
1242                                 resolution_failure(cx, path_str);
1243                                 // this could just be a normal link
1244                                 continue;
1245                             }
1246                         }
1247                         PathKind::Unknown => {
1248                             // try everything!
1249                             if let Some(macro_def) = macro_resolve(cx, path_str) {
1250                                 if let Ok(type_def) = resolve(cx, path_str, false) {
1251                                     let (type_kind, article, type_disambig)
1252                                         = type_ns_kind(type_def.0, path_str);
1253                                     ambiguity_error(cx, &attrs, path_str,
1254                                                     article, type_kind, &type_disambig,
1255                                                     "a", "macro", &format!("macro@{}", path_str));
1256                                     continue;
1257                                 } else if let Ok(value_def) = resolve(cx, path_str, true) {
1258                                     let (value_kind, value_disambig)
1259                                         = value_ns_kind(value_def.0, path_str)
1260                                             .expect("struct and mod cases should have been \
1261                                                      caught in previous branch");
1262                                     ambiguity_error(cx, &attrs, path_str,
1263                                                     "a", value_kind, &value_disambig,
1264                                                     "a", "macro", &format!("macro@{}", path_str));
1265                                 }
1266                                 (macro_def, None)
1267                             } else if let Ok(type_def) = resolve(cx, path_str, false) {
1268                                 // It is imperative we search for not-a-value first
1269                                 // Otherwise we will find struct ctors for when we are looking
1270                                 // for structs, and the link won't work.
1271                                 // if there is something in both namespaces
1272                                 if let Ok(value_def) = resolve(cx, path_str, true) {
1273                                     let kind = value_ns_kind(value_def.0, path_str);
1274                                     if let Some((value_kind, value_disambig)) = kind {
1275                                         let (type_kind, article, type_disambig)
1276                                             = type_ns_kind(type_def.0, path_str);
1277                                         ambiguity_error(cx, &attrs, path_str,
1278                                                         article, type_kind, &type_disambig,
1279                                                         "a", value_kind, &value_disambig);
1280                                         continue;
1281                                     }
1282                                 }
1283                                 type_def
1284                             } else if let Ok(value_def) = resolve(cx, path_str, true) {
1285                                 value_def
1286                             } else {
1287                                 resolution_failure(cx, path_str);
1288                                 // this could just be a normal link
1289                                 continue;
1290                             }
1291                         }
1292                         PathKind::Macro => {
1293                             if let Some(def) = macro_resolve(cx, path_str) {
1294                                 (def, None)
1295                             } else {
1296                                 resolution_failure(cx, path_str);
1297                                 continue
1298                             }
1299                         }
1300                     }
1301                 };
1302
1303                 if let Def::PrimTy(_) = def {
1304                     attrs.links.push((ori_link, None, fragment));
1305                 } else {
1306                     let id = register_def(cx, def);
1307                     attrs.links.push((ori_link, Some(id), fragment));
1308                 }
1309             }
1310
1311             cx.sess().abort_if_errors();
1312         }
1313
1314         attrs
1315     }
1316 }
1317
1318 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Debug, Hash)]
1319 pub struct TyParam {
1320     pub name: String,
1321     pub did: DefId,
1322     pub bounds: Vec<TyParamBound>,
1323     pub default: Option<Type>,
1324     pub synthetic: Option<hir::SyntheticTyParamKind>,
1325 }
1326
1327 impl Clean<TyParam> for hir::TyParam {
1328     fn clean(&self, cx: &DocContext) -> TyParam {
1329         TyParam {
1330             name: self.name.clean(cx),
1331             did: cx.tcx.hir.local_def_id(self.id),
1332             bounds: self.bounds.clean(cx),
1333             default: self.default.clean(cx),
1334             synthetic: self.synthetic,
1335         }
1336     }
1337 }
1338
1339 impl<'tcx> Clean<TyParam> for ty::TypeParameterDef {
1340     fn clean(&self, cx: &DocContext) -> TyParam {
1341         cx.renderinfo.borrow_mut().external_typarams.insert(self.def_id, self.name.clean(cx));
1342         TyParam {
1343             name: self.name.clean(cx),
1344             did: self.def_id,
1345             bounds: vec![], // these are filled in from the where-clauses
1346             default: if self.has_default {
1347                 Some(cx.tcx.type_of(self.def_id).clean(cx))
1348             } else {
1349                 None
1350             },
1351             synthetic: None,
1352         }
1353     }
1354 }
1355
1356 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Debug, Hash)]
1357 pub enum TyParamBound {
1358     RegionBound(Lifetime),
1359     TraitBound(PolyTrait, hir::TraitBoundModifier)
1360 }
1361
1362 impl TyParamBound {
1363     fn maybe_sized(cx: &DocContext) -> TyParamBound {
1364         let did = cx.tcx.require_lang_item(lang_items::SizedTraitLangItem);
1365         let empty = cx.tcx.intern_substs(&[]);
1366         let path = external_path(cx, &cx.tcx.item_name(did).as_str(),
1367             Some(did), false, vec![], empty);
1368         inline::record_extern_fqn(cx, did, TypeKind::Trait);
1369         TraitBound(PolyTrait {
1370             trait_: ResolvedPath {
1371                 path,
1372                 typarams: None,
1373                 did,
1374                 is_generic: false,
1375             },
1376             generic_params: Vec::new(),
1377         }, hir::TraitBoundModifier::Maybe)
1378     }
1379
1380     fn is_sized_bound(&self, cx: &DocContext) -> bool {
1381         use rustc::hir::TraitBoundModifier as TBM;
1382         if let TyParamBound::TraitBound(PolyTrait { ref trait_, .. }, TBM::None) = *self {
1383             if trait_.def_id() == cx.tcx.lang_items().sized_trait() {
1384                 return true;
1385             }
1386         }
1387         false
1388     }
1389
1390     fn get_poly_trait(&self) -> Option<PolyTrait> {
1391         if let TyParamBound::TraitBound(ref p, _) = *self {
1392             return Some(p.clone())
1393         }
1394         None
1395     }
1396
1397     fn get_trait_type(&self) -> Option<Type> {
1398
1399         if let TyParamBound::TraitBound(PolyTrait { ref trait_, .. }, _) = *self {
1400             return Some(trait_.clone());
1401         }
1402         None
1403     }
1404 }
1405
1406 impl Clean<TyParamBound> for hir::TyParamBound {
1407     fn clean(&self, cx: &DocContext) -> TyParamBound {
1408         match *self {
1409             hir::RegionTyParamBound(lt) => RegionBound(lt.clean(cx)),
1410             hir::TraitTyParamBound(ref t, modifier) => TraitBound(t.clean(cx), modifier),
1411         }
1412     }
1413 }
1414
1415 fn external_path_params(cx: &DocContext, trait_did: Option<DefId>, has_self: bool,
1416                         bindings: Vec<TypeBinding>, substs: &Substs) -> PathParameters {
1417     let lifetimes = substs.regions().filter_map(|v| v.clean(cx)).collect();
1418     let types = substs.types().skip(has_self as usize).collect::<Vec<_>>();
1419
1420     match trait_did {
1421         // Attempt to sugar an external path like Fn<(A, B,), C> to Fn(A, B) -> C
1422         Some(did) if cx.tcx.lang_items().fn_trait_kind(did).is_some() => {
1423             assert_eq!(types.len(), 1);
1424             let inputs = match types[0].sty {
1425                 ty::TyTuple(ref tys) => tys.iter().map(|t| t.clean(cx)).collect(),
1426                 _ => {
1427                     return PathParameters::AngleBracketed {
1428                         lifetimes,
1429                         types: types.clean(cx),
1430                         bindings,
1431                     }
1432                 }
1433             };
1434             let output = None;
1435             // FIXME(#20299) return type comes from a projection now
1436             // match types[1].sty {
1437             //     ty::TyTuple(ref v) if v.is_empty() => None, // -> ()
1438             //     _ => Some(types[1].clean(cx))
1439             // };
1440             PathParameters::Parenthesized {
1441                 inputs,
1442                 output,
1443             }
1444         },
1445         _ => {
1446             PathParameters::AngleBracketed {
1447                 lifetimes,
1448                 types: types.clean(cx),
1449                 bindings,
1450             }
1451         }
1452     }
1453 }
1454
1455 // trait_did should be set to a trait's DefId if called on a TraitRef, in order to sugar
1456 // from Fn<(A, B,), C> to Fn(A, B) -> C
1457 fn external_path(cx: &DocContext, name: &str, trait_did: Option<DefId>, has_self: bool,
1458                  bindings: Vec<TypeBinding>, substs: &Substs) -> Path {
1459     Path {
1460         global: false,
1461         def: Def::Err,
1462         segments: vec![PathSegment {
1463             name: name.to_string(),
1464             params: external_path_params(cx, trait_did, has_self, bindings, substs)
1465         }],
1466     }
1467 }
1468
1469 impl<'a, 'tcx> Clean<TyParamBound> for (&'a ty::TraitRef<'tcx>, Vec<TypeBinding>) {
1470     fn clean(&self, cx: &DocContext) -> TyParamBound {
1471         let (trait_ref, ref bounds) = *self;
1472         inline::record_extern_fqn(cx, trait_ref.def_id, TypeKind::Trait);
1473         let path = external_path(cx, &cx.tcx.item_name(trait_ref.def_id).as_str(),
1474                                  Some(trait_ref.def_id), true, bounds.clone(), trait_ref.substs);
1475
1476         debug!("ty::TraitRef\n  subst: {:?}\n", trait_ref.substs);
1477
1478         // collect any late bound regions
1479         let mut late_bounds = vec![];
1480         for ty_s in trait_ref.input_types().skip(1) {
1481             if let ty::TyTuple(ts) = ty_s.sty {
1482                 for &ty_s in ts {
1483                     if let ty::TyRef(ref reg, _, _) = ty_s.sty {
1484                         if let &ty::RegionKind::ReLateBound(..) = *reg {
1485                             debug!("  hit an ReLateBound {:?}", reg);
1486                             if let Some(lt) = reg.clean(cx) {
1487                                 late_bounds.push(GenericParam::Lifetime(lt));
1488                             }
1489                         }
1490                     }
1491                 }
1492             }
1493         }
1494
1495         TraitBound(
1496             PolyTrait {
1497                 trait_: ResolvedPath {
1498                     path,
1499                     typarams: None,
1500                     did: trait_ref.def_id,
1501                     is_generic: false,
1502                 },
1503                 generic_params: late_bounds,
1504             },
1505             hir::TraitBoundModifier::None
1506         )
1507     }
1508 }
1509
1510 impl<'tcx> Clean<TyParamBound> for ty::TraitRef<'tcx> {
1511     fn clean(&self, cx: &DocContext) -> TyParamBound {
1512         (self, vec![]).clean(cx)
1513     }
1514 }
1515
1516 impl<'tcx> Clean<Option<Vec<TyParamBound>>> for Substs<'tcx> {
1517     fn clean(&self, cx: &DocContext) -> Option<Vec<TyParamBound>> {
1518         let mut v = Vec::new();
1519         v.extend(self.regions().filter_map(|r| r.clean(cx))
1520                      .map(RegionBound));
1521         v.extend(self.types().map(|t| TraitBound(PolyTrait {
1522             trait_: t.clean(cx),
1523             generic_params: Vec::new(),
1524         }, hir::TraitBoundModifier::None)));
1525         if !v.is_empty() {Some(v)} else {None}
1526     }
1527 }
1528
1529 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Debug, Hash)]
1530 pub struct Lifetime(String);
1531
1532 impl Lifetime {
1533     pub fn get_ref<'a>(&'a self) -> &'a str {
1534         let Lifetime(ref s) = *self;
1535         let s: &'a str = s;
1536         s
1537     }
1538
1539     pub fn statik() -> Lifetime {
1540         Lifetime("'static".to_string())
1541     }
1542 }
1543
1544 impl Clean<Lifetime> for hir::Lifetime {
1545     fn clean(&self, cx: &DocContext) -> Lifetime {
1546         if self.id != ast::DUMMY_NODE_ID {
1547             let hir_id = cx.tcx.hir.node_to_hir_id(self.id);
1548             let def = cx.tcx.named_region(hir_id);
1549             match def {
1550                 Some(rl::Region::EarlyBound(_, node_id, _)) |
1551                 Some(rl::Region::LateBound(_, node_id, _)) |
1552                 Some(rl::Region::Free(_, node_id)) => {
1553                     if let Some(lt) = cx.lt_substs.borrow().get(&node_id).cloned() {
1554                         return lt;
1555                     }
1556                 }
1557                 _ => {}
1558             }
1559         }
1560         Lifetime(self.name.name().to_string())
1561     }
1562 }
1563
1564 impl Clean<Lifetime> for hir::LifetimeDef {
1565     fn clean(&self, _: &DocContext) -> Lifetime {
1566         if self.bounds.len() > 0 {
1567             let mut s = format!("{}: {}",
1568                                 self.lifetime.name.name(),
1569                                 self.bounds[0].name.name());
1570             for bound in self.bounds.iter().skip(1) {
1571                 s.push_str(&format!(" + {}", bound.name.name()));
1572             }
1573             Lifetime(s)
1574         } else {
1575             Lifetime(self.lifetime.name.name().to_string())
1576         }
1577     }
1578 }
1579
1580 impl Clean<Lifetime> for ty::RegionParameterDef {
1581     fn clean(&self, _: &DocContext) -> Lifetime {
1582         Lifetime(self.name.to_string())
1583     }
1584 }
1585
1586 impl Clean<Option<Lifetime>> for ty::RegionKind {
1587     fn clean(&self, cx: &DocContext) -> Option<Lifetime> {
1588         match *self {
1589             ty::ReStatic => Some(Lifetime::statik()),
1590             ty::ReLateBound(_, ty::BrNamed(_, name)) => Some(Lifetime(name.to_string())),
1591             ty::ReEarlyBound(ref data) => Some(Lifetime(data.name.clean(cx))),
1592
1593             ty::ReLateBound(..) |
1594             ty::ReFree(..) |
1595             ty::ReScope(..) |
1596             ty::ReVar(..) |
1597             ty::ReSkolemized(..) |
1598             ty::ReEmpty |
1599             ty::ReClosureBound(_) |
1600             ty::ReCanonical(_) |
1601             ty::ReErased => None
1602         }
1603     }
1604 }
1605
1606 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Debug, Hash)]
1607 pub enum WherePredicate {
1608     BoundPredicate { ty: Type, bounds: Vec<TyParamBound> },
1609     RegionPredicate { lifetime: Lifetime, bounds: Vec<Lifetime>},
1610     EqPredicate { lhs: Type, rhs: Type },
1611 }
1612
1613 impl Clean<WherePredicate> for hir::WherePredicate {
1614     fn clean(&self, cx: &DocContext) -> WherePredicate {
1615         match *self {
1616             hir::WherePredicate::BoundPredicate(ref wbp) => {
1617                 WherePredicate::BoundPredicate {
1618                     ty: wbp.bounded_ty.clean(cx),
1619                     bounds: wbp.bounds.clean(cx)
1620                 }
1621             }
1622
1623             hir::WherePredicate::RegionPredicate(ref wrp) => {
1624                 WherePredicate::RegionPredicate {
1625                     lifetime: wrp.lifetime.clean(cx),
1626                     bounds: wrp.bounds.clean(cx)
1627                 }
1628             }
1629
1630             hir::WherePredicate::EqPredicate(ref wrp) => {
1631                 WherePredicate::EqPredicate {
1632                     lhs: wrp.lhs_ty.clean(cx),
1633                     rhs: wrp.rhs_ty.clean(cx)
1634                 }
1635             }
1636         }
1637     }
1638 }
1639
1640 impl<'a> Clean<WherePredicate> for ty::Predicate<'a> {
1641     fn clean(&self, cx: &DocContext) -> WherePredicate {
1642         use rustc::ty::Predicate;
1643
1644         match *self {
1645             Predicate::Trait(ref pred) => pred.clean(cx),
1646             Predicate::Subtype(ref pred) => pred.clean(cx),
1647             Predicate::RegionOutlives(ref pred) => pred.clean(cx),
1648             Predicate::TypeOutlives(ref pred) => pred.clean(cx),
1649             Predicate::Projection(ref pred) => pred.clean(cx),
1650             Predicate::WellFormed(_) => panic!("not user writable"),
1651             Predicate::ObjectSafe(_) => panic!("not user writable"),
1652             Predicate::ClosureKind(..) => panic!("not user writable"),
1653             Predicate::ConstEvaluatable(..) => panic!("not user writable"),
1654         }
1655     }
1656 }
1657
1658 impl<'a> Clean<WherePredicate> for ty::TraitPredicate<'a> {
1659     fn clean(&self, cx: &DocContext) -> WherePredicate {
1660         WherePredicate::BoundPredicate {
1661             ty: self.trait_ref.self_ty().clean(cx),
1662             bounds: vec![self.trait_ref.clean(cx)]
1663         }
1664     }
1665 }
1666
1667 impl<'tcx> Clean<WherePredicate> for ty::SubtypePredicate<'tcx> {
1668     fn clean(&self, _cx: &DocContext) -> WherePredicate {
1669         panic!("subtype predicates are an internal rustc artifact \
1670                 and should not be seen by rustdoc")
1671     }
1672 }
1673
1674 impl<'tcx> Clean<WherePredicate> for ty::OutlivesPredicate<ty::Region<'tcx>, ty::Region<'tcx>> {
1675     fn clean(&self, cx: &DocContext) -> WherePredicate {
1676         let ty::OutlivesPredicate(ref a, ref b) = *self;
1677         WherePredicate::RegionPredicate {
1678             lifetime: a.clean(cx).unwrap(),
1679             bounds: vec![b.clean(cx).unwrap()]
1680         }
1681     }
1682 }
1683
1684 impl<'tcx> Clean<WherePredicate> for ty::OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>> {
1685     fn clean(&self, cx: &DocContext) -> WherePredicate {
1686         let ty::OutlivesPredicate(ref ty, ref lt) = *self;
1687
1688         WherePredicate::BoundPredicate {
1689             ty: ty.clean(cx),
1690             bounds: vec![TyParamBound::RegionBound(lt.clean(cx).unwrap())]
1691         }
1692     }
1693 }
1694
1695 impl<'tcx> Clean<WherePredicate> for ty::ProjectionPredicate<'tcx> {
1696     fn clean(&self, cx: &DocContext) -> WherePredicate {
1697         WherePredicate::EqPredicate {
1698             lhs: self.projection_ty.clean(cx),
1699             rhs: self.ty.clean(cx)
1700         }
1701     }
1702 }
1703
1704 impl<'tcx> Clean<Type> for ty::ProjectionTy<'tcx> {
1705     fn clean(&self, cx: &DocContext) -> Type {
1706         let trait_ = match self.trait_ref(cx.tcx).clean(cx) {
1707             TyParamBound::TraitBound(t, _) => t.trait_,
1708             TyParamBound::RegionBound(_) => {
1709                 panic!("cleaning a trait got a region")
1710             }
1711         };
1712         Type::QPath {
1713             name: cx.tcx.associated_item(self.item_def_id).name.clean(cx),
1714             self_type: box self.self_ty().clean(cx),
1715             trait_: box trait_
1716         }
1717     }
1718 }
1719
1720 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Debug, Hash)]
1721 pub enum GenericParam {
1722     Lifetime(Lifetime),
1723     Type(TyParam),
1724 }
1725
1726 impl GenericParam {
1727     pub fn is_synthetic_type_param(&self) -> bool {
1728         if let GenericParam::Type(ref t) = *self {
1729             t.synthetic.is_some()
1730         } else {
1731             false
1732         }
1733     }
1734 }
1735
1736 impl Clean<GenericParam> for hir::GenericParam {
1737     fn clean(&self, cx: &DocContext) -> GenericParam {
1738         match *self {
1739             hir::GenericParam::Lifetime(ref l) => GenericParam::Lifetime(l.clean(cx)),
1740             hir::GenericParam::Type(ref t) => GenericParam::Type(t.clean(cx)),
1741         }
1742     }
1743 }
1744
1745 // maybe use a Generic enum and use Vec<Generic>?
1746 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Debug, Default, Hash)]
1747 pub struct Generics {
1748     pub params: Vec<GenericParam>,
1749     pub where_predicates: Vec<WherePredicate>,
1750 }
1751
1752 impl Clean<Generics> for hir::Generics {
1753     fn clean(&self, cx: &DocContext) -> Generics {
1754         let mut params = Vec::with_capacity(self.params.len());
1755         for p in &self.params {
1756             let p = p.clean(cx);
1757             if let GenericParam::Type(ref tp) = p {
1758                 if tp.synthetic == Some(hir::SyntheticTyParamKind::ImplTrait) {
1759                     cx.impl_trait_bounds.borrow_mut().insert(tp.did, tp.bounds.clone());
1760                 }
1761             }
1762             params.push(p);
1763         }
1764         let mut g = Generics {
1765             params,
1766             where_predicates: self.where_clause.predicates.clean(cx)
1767         };
1768
1769         // Some duplicates are generated for ?Sized bounds between type params and where
1770         // predicates. The point in here is to move the bounds definitions from type params
1771         // to where predicates when such cases occur.
1772         for where_pred in &mut g.where_predicates {
1773             match *where_pred {
1774                 WherePredicate::BoundPredicate { ty: Generic(ref name), ref mut bounds } => {
1775                     if bounds.is_empty() {
1776                         for param in &mut g.params {
1777                             if let GenericParam::Type(ref mut type_param) = *param {
1778                                 if &type_param.name == name {
1779                                     mem::swap(bounds, &mut type_param.bounds);
1780                                     break
1781                                 }
1782                             }
1783                         }
1784                     }
1785                 }
1786                 _ => continue,
1787             }
1788         }
1789         g
1790     }
1791 }
1792
1793 impl<'a, 'tcx> Clean<Generics> for (&'a ty::Generics,
1794                                     &'a ty::GenericPredicates<'tcx>) {
1795     fn clean(&self, cx: &DocContext) -> Generics {
1796         use self::WherePredicate as WP;
1797
1798         let (gens, preds) = *self;
1799
1800         // Bounds in the type_params and lifetimes fields are repeated in the
1801         // predicates field (see rustc_typeck::collect::ty_generics), so remove
1802         // them.
1803         let stripped_typarams = gens.types.iter().filter_map(|tp| {
1804             if tp.name == keywords::SelfType.name().as_str() {
1805                 assert_eq!(tp.index, 0);
1806                 None
1807             } else {
1808                 Some(tp.clean(cx))
1809             }
1810         }).collect::<Vec<_>>();
1811
1812         let mut where_predicates = preds.predicates.to_vec().clean(cx);
1813
1814         // Type parameters and have a Sized bound by default unless removed with
1815         // ?Sized. Scan through the predicates and mark any type parameter with
1816         // a Sized bound, removing the bounds as we find them.
1817         //
1818         // Note that associated types also have a sized bound by default, but we
1819         // don't actually know the set of associated types right here so that's
1820         // handled in cleaning associated types
1821         let mut sized_params = FxHashSet();
1822         where_predicates.retain(|pred| {
1823             match *pred {
1824                 WP::BoundPredicate { ty: Generic(ref g), ref bounds } => {
1825                     if bounds.iter().any(|b| b.is_sized_bound(cx)) {
1826                         sized_params.insert(g.clone());
1827                         false
1828                     } else {
1829                         true
1830                     }
1831                 }
1832                 _ => true,
1833             }
1834         });
1835
1836         // Run through the type parameters again and insert a ?Sized
1837         // unbound for any we didn't find to be Sized.
1838         for tp in &stripped_typarams {
1839             if !sized_params.contains(&tp.name) {
1840                 where_predicates.push(WP::BoundPredicate {
1841                     ty: Type::Generic(tp.name.clone()),
1842                     bounds: vec![TyParamBound::maybe_sized(cx)],
1843                 })
1844             }
1845         }
1846
1847         // It would be nice to collect all of the bounds on a type and recombine
1848         // them if possible, to avoid e.g. `where T: Foo, T: Bar, T: Sized, T: 'a`
1849         // and instead see `where T: Foo + Bar + Sized + 'a`
1850
1851         Generics {
1852             params: gens.regions
1853                 .clean(cx)
1854                 .into_iter()
1855                 .map(|lp| GenericParam::Lifetime(lp))
1856                 .chain(
1857                     simplify::ty_params(stripped_typarams)
1858                         .into_iter()
1859                         .map(|tp| GenericParam::Type(tp))
1860                 )
1861                 .collect(),
1862             where_predicates: simplify::where_clauses(cx, where_predicates),
1863         }
1864     }
1865 }
1866
1867 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1868 pub struct Method {
1869     pub generics: Generics,
1870     pub unsafety: hir::Unsafety,
1871     pub constness: hir::Constness,
1872     pub decl: FnDecl,
1873     pub abi: Abi,
1874 }
1875
1876 impl<'a> Clean<Method> for (&'a hir::MethodSig, &'a hir::Generics, hir::BodyId) {
1877     fn clean(&self, cx: &DocContext) -> Method {
1878         let (generics, decl) = enter_impl_trait(cx, || {
1879             (self.1.clean(cx), (&*self.0.decl, self.2).clean(cx))
1880         });
1881         Method {
1882             decl,
1883             generics,
1884             unsafety: self.0.unsafety,
1885             constness: self.0.constness,
1886             abi: self.0.abi
1887         }
1888     }
1889 }
1890
1891 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1892 pub struct TyMethod {
1893     pub unsafety: hir::Unsafety,
1894     pub decl: FnDecl,
1895     pub generics: Generics,
1896     pub abi: Abi,
1897 }
1898
1899 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1900 pub struct Function {
1901     pub decl: FnDecl,
1902     pub generics: Generics,
1903     pub unsafety: hir::Unsafety,
1904     pub constness: hir::Constness,
1905     pub abi: Abi,
1906 }
1907
1908 impl Clean<Item> for doctree::Function {
1909     fn clean(&self, cx: &DocContext) -> Item {
1910         let (generics, decl) = enter_impl_trait(cx, || {
1911             (self.generics.clean(cx), (&self.decl, self.body).clean(cx))
1912         });
1913         Item {
1914             name: Some(self.name.clean(cx)),
1915             attrs: self.attrs.clean(cx),
1916             source: self.whence.clean(cx),
1917             visibility: self.vis.clean(cx),
1918             stability: self.stab.clean(cx),
1919             deprecation: self.depr.clean(cx),
1920             def_id: cx.tcx.hir.local_def_id(self.id),
1921             inner: FunctionItem(Function {
1922                 decl,
1923                 generics,
1924                 unsafety: self.unsafety,
1925                 constness: self.constness,
1926                 abi: self.abi,
1927             }),
1928         }
1929     }
1930 }
1931
1932 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Debug, Hash)]
1933 pub struct FnDecl {
1934     pub inputs: Arguments,
1935     pub output: FunctionRetTy,
1936     pub variadic: bool,
1937     pub attrs: Attributes,
1938 }
1939
1940 impl FnDecl {
1941     pub fn has_self(&self) -> bool {
1942         self.inputs.values.len() > 0 && self.inputs.values[0].name == "self"
1943     }
1944
1945     pub fn self_type(&self) -> Option<SelfTy> {
1946         self.inputs.values.get(0).and_then(|v| v.to_self())
1947     }
1948 }
1949
1950 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Debug, Hash)]
1951 pub struct Arguments {
1952     pub values: Vec<Argument>,
1953 }
1954
1955 impl<'a> Clean<Arguments> for (&'a [P<hir::Ty>], &'a [Spanned<ast::Name>]) {
1956     fn clean(&self, cx: &DocContext) -> Arguments {
1957         Arguments {
1958             values: self.0.iter().enumerate().map(|(i, ty)| {
1959                 let mut name = self.1.get(i).map(|n| n.node.to_string())
1960                                             .unwrap_or(String::new());
1961                 if name.is_empty() {
1962                     name = "_".to_string();
1963                 }
1964                 Argument {
1965                     name,
1966                     type_: ty.clean(cx),
1967                 }
1968             }).collect()
1969         }
1970     }
1971 }
1972
1973 impl<'a> Clean<Arguments> for (&'a [P<hir::Ty>], hir::BodyId) {
1974     fn clean(&self, cx: &DocContext) -> Arguments {
1975         let body = cx.tcx.hir.body(self.1);
1976
1977         Arguments {
1978             values: self.0.iter().enumerate().map(|(i, ty)| {
1979                 Argument {
1980                     name: name_from_pat(&body.arguments[i].pat),
1981                     type_: ty.clean(cx),
1982                 }
1983             }).collect()
1984         }
1985     }
1986 }
1987
1988 impl<'a, A: Copy> Clean<FnDecl> for (&'a hir::FnDecl, A)
1989     where (&'a [P<hir::Ty>], A): Clean<Arguments>
1990 {
1991     fn clean(&self, cx: &DocContext) -> FnDecl {
1992         FnDecl {
1993             inputs: (&self.0.inputs[..], self.1).clean(cx),
1994             output: self.0.output.clean(cx),
1995             variadic: self.0.variadic,
1996             attrs: Attributes::default()
1997         }
1998     }
1999 }
2000
2001 impl<'a, 'tcx> Clean<FnDecl> for (DefId, ty::PolyFnSig<'tcx>) {
2002     fn clean(&self, cx: &DocContext) -> FnDecl {
2003         let (did, sig) = *self;
2004         let mut names = if cx.tcx.hir.as_local_node_id(did).is_some() {
2005             vec![].into_iter()
2006         } else {
2007             cx.tcx.fn_arg_names(did).into_iter()
2008         };
2009
2010         FnDecl {
2011             output: Return(sig.skip_binder().output().clean(cx)),
2012             attrs: Attributes::default(),
2013             variadic: sig.skip_binder().variadic,
2014             inputs: Arguments {
2015                 values: sig.skip_binder().inputs().iter().map(|t| {
2016                     Argument {
2017                         type_: t.clean(cx),
2018                         name: names.next().map_or("".to_string(), |name| name.to_string()),
2019                     }
2020                 }).collect(),
2021             },
2022         }
2023     }
2024 }
2025
2026 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Debug, Hash)]
2027 pub struct Argument {
2028     pub type_: Type,
2029     pub name: String,
2030 }
2031
2032 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Debug)]
2033 pub enum SelfTy {
2034     SelfValue,
2035     SelfBorrowed(Option<Lifetime>, Mutability),
2036     SelfExplicit(Type),
2037 }
2038
2039 impl Argument {
2040     pub fn to_self(&self) -> Option<SelfTy> {
2041         if self.name != "self" {
2042             return None;
2043         }
2044         if self.type_.is_self_type() {
2045             return Some(SelfValue);
2046         }
2047         match self.type_ {
2048             BorrowedRef{ref lifetime, mutability, ref type_} if type_.is_self_type() => {
2049                 Some(SelfBorrowed(lifetime.clone(), mutability))
2050             }
2051             _ => Some(SelfExplicit(self.type_.clone()))
2052         }
2053     }
2054 }
2055
2056 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Debug, Hash)]
2057 pub enum FunctionRetTy {
2058     Return(Type),
2059     DefaultReturn,
2060 }
2061
2062 impl Clean<FunctionRetTy> for hir::FunctionRetTy {
2063     fn clean(&self, cx: &DocContext) -> FunctionRetTy {
2064         match *self {
2065             hir::Return(ref typ) => Return(typ.clean(cx)),
2066             hir::DefaultReturn(..) => DefaultReturn,
2067         }
2068     }
2069 }
2070
2071 impl GetDefId for FunctionRetTy {
2072     fn def_id(&self) -> Option<DefId> {
2073         match *self {
2074             Return(ref ty) => ty.def_id(),
2075             DefaultReturn => None,
2076         }
2077     }
2078 }
2079
2080 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
2081 pub struct Trait {
2082     pub auto: bool,
2083     pub unsafety: hir::Unsafety,
2084     pub items: Vec<Item>,
2085     pub generics: Generics,
2086     pub bounds: Vec<TyParamBound>,
2087     pub is_spotlight: bool,
2088     pub is_auto: bool,
2089 }
2090
2091 impl Clean<Item> for doctree::Trait {
2092     fn clean(&self, cx: &DocContext) -> Item {
2093         let attrs = self.attrs.clean(cx);
2094         let is_spotlight = attrs.has_doc_flag("spotlight");
2095         Item {
2096             name: Some(self.name.clean(cx)),
2097             attrs: attrs,
2098             source: self.whence.clean(cx),
2099             def_id: cx.tcx.hir.local_def_id(self.id),
2100             visibility: self.vis.clean(cx),
2101             stability: self.stab.clean(cx),
2102             deprecation: self.depr.clean(cx),
2103             inner: TraitItem(Trait {
2104                 auto: self.is_auto.clean(cx),
2105                 unsafety: self.unsafety,
2106                 items: self.items.clean(cx),
2107                 generics: self.generics.clean(cx),
2108                 bounds: self.bounds.clean(cx),
2109                 is_spotlight: is_spotlight,
2110                 is_auto: self.is_auto.clean(cx),
2111             }),
2112         }
2113     }
2114 }
2115
2116 impl Clean<bool> for hir::IsAuto {
2117     fn clean(&self, _: &DocContext) -> bool {
2118         match *self {
2119             hir::IsAuto::Yes => true,
2120             hir::IsAuto::No => false,
2121         }
2122     }
2123 }
2124
2125 impl Clean<Type> for hir::TraitRef {
2126     fn clean(&self, cx: &DocContext) -> Type {
2127         resolve_type(cx, self.path.clean(cx), self.ref_id)
2128     }
2129 }
2130
2131 impl Clean<PolyTrait> for hir::PolyTraitRef {
2132     fn clean(&self, cx: &DocContext) -> PolyTrait {
2133         PolyTrait {
2134             trait_: self.trait_ref.clean(cx),
2135             generic_params: self.bound_generic_params.clean(cx)
2136         }
2137     }
2138 }
2139
2140 impl Clean<Item> for hir::TraitItem {
2141     fn clean(&self, cx: &DocContext) -> Item {
2142         let inner = match self.node {
2143             hir::TraitItemKind::Const(ref ty, default) => {
2144                 AssociatedConstItem(ty.clean(cx),
2145                                     default.map(|e| print_const_expr(cx, e)))
2146             }
2147             hir::TraitItemKind::Method(ref sig, hir::TraitMethod::Provided(body)) => {
2148                 MethodItem((sig, &self.generics, body).clean(cx))
2149             }
2150             hir::TraitItemKind::Method(ref sig, hir::TraitMethod::Required(ref names)) => {
2151                 let (generics, decl) = enter_impl_trait(cx, || {
2152                     (self.generics.clean(cx), (&*sig.decl, &names[..]).clean(cx))
2153                 });
2154                 TyMethodItem(TyMethod {
2155                     unsafety: sig.unsafety.clone(),
2156                     decl,
2157                     generics,
2158                     abi: sig.abi
2159                 })
2160             }
2161             hir::TraitItemKind::Type(ref bounds, ref default) => {
2162                 AssociatedTypeItem(bounds.clean(cx), default.clean(cx))
2163             }
2164         };
2165         Item {
2166             name: Some(self.name.clean(cx)),
2167             attrs: self.attrs.clean(cx),
2168             source: self.span.clean(cx),
2169             def_id: cx.tcx.hir.local_def_id(self.id),
2170             visibility: None,
2171             stability: get_stability(cx, cx.tcx.hir.local_def_id(self.id)),
2172             deprecation: get_deprecation(cx, cx.tcx.hir.local_def_id(self.id)),
2173             inner,
2174         }
2175     }
2176 }
2177
2178 impl Clean<Item> for hir::ImplItem {
2179     fn clean(&self, cx: &DocContext) -> Item {
2180         let inner = match self.node {
2181             hir::ImplItemKind::Const(ref ty, expr) => {
2182                 AssociatedConstItem(ty.clean(cx),
2183                                     Some(print_const_expr(cx, expr)))
2184             }
2185             hir::ImplItemKind::Method(ref sig, body) => {
2186                 MethodItem((sig, &self.generics, body).clean(cx))
2187             }
2188             hir::ImplItemKind::Type(ref ty) => TypedefItem(Typedef {
2189                 type_: ty.clean(cx),
2190                 generics: Generics::default(),
2191             }, true),
2192         };
2193         Item {
2194             name: Some(self.name.clean(cx)),
2195             source: self.span.clean(cx),
2196             attrs: self.attrs.clean(cx),
2197             def_id: cx.tcx.hir.local_def_id(self.id),
2198             visibility: self.vis.clean(cx),
2199             stability: get_stability(cx, cx.tcx.hir.local_def_id(self.id)),
2200             deprecation: get_deprecation(cx, cx.tcx.hir.local_def_id(self.id)),
2201             inner,
2202         }
2203     }
2204 }
2205
2206 impl<'tcx> Clean<Item> for ty::AssociatedItem {
2207     fn clean(&self, cx: &DocContext) -> Item {
2208         let inner = match self.kind {
2209             ty::AssociatedKind::Const => {
2210                 let ty = cx.tcx.type_of(self.def_id);
2211                 let default = if self.defaultness.has_value() {
2212                     Some(inline::print_inlined_const(cx, self.def_id))
2213                 } else {
2214                     None
2215                 };
2216                 AssociatedConstItem(ty.clean(cx), default)
2217             }
2218             ty::AssociatedKind::Method => {
2219                 let generics = (cx.tcx.generics_of(self.def_id),
2220                                 &cx.tcx.predicates_of(self.def_id)).clean(cx);
2221                 let sig = cx.tcx.fn_sig(self.def_id);
2222                 let mut decl = (self.def_id, sig).clean(cx);
2223
2224                 if self.method_has_self_argument {
2225                     let self_ty = match self.container {
2226                         ty::ImplContainer(def_id) => {
2227                             cx.tcx.type_of(def_id)
2228                         }
2229                         ty::TraitContainer(_) => cx.tcx.mk_self_type()
2230                     };
2231                     let self_arg_ty = *sig.input(0).skip_binder();
2232                     if self_arg_ty == self_ty {
2233                         decl.inputs.values[0].type_ = Generic(String::from("Self"));
2234                     } else if let ty::TyRef(_, ty, _) = self_arg_ty.sty {
2235                         if ty == self_ty {
2236                             match decl.inputs.values[0].type_ {
2237                                 BorrowedRef{ref mut type_, ..} => {
2238                                     **type_ = Generic(String::from("Self"))
2239                                 }
2240                                 _ => unreachable!(),
2241                             }
2242                         }
2243                     }
2244                 }
2245
2246                 let provided = match self.container {
2247                     ty::ImplContainer(_) => true,
2248                     ty::TraitContainer(_) => self.defaultness.has_value()
2249                 };
2250                 if provided {
2251                     let constness = if cx.tcx.is_const_fn(self.def_id) {
2252                         hir::Constness::Const
2253                     } else {
2254                         hir::Constness::NotConst
2255                     };
2256                     MethodItem(Method {
2257                         unsafety: sig.unsafety(),
2258                         generics,
2259                         decl,
2260                         abi: sig.abi(),
2261                         constness,
2262                     })
2263                 } else {
2264                     TyMethodItem(TyMethod {
2265                         unsafety: sig.unsafety(),
2266                         generics,
2267                         decl,
2268                         abi: sig.abi(),
2269                     })
2270                 }
2271             }
2272             ty::AssociatedKind::Type => {
2273                 let my_name = self.name.clean(cx);
2274
2275                 if let ty::TraitContainer(did) = self.container {
2276                     // When loading a cross-crate associated type, the bounds for this type
2277                     // are actually located on the trait/impl itself, so we need to load
2278                     // all of the generics from there and then look for bounds that are
2279                     // applied to this associated type in question.
2280                     let predicates = cx.tcx.predicates_of(did);
2281                     let generics = (cx.tcx.generics_of(did), &predicates).clean(cx);
2282                     let mut bounds = generics.where_predicates.iter().filter_map(|pred| {
2283                         let (name, self_type, trait_, bounds) = match *pred {
2284                             WherePredicate::BoundPredicate {
2285                                 ty: QPath { ref name, ref self_type, ref trait_ },
2286                                 ref bounds
2287                             } => (name, self_type, trait_, bounds),
2288                             _ => return None,
2289                         };
2290                         if *name != my_name { return None }
2291                         match **trait_ {
2292                             ResolvedPath { did, .. } if did == self.container.id() => {}
2293                             _ => return None,
2294                         }
2295                         match **self_type {
2296                             Generic(ref s) if *s == "Self" => {}
2297                             _ => return None,
2298                         }
2299                         Some(bounds)
2300                     }).flat_map(|i| i.iter().cloned()).collect::<Vec<_>>();
2301                     // Our Sized/?Sized bound didn't get handled when creating the generics
2302                     // because we didn't actually get our whole set of bounds until just now
2303                     // (some of them may have come from the trait). If we do have a sized
2304                     // bound, we remove it, and if we don't then we add the `?Sized` bound
2305                     // at the end.
2306                     match bounds.iter().position(|b| b.is_sized_bound(cx)) {
2307                         Some(i) => { bounds.remove(i); }
2308                         None => bounds.push(TyParamBound::maybe_sized(cx)),
2309                     }
2310
2311                     let ty = if self.defaultness.has_value() {
2312                         Some(cx.tcx.type_of(self.def_id))
2313                     } else {
2314                         None
2315                     };
2316
2317                     AssociatedTypeItem(bounds, ty.clean(cx))
2318                 } else {
2319                     TypedefItem(Typedef {
2320                         type_: cx.tcx.type_of(self.def_id).clean(cx),
2321                         generics: Generics {
2322                             params: Vec::new(),
2323                             where_predicates: Vec::new(),
2324                         },
2325                     }, true)
2326                 }
2327             }
2328         };
2329
2330         let visibility = match self.container {
2331             ty::ImplContainer(_) => self.vis.clean(cx),
2332             ty::TraitContainer(_) => None,
2333         };
2334
2335         Item {
2336             name: Some(self.name.clean(cx)),
2337             visibility,
2338             stability: get_stability(cx, self.def_id),
2339             deprecation: get_deprecation(cx, self.def_id),
2340             def_id: self.def_id,
2341             attrs: inline::load_attrs(cx, self.def_id),
2342             source: cx.tcx.def_span(self.def_id).clean(cx),
2343             inner,
2344         }
2345     }
2346 }
2347
2348 /// A trait reference, which may have higher ranked lifetimes.
2349 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Debug, Hash)]
2350 pub struct PolyTrait {
2351     pub trait_: Type,
2352     pub generic_params: Vec<GenericParam>,
2353 }
2354
2355 /// A representation of a Type suitable for hyperlinking purposes. Ideally one can get the original
2356 /// type out of the AST/TyCtxt given one of these, if more information is needed. Most importantly
2357 /// it does not preserve mutability or boxes.
2358 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Debug, Hash)]
2359 pub enum Type {
2360     /// structs/enums/traits (most that'd be an hir::TyPath)
2361     ResolvedPath {
2362         path: Path,
2363         typarams: Option<Vec<TyParamBound>>,
2364         did: DefId,
2365         /// true if is a `T::Name` path for associated types
2366         is_generic: bool,
2367     },
2368     /// For parameterized types, so the consumer of the JSON don't go
2369     /// looking for types which don't exist anywhere.
2370     Generic(String),
2371     /// Primitives are the fixed-size numeric types (plus int/usize/float), char,
2372     /// arrays, slices, and tuples.
2373     Primitive(PrimitiveType),
2374     /// extern "ABI" fn
2375     BareFunction(Box<BareFunctionDecl>),
2376     Tuple(Vec<Type>),
2377     Slice(Box<Type>),
2378     Array(Box<Type>, String),
2379     Never,
2380     Unique(Box<Type>),
2381     RawPointer(Mutability, Box<Type>),
2382     BorrowedRef {
2383         lifetime: Option<Lifetime>,
2384         mutability: Mutability,
2385         type_: Box<Type>,
2386     },
2387
2388     // <Type as Trait>::Name
2389     QPath {
2390         name: String,
2391         self_type: Box<Type>,
2392         trait_: Box<Type>
2393     },
2394
2395     // _
2396     Infer,
2397
2398     // impl TraitA+TraitB
2399     ImplTrait(Vec<TyParamBound>),
2400 }
2401
2402 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Hash, Copy, Debug)]
2403 pub enum PrimitiveType {
2404     Isize, I8, I16, I32, I64, I128,
2405     Usize, U8, U16, U32, U64, U128,
2406     F32, F64,
2407     Char,
2408     Bool,
2409     Str,
2410     Slice,
2411     Array,
2412     Tuple,
2413     Unit,
2414     RawPointer,
2415     Reference,
2416     Fn,
2417     Never,
2418 }
2419
2420 #[derive(Clone, RustcEncodable, RustcDecodable, Copy, Debug)]
2421 pub enum TypeKind {
2422     Enum,
2423     Function,
2424     Module,
2425     Const,
2426     Static,
2427     Struct,
2428     Union,
2429     Trait,
2430     Variant,
2431     Typedef,
2432     Foreign,
2433     Macro,
2434 }
2435
2436 pub trait GetDefId {
2437     fn def_id(&self) -> Option<DefId>;
2438 }
2439
2440 impl<T: GetDefId> GetDefId for Option<T> {
2441     fn def_id(&self) -> Option<DefId> {
2442         self.as_ref().and_then(|d| d.def_id())
2443     }
2444 }
2445
2446 impl Type {
2447     pub fn primitive_type(&self) -> Option<PrimitiveType> {
2448         match *self {
2449             Primitive(p) | BorrowedRef { type_: box Primitive(p), ..} => Some(p),
2450             Slice(..) | BorrowedRef { type_: box Slice(..), .. } => Some(PrimitiveType::Slice),
2451             Array(..) | BorrowedRef { type_: box Array(..), .. } => Some(PrimitiveType::Array),
2452             Tuple(ref tys) => if tys.is_empty() {
2453                 Some(PrimitiveType::Unit)
2454             } else {
2455                 Some(PrimitiveType::Tuple)
2456             },
2457             RawPointer(..) => Some(PrimitiveType::RawPointer),
2458             BorrowedRef { type_: box Generic(..), .. } => Some(PrimitiveType::Reference),
2459             BareFunction(..) => Some(PrimitiveType::Fn),
2460             Never => Some(PrimitiveType::Never),
2461             _ => None,
2462         }
2463     }
2464
2465     pub fn is_generic(&self) -> bool {
2466         match *self {
2467             ResolvedPath { is_generic, .. } => is_generic,
2468             _ => false,
2469         }
2470     }
2471
2472     pub fn is_self_type(&self) -> bool {
2473         match *self {
2474             Generic(ref name) => name == "Self",
2475             _ => false
2476         }
2477     }
2478
2479     pub fn generics(&self) -> Option<&[Type]> {
2480         match *self {
2481             ResolvedPath { ref path, .. } => {
2482                 path.segments.last().and_then(|seg| {
2483                     if let PathParameters::AngleBracketed { ref types, .. } = seg.params {
2484                         Some(&**types)
2485                     } else {
2486                         None
2487                     }
2488                 })
2489             }
2490             _ => None,
2491         }
2492     }
2493 }
2494
2495 impl GetDefId for Type {
2496     fn def_id(&self) -> Option<DefId> {
2497         match *self {
2498             ResolvedPath { did, .. } => Some(did),
2499             Primitive(p) => ::html::render::cache().primitive_locations.get(&p).cloned(),
2500             BorrowedRef { type_: box Generic(..), .. } =>
2501                 Primitive(PrimitiveType::Reference).def_id(),
2502             BorrowedRef { ref type_, .. } => type_.def_id(),
2503             Tuple(ref tys) => if tys.is_empty() {
2504                 Primitive(PrimitiveType::Unit).def_id()
2505             } else {
2506                 Primitive(PrimitiveType::Tuple).def_id()
2507             },
2508             BareFunction(..) => Primitive(PrimitiveType::Fn).def_id(),
2509             Never => Primitive(PrimitiveType::Never).def_id(),
2510             Slice(..) => Primitive(PrimitiveType::Slice).def_id(),
2511             Array(..) => Primitive(PrimitiveType::Array).def_id(),
2512             RawPointer(..) => Primitive(PrimitiveType::RawPointer).def_id(),
2513             QPath { ref self_type, .. } => self_type.def_id(),
2514             _ => None,
2515         }
2516     }
2517 }
2518
2519 impl PrimitiveType {
2520     fn from_str(s: &str) -> Option<PrimitiveType> {
2521         match s {
2522             "isize" => Some(PrimitiveType::Isize),
2523             "i8" => Some(PrimitiveType::I8),
2524             "i16" => Some(PrimitiveType::I16),
2525             "i32" => Some(PrimitiveType::I32),
2526             "i64" => Some(PrimitiveType::I64),
2527             "i128" => Some(PrimitiveType::I128),
2528             "usize" => Some(PrimitiveType::Usize),
2529             "u8" => Some(PrimitiveType::U8),
2530             "u16" => Some(PrimitiveType::U16),
2531             "u32" => Some(PrimitiveType::U32),
2532             "u64" => Some(PrimitiveType::U64),
2533             "u128" => Some(PrimitiveType::U128),
2534             "bool" => Some(PrimitiveType::Bool),
2535             "char" => Some(PrimitiveType::Char),
2536             "str" => Some(PrimitiveType::Str),
2537             "f32" => Some(PrimitiveType::F32),
2538             "f64" => Some(PrimitiveType::F64),
2539             "array" => Some(PrimitiveType::Array),
2540             "slice" => Some(PrimitiveType::Slice),
2541             "tuple" => Some(PrimitiveType::Tuple),
2542             "unit" => Some(PrimitiveType::Unit),
2543             "pointer" => Some(PrimitiveType::RawPointer),
2544             "reference" => Some(PrimitiveType::Reference),
2545             "fn" => Some(PrimitiveType::Fn),
2546             "never" => Some(PrimitiveType::Never),
2547             _ => None,
2548         }
2549     }
2550
2551     pub fn as_str(&self) -> &'static str {
2552         use self::PrimitiveType::*;
2553         match *self {
2554             Isize => "isize",
2555             I8 => "i8",
2556             I16 => "i16",
2557             I32 => "i32",
2558             I64 => "i64",
2559             I128 => "i128",
2560             Usize => "usize",
2561             U8 => "u8",
2562             U16 => "u16",
2563             U32 => "u32",
2564             U64 => "u64",
2565             U128 => "u128",
2566             F32 => "f32",
2567             F64 => "f64",
2568             Str => "str",
2569             Bool => "bool",
2570             Char => "char",
2571             Array => "array",
2572             Slice => "slice",
2573             Tuple => "tuple",
2574             Unit => "unit",
2575             RawPointer => "pointer",
2576             Reference => "reference",
2577             Fn => "fn",
2578             Never => "never",
2579         }
2580     }
2581
2582     pub fn to_url_str(&self) -> &'static str {
2583         self.as_str()
2584     }
2585 }
2586
2587 impl From<ast::IntTy> for PrimitiveType {
2588     fn from(int_ty: ast::IntTy) -> PrimitiveType {
2589         match int_ty {
2590             ast::IntTy::Isize => PrimitiveType::Isize,
2591             ast::IntTy::I8 => PrimitiveType::I8,
2592             ast::IntTy::I16 => PrimitiveType::I16,
2593             ast::IntTy::I32 => PrimitiveType::I32,
2594             ast::IntTy::I64 => PrimitiveType::I64,
2595             ast::IntTy::I128 => PrimitiveType::I128,
2596         }
2597     }
2598 }
2599
2600 impl From<ast::UintTy> for PrimitiveType {
2601     fn from(uint_ty: ast::UintTy) -> PrimitiveType {
2602         match uint_ty {
2603             ast::UintTy::Usize => PrimitiveType::Usize,
2604             ast::UintTy::U8 => PrimitiveType::U8,
2605             ast::UintTy::U16 => PrimitiveType::U16,
2606             ast::UintTy::U32 => PrimitiveType::U32,
2607             ast::UintTy::U64 => PrimitiveType::U64,
2608             ast::UintTy::U128 => PrimitiveType::U128,
2609         }
2610     }
2611 }
2612
2613 impl From<ast::FloatTy> for PrimitiveType {
2614     fn from(float_ty: ast::FloatTy) -> PrimitiveType {
2615         match float_ty {
2616             ast::FloatTy::F32 => PrimitiveType::F32,
2617             ast::FloatTy::F64 => PrimitiveType::F64,
2618         }
2619     }
2620 }
2621
2622 impl Clean<Type> for hir::Ty {
2623     fn clean(&self, cx: &DocContext) -> Type {
2624         use rustc::hir::*;
2625         match self.node {
2626             TyNever => Never,
2627             TyPtr(ref m) => RawPointer(m.mutbl.clean(cx), box m.ty.clean(cx)),
2628             TyRptr(ref l, ref m) => {
2629                 let lifetime = if l.is_elided() {
2630                     None
2631                 } else {
2632                     Some(l.clean(cx))
2633                 };
2634                 BorrowedRef {lifetime: lifetime, mutability: m.mutbl.clean(cx),
2635                              type_: box m.ty.clean(cx)}
2636             }
2637             TySlice(ref ty) => Slice(box ty.clean(cx)),
2638             TyArray(ref ty, n) => {
2639                 let def_id = cx.tcx.hir.body_owner_def_id(n);
2640                 let param_env = cx.tcx.param_env(def_id);
2641                 let substs = Substs::identity_for_item(cx.tcx, def_id);
2642                 let cid = GlobalId {
2643                     instance: ty::Instance::new(def_id, substs),
2644                     promoted: None
2645                 };
2646                 let n = cx.tcx.const_eval(param_env.and(cid)).unwrap_or_else(|_| {
2647                     ty::Const::unevaluated(cx.tcx, def_id, substs, cx.tcx.types.usize)
2648                 });
2649                 let n = print_const(cx, n);
2650                 Array(box ty.clean(cx), n)
2651             },
2652             TyTup(ref tys) => Tuple(tys.clean(cx)),
2653             TyPath(hir::QPath::Resolved(None, ref path)) => {
2654                 if let Some(new_ty) = cx.ty_substs.borrow().get(&path.def).cloned() {
2655                     return new_ty;
2656                 }
2657
2658                 if let Def::TyParam(did) = path.def {
2659                     if let Some(bounds) = cx.impl_trait_bounds.borrow_mut().remove(&did) {
2660                         return ImplTrait(bounds);
2661                     }
2662                 }
2663
2664                 let mut alias = None;
2665                 if let Def::TyAlias(def_id) = path.def {
2666                     // Substitute private type aliases
2667                     if let Some(node_id) = cx.tcx.hir.as_local_node_id(def_id) {
2668                         if !cx.access_levels.borrow().is_exported(def_id) {
2669                             alias = Some(&cx.tcx.hir.expect_item(node_id).node);
2670                         }
2671                     }
2672                 };
2673
2674                 if let Some(&hir::ItemTy(ref ty, ref generics)) = alias {
2675                     let provided_params = &path.segments.last().unwrap();
2676                     let mut ty_substs = FxHashMap();
2677                     let mut lt_substs = FxHashMap();
2678                     provided_params.with_parameters(|provided_params| {
2679                         for (i, ty_param) in generics.ty_params().enumerate() {
2680                             let ty_param_def = Def::TyParam(cx.tcx.hir.local_def_id(ty_param.id));
2681                             if let Some(ty) = provided_params.types.get(i).cloned() {
2682                                 ty_substs.insert(ty_param_def, ty.into_inner().clean(cx));
2683                             } else if let Some(default) = ty_param.default.clone() {
2684                                 ty_substs.insert(ty_param_def, default.into_inner().clean(cx));
2685                             }
2686                         }
2687
2688                         for (i, lt_param) in generics.lifetimes().enumerate() {
2689                             if let Some(lt) = provided_params.lifetimes.get(i).cloned() {
2690                                 if !lt.is_elided() {
2691                                     let lt_def_id = cx.tcx.hir.local_def_id(lt_param.lifetime.id);
2692                                     lt_substs.insert(lt_def_id, lt.clean(cx));
2693                                 }
2694                             }
2695                         }
2696                     });
2697                     return cx.enter_alias(ty_substs, lt_substs, || ty.clean(cx));
2698                 }
2699                 resolve_type(cx, path.clean(cx), self.id)
2700             }
2701             TyPath(hir::QPath::Resolved(Some(ref qself), ref p)) => {
2702                 let mut segments: Vec<_> = p.segments.clone().into();
2703                 segments.pop();
2704                 let trait_path = hir::Path {
2705                     span: p.span,
2706                     def: Def::Trait(cx.tcx.associated_item(p.def.def_id()).container.id()),
2707                     segments: segments.into(),
2708                 };
2709                 Type::QPath {
2710                     name: p.segments.last().unwrap().name.clean(cx),
2711                     self_type: box qself.clean(cx),
2712                     trait_: box resolve_type(cx, trait_path.clean(cx), self.id)
2713                 }
2714             }
2715             TyPath(hir::QPath::TypeRelative(ref qself, ref segment)) => {
2716                 let mut def = Def::Err;
2717                 let ty = hir_ty_to_ty(cx.tcx, self);
2718                 if let ty::TyProjection(proj) = ty.sty {
2719                     def = Def::Trait(proj.trait_ref(cx.tcx).def_id);
2720                 }
2721                 let trait_path = hir::Path {
2722                     span: self.span,
2723                     def,
2724                     segments: vec![].into(),
2725                 };
2726                 Type::QPath {
2727                     name: segment.name.clean(cx),
2728                     self_type: box qself.clean(cx),
2729                     trait_: box resolve_type(cx, trait_path.clean(cx), self.id)
2730                 }
2731             }
2732             TyTraitObject(ref bounds, ref lifetime) => {
2733                 match bounds[0].clean(cx).trait_ {
2734                     ResolvedPath { path, typarams: None, did, is_generic } => {
2735                         let mut bounds: Vec<_> = bounds[1..].iter().map(|bound| {
2736                             TraitBound(bound.clean(cx), hir::TraitBoundModifier::None)
2737                         }).collect();
2738                         if !lifetime.is_elided() {
2739                             bounds.push(RegionBound(lifetime.clean(cx)));
2740                         }
2741                         ResolvedPath {
2742                             path,
2743                             typarams: Some(bounds),
2744                             did,
2745                             is_generic,
2746                         }
2747                     }
2748                     _ => Infer // shouldn't happen
2749                 }
2750             }
2751             TyBareFn(ref barefn) => BareFunction(box barefn.clean(cx)),
2752             TyImplTraitExistential(ref exist_ty, ref _lts) => ImplTrait(exist_ty.bounds.clean(cx)),
2753             TyInfer | TyErr => Infer,
2754             TyTypeof(..) => panic!("Unimplemented type {:?}", self.node),
2755         }
2756     }
2757 }
2758
2759 impl<'tcx> Clean<Type> for Ty<'tcx> {
2760     fn clean(&self, cx: &DocContext) -> Type {
2761         match self.sty {
2762             ty::TyNever => Never,
2763             ty::TyBool => Primitive(PrimitiveType::Bool),
2764             ty::TyChar => Primitive(PrimitiveType::Char),
2765             ty::TyInt(int_ty) => Primitive(int_ty.into()),
2766             ty::TyUint(uint_ty) => Primitive(uint_ty.into()),
2767             ty::TyFloat(float_ty) => Primitive(float_ty.into()),
2768             ty::TyStr => Primitive(PrimitiveType::Str),
2769             ty::TySlice(ty) => Slice(box ty.clean(cx)),
2770             ty::TyArray(ty, n) => {
2771                 let mut n = cx.tcx.lift(&n).unwrap();
2772                 if let ConstVal::Unevaluated(def_id, substs) = n.val {
2773                     let param_env = cx.tcx.param_env(def_id);
2774                     let cid = GlobalId {
2775                         instance: ty::Instance::new(def_id, substs),
2776                         promoted: None
2777                     };
2778                     if let Ok(new_n) = cx.tcx.const_eval(param_env.and(cid)) {
2779                         n = new_n;
2780                     }
2781                 };
2782                 let n = print_const(cx, n);
2783                 Array(box ty.clean(cx), n)
2784             }
2785             ty::TyRawPtr(mt) => RawPointer(mt.mutbl.clean(cx), box mt.ty.clean(cx)),
2786             ty::TyRef(r, ty, mutbl) => BorrowedRef {
2787                 lifetime: r.clean(cx),
2788                 mutability: mutbl.clean(cx),
2789                 type_: box ty.clean(cx),
2790             },
2791             ty::TyFnDef(..) |
2792             ty::TyFnPtr(_) => {
2793                 let ty = cx.tcx.lift(self).unwrap();
2794                 let sig = ty.fn_sig(cx.tcx);
2795                 BareFunction(box BareFunctionDecl {
2796                     unsafety: sig.unsafety(),
2797                     generic_params: Vec::new(),
2798                     decl: (cx.tcx.hir.local_def_id(ast::CRATE_NODE_ID), sig).clean(cx),
2799                     abi: sig.abi(),
2800                 })
2801             }
2802             ty::TyAdt(def, substs) => {
2803                 let did = def.did;
2804                 let kind = match def.adt_kind() {
2805                     AdtKind::Struct => TypeKind::Struct,
2806                     AdtKind::Union => TypeKind::Union,
2807                     AdtKind::Enum => TypeKind::Enum,
2808                 };
2809                 inline::record_extern_fqn(cx, did, kind);
2810                 let path = external_path(cx, &cx.tcx.item_name(did).as_str(),
2811                                          None, false, vec![], substs);
2812                 ResolvedPath {
2813                     path,
2814                     typarams: None,
2815                     did,
2816                     is_generic: false,
2817                 }
2818             }
2819             ty::TyForeign(did) => {
2820                 inline::record_extern_fqn(cx, did, TypeKind::Foreign);
2821                 let path = external_path(cx, &cx.tcx.item_name(did).as_str(),
2822                                          None, false, vec![], Substs::empty());
2823                 ResolvedPath {
2824                     path: path,
2825                     typarams: None,
2826                     did: did,
2827                     is_generic: false,
2828                 }
2829             }
2830             ty::TyDynamic(ref obj, ref reg) => {
2831                 if let Some(principal) = obj.principal() {
2832                     let did = principal.def_id();
2833                     inline::record_extern_fqn(cx, did, TypeKind::Trait);
2834
2835                     let mut typarams = vec![];
2836                     reg.clean(cx).map(|b| typarams.push(RegionBound(b)));
2837                     for did in obj.auto_traits() {
2838                         let empty = cx.tcx.intern_substs(&[]);
2839                         let path = external_path(cx, &cx.tcx.item_name(did).as_str(),
2840                             Some(did), false, vec![], empty);
2841                         inline::record_extern_fqn(cx, did, TypeKind::Trait);
2842                         let bound = TraitBound(PolyTrait {
2843                             trait_: ResolvedPath {
2844                                 path,
2845                                 typarams: None,
2846                                 did,
2847                                 is_generic: false,
2848                             },
2849                             generic_params: Vec::new(),
2850                         }, hir::TraitBoundModifier::None);
2851                         typarams.push(bound);
2852                     }
2853
2854                     let mut bindings = vec![];
2855                     for pb in obj.projection_bounds() {
2856                         bindings.push(TypeBinding {
2857                             name: cx.tcx.associated_item(pb.item_def_id()).name.clean(cx),
2858                             ty: pb.skip_binder().ty.clean(cx)
2859                         });
2860                     }
2861
2862                     let path = external_path(cx, &cx.tcx.item_name(did).as_str(), Some(did),
2863                         false, bindings, principal.skip_binder().substs);
2864                     ResolvedPath {
2865                         path,
2866                         typarams: Some(typarams),
2867                         did,
2868                         is_generic: false,
2869                     }
2870                 } else {
2871                     Never
2872                 }
2873             }
2874             ty::TyTuple(ref t) => Tuple(t.clean(cx)),
2875
2876             ty::TyProjection(ref data) => data.clean(cx),
2877
2878             ty::TyParam(ref p) => Generic(p.name.to_string()),
2879
2880             ty::TyAnon(def_id, substs) => {
2881                 // Grab the "TraitA + TraitB" from `impl TraitA + TraitB`,
2882                 // by looking up the projections associated with the def_id.
2883                 let predicates_of = cx.tcx.predicates_of(def_id);
2884                 let substs = cx.tcx.lift(&substs).unwrap();
2885                 let bounds = predicates_of.instantiate(cx.tcx, substs);
2886                 let mut regions = vec![];
2887                 let mut has_sized = false;
2888                 let mut bounds = bounds.predicates.iter().filter_map(|predicate| {
2889                     let trait_ref = if let Some(tr) = predicate.to_opt_poly_trait_ref() {
2890                         tr
2891                     } else if let ty::Predicate::TypeOutlives(pred) = *predicate {
2892                         // these should turn up at the end
2893                         pred.skip_binder().1.clean(cx).map(|r| regions.push(RegionBound(r)));
2894                         return None;
2895                     } else {
2896                         return None;
2897                     };
2898
2899                     if let Some(sized) = cx.tcx.lang_items().sized_trait() {
2900                         if trait_ref.def_id() == sized {
2901                             has_sized = true;
2902                             return None;
2903                         }
2904                     }
2905
2906
2907                     let bounds = bounds.predicates.iter().filter_map(|pred|
2908                         if let ty::Predicate::Projection(proj) = *pred {
2909                             let proj = proj.skip_binder();
2910                             if proj.projection_ty.trait_ref(cx.tcx) == *trait_ref.skip_binder() {
2911                                 Some(TypeBinding {
2912                                     name: cx.tcx.associated_item(proj.projection_ty.item_def_id)
2913                                                 .name.clean(cx),
2914                                     ty: proj.ty.clean(cx),
2915                                 })
2916                             } else {
2917                                 None
2918                             }
2919                         } else {
2920                             None
2921                         }
2922                     ).collect();
2923
2924                     Some((trait_ref.skip_binder(), bounds).clean(cx))
2925                 }).collect::<Vec<_>>();
2926                 bounds.extend(regions);
2927                 if !has_sized && !bounds.is_empty() {
2928                     bounds.insert(0, TyParamBound::maybe_sized(cx));
2929                 }
2930                 ImplTrait(bounds)
2931             }
2932
2933             ty::TyClosure(..) | ty::TyGenerator(..) => Tuple(vec![]), // FIXME(pcwalton)
2934
2935             ty::TyGeneratorWitness(..) => panic!("TyGeneratorWitness"),
2936             ty::TyInfer(..) => panic!("TyInfer"),
2937             ty::TyError => panic!("TyError"),
2938         }
2939     }
2940 }
2941
2942 impl Clean<Item> for hir::StructField {
2943     fn clean(&self, cx: &DocContext) -> Item {
2944         Item {
2945             name: Some(self.name).clean(cx),
2946             attrs: self.attrs.clean(cx),
2947             source: self.span.clean(cx),
2948             visibility: self.vis.clean(cx),
2949             stability: get_stability(cx, cx.tcx.hir.local_def_id(self.id)),
2950             deprecation: get_deprecation(cx, cx.tcx.hir.local_def_id(self.id)),
2951             def_id: cx.tcx.hir.local_def_id(self.id),
2952             inner: StructFieldItem(self.ty.clean(cx)),
2953         }
2954     }
2955 }
2956
2957 impl<'tcx> Clean<Item> for ty::FieldDef {
2958     fn clean(&self, cx: &DocContext) -> Item {
2959         Item {
2960             name: Some(self.name).clean(cx),
2961             attrs: cx.tcx.get_attrs(self.did).clean(cx),
2962             source: cx.tcx.def_span(self.did).clean(cx),
2963             visibility: self.vis.clean(cx),
2964             stability: get_stability(cx, self.did),
2965             deprecation: get_deprecation(cx, self.did),
2966             def_id: self.did,
2967             inner: StructFieldItem(cx.tcx.type_of(self.did).clean(cx)),
2968         }
2969     }
2970 }
2971
2972 #[derive(Clone, PartialEq, Eq, RustcDecodable, RustcEncodable, Debug)]
2973 pub enum Visibility {
2974     Public,
2975     Inherited,
2976 }
2977
2978 impl Clean<Option<Visibility>> for hir::Visibility {
2979     fn clean(&self, _: &DocContext) -> Option<Visibility> {
2980         Some(if *self == hir::Visibility::Public { Public } else { Inherited })
2981     }
2982 }
2983
2984 impl Clean<Option<Visibility>> for ty::Visibility {
2985     fn clean(&self, _: &DocContext) -> Option<Visibility> {
2986         Some(if *self == ty::Visibility::Public { Public } else { Inherited })
2987     }
2988 }
2989
2990 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
2991 pub struct Struct {
2992     pub struct_type: doctree::StructType,
2993     pub generics: Generics,
2994     pub fields: Vec<Item>,
2995     pub fields_stripped: bool,
2996 }
2997
2998 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
2999 pub struct Union {
3000     pub struct_type: doctree::StructType,
3001     pub generics: Generics,
3002     pub fields: Vec<Item>,
3003     pub fields_stripped: bool,
3004 }
3005
3006 impl Clean<Vec<Item>> for doctree::Struct {
3007     fn clean(&self, cx: &DocContext) -> Vec<Item> {
3008         let name = self.name.clean(cx);
3009         let mut ret = get_auto_traits_with_node_id(cx, self.id, name.clone());
3010
3011         ret.push(Item {
3012             name: Some(name),
3013             attrs: self.attrs.clean(cx),
3014             source: self.whence.clean(cx),
3015             def_id: cx.tcx.hir.local_def_id(self.id),
3016             visibility: self.vis.clean(cx),
3017             stability: self.stab.clean(cx),
3018             deprecation: self.depr.clean(cx),
3019             inner: StructItem(Struct {
3020                 struct_type: self.struct_type,
3021                 generics: self.generics.clean(cx),
3022                 fields: self.fields.clean(cx),
3023                 fields_stripped: false,
3024             }),
3025         });
3026
3027         ret
3028     }
3029 }
3030
3031 impl Clean<Vec<Item>> for doctree::Union {
3032     fn clean(&self, cx: &DocContext) -> Vec<Item> {
3033         let name = self.name.clean(cx);
3034         let mut ret = get_auto_traits_with_node_id(cx, self.id, name.clone());
3035
3036         ret.push(Item {
3037             name: Some(name),
3038             attrs: self.attrs.clean(cx),
3039             source: self.whence.clean(cx),
3040             def_id: cx.tcx.hir.local_def_id(self.id),
3041             visibility: self.vis.clean(cx),
3042             stability: self.stab.clean(cx),
3043             deprecation: self.depr.clean(cx),
3044             inner: UnionItem(Union {
3045                 struct_type: self.struct_type,
3046                 generics: self.generics.clean(cx),
3047                 fields: self.fields.clean(cx),
3048                 fields_stripped: false,
3049             }),
3050         });
3051
3052         ret
3053     }
3054 }
3055
3056 /// This is a more limited form of the standard Struct, different in that
3057 /// it lacks the things most items have (name, id, parameterization). Found
3058 /// only as a variant in an enum.
3059 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
3060 pub struct VariantStruct {
3061     pub struct_type: doctree::StructType,
3062     pub fields: Vec<Item>,
3063     pub fields_stripped: bool,
3064 }
3065
3066 impl Clean<VariantStruct> for ::rustc::hir::VariantData {
3067     fn clean(&self, cx: &DocContext) -> VariantStruct {
3068         VariantStruct {
3069             struct_type: doctree::struct_type_from_def(self),
3070             fields: self.fields().iter().map(|x| x.clean(cx)).collect(),
3071             fields_stripped: false,
3072         }
3073     }
3074 }
3075
3076 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
3077 pub struct Enum {
3078     pub variants: Vec<Item>,
3079     pub generics: Generics,
3080     pub variants_stripped: bool,
3081 }
3082
3083 impl Clean<Vec<Item>> for doctree::Enum {
3084     fn clean(&self, cx: &DocContext) -> Vec<Item> {
3085         let name = self.name.clean(cx);
3086         let mut ret = get_auto_traits_with_node_id(cx, self.id, name.clone());
3087
3088         ret.push(Item {
3089             name: Some(name),
3090             attrs: self.attrs.clean(cx),
3091             source: self.whence.clean(cx),
3092             def_id: cx.tcx.hir.local_def_id(self.id),
3093             visibility: self.vis.clean(cx),
3094             stability: self.stab.clean(cx),
3095             deprecation: self.depr.clean(cx),
3096             inner: EnumItem(Enum {
3097                 variants: self.variants.clean(cx),
3098                 generics: self.generics.clean(cx),
3099                 variants_stripped: false,
3100             }),
3101         });
3102
3103         ret
3104     }
3105 }
3106
3107 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
3108 pub struct Variant {
3109     pub kind: VariantKind,
3110 }
3111
3112 impl Clean<Item> for doctree::Variant {
3113     fn clean(&self, cx: &DocContext) -> Item {
3114         Item {
3115             name: Some(self.name.clean(cx)),
3116             attrs: self.attrs.clean(cx),
3117             source: self.whence.clean(cx),
3118             visibility: None,
3119             stability: self.stab.clean(cx),
3120             deprecation: self.depr.clean(cx),
3121             def_id: cx.tcx.hir.local_def_id(self.def.id()),
3122             inner: VariantItem(Variant {
3123                 kind: self.def.clean(cx),
3124             }),
3125         }
3126     }
3127 }
3128
3129 impl<'tcx> Clean<Item> for ty::VariantDef {
3130     fn clean(&self, cx: &DocContext) -> Item {
3131         let kind = match self.ctor_kind {
3132             CtorKind::Const => VariantKind::CLike,
3133             CtorKind::Fn => {
3134                 VariantKind::Tuple(
3135                     self.fields.iter().map(|f| cx.tcx.type_of(f.did).clean(cx)).collect()
3136                 )
3137             }
3138             CtorKind::Fictive => {
3139                 VariantKind::Struct(VariantStruct {
3140                     struct_type: doctree::Plain,
3141                     fields_stripped: false,
3142                     fields: self.fields.iter().map(|field| {
3143                         Item {
3144                             source: cx.tcx.def_span(field.did).clean(cx),
3145                             name: Some(field.name.clean(cx)),
3146                             attrs: cx.tcx.get_attrs(field.did).clean(cx),
3147                             visibility: field.vis.clean(cx),
3148                             def_id: field.did,
3149                             stability: get_stability(cx, field.did),
3150                             deprecation: get_deprecation(cx, field.did),
3151                             inner: StructFieldItem(cx.tcx.type_of(field.did).clean(cx))
3152                         }
3153                     }).collect()
3154                 })
3155             }
3156         };
3157         Item {
3158             name: Some(self.name.clean(cx)),
3159             attrs: inline::load_attrs(cx, self.did),
3160             source: cx.tcx.def_span(self.did).clean(cx),
3161             visibility: Some(Inherited),
3162             def_id: self.did,
3163             inner: VariantItem(Variant { kind: kind }),
3164             stability: get_stability(cx, self.did),
3165             deprecation: get_deprecation(cx, self.did),
3166         }
3167     }
3168 }
3169
3170 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
3171 pub enum VariantKind {
3172     CLike,
3173     Tuple(Vec<Type>),
3174     Struct(VariantStruct),
3175 }
3176
3177 impl Clean<VariantKind> for hir::VariantData {
3178     fn clean(&self, cx: &DocContext) -> VariantKind {
3179         if self.is_struct() {
3180             VariantKind::Struct(self.clean(cx))
3181         } else if self.is_unit() {
3182             VariantKind::CLike
3183         } else {
3184             VariantKind::Tuple(self.fields().iter().map(|x| x.ty.clean(cx)).collect())
3185         }
3186     }
3187 }
3188
3189 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
3190 pub struct Span {
3191     pub filename: FileName,
3192     pub loline: usize,
3193     pub locol: usize,
3194     pub hiline: usize,
3195     pub hicol: usize,
3196 }
3197
3198 impl Span {
3199     pub fn empty() -> Span {
3200         Span {
3201             filename: FileName::Anon,
3202             loline: 0, locol: 0,
3203             hiline: 0, hicol: 0,
3204         }
3205     }
3206 }
3207
3208 impl Clean<Span> for syntax_pos::Span {
3209     fn clean(&self, cx: &DocContext) -> Span {
3210         if *self == DUMMY_SP {
3211             return Span::empty();
3212         }
3213
3214         let cm = cx.sess().codemap();
3215         let filename = cm.span_to_filename(*self);
3216         let lo = cm.lookup_char_pos(self.lo());
3217         let hi = cm.lookup_char_pos(self.hi());
3218         Span {
3219             filename,
3220             loline: lo.line,
3221             locol: lo.col.to_usize(),
3222             hiline: hi.line,
3223             hicol: hi.col.to_usize(),
3224         }
3225     }
3226 }
3227
3228 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Debug, Hash)]
3229 pub struct Path {
3230     pub global: bool,
3231     pub def: Def,
3232     pub segments: Vec<PathSegment>,
3233 }
3234
3235 impl Path {
3236     pub fn singleton(name: String) -> Path {
3237         Path {
3238             global: false,
3239             def: Def::Err,
3240             segments: vec![PathSegment {
3241                 name,
3242                 params: PathParameters::AngleBracketed {
3243                     lifetimes: Vec::new(),
3244                     types: Vec::new(),
3245                     bindings: Vec::new(),
3246                 }
3247             }]
3248         }
3249     }
3250
3251     pub fn last_name(&self) -> &str {
3252         self.segments.last().unwrap().name.as_str()
3253     }
3254 }
3255
3256 impl Clean<Path> for hir::Path {
3257     fn clean(&self, cx: &DocContext) -> Path {
3258         Path {
3259             global: self.is_global(),
3260             def: self.def,
3261             segments: if self.is_global() { &self.segments[1..] } else { &self.segments }.clean(cx),
3262         }
3263     }
3264 }
3265
3266 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Debug, Hash)]
3267 pub enum PathParameters {
3268     AngleBracketed {
3269         lifetimes: Vec<Lifetime>,
3270         types: Vec<Type>,
3271         bindings: Vec<TypeBinding>,
3272     },
3273     Parenthesized {
3274         inputs: Vec<Type>,
3275         output: Option<Type>,
3276     }
3277 }
3278
3279 impl Clean<PathParameters> for hir::PathParameters {
3280     fn clean(&self, cx: &DocContext) -> PathParameters {
3281         if self.parenthesized {
3282             let output = self.bindings[0].ty.clean(cx);
3283             PathParameters::Parenthesized {
3284                 inputs: self.inputs().clean(cx),
3285                 output: if output != Type::Tuple(Vec::new()) { Some(output) } else { None }
3286             }
3287         } else {
3288             PathParameters::AngleBracketed {
3289                 lifetimes: if self.lifetimes.iter().all(|lt| lt.is_elided()) {
3290                     vec![]
3291                 } else {
3292                     self.lifetimes.clean(cx)
3293                 },
3294                 types: self.types.clean(cx),
3295                 bindings: self.bindings.clean(cx),
3296             }
3297         }
3298     }
3299 }
3300
3301 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Debug, Hash)]
3302 pub struct PathSegment {
3303     pub name: String,
3304     pub params: PathParameters,
3305 }
3306
3307 impl Clean<PathSegment> for hir::PathSegment {
3308     fn clean(&self, cx: &DocContext) -> PathSegment {
3309         PathSegment {
3310             name: self.name.clean(cx),
3311             params: self.with_parameters(|parameters| parameters.clean(cx))
3312         }
3313     }
3314 }
3315
3316 fn strip_type(ty: Type) -> Type {
3317     match ty {
3318         Type::ResolvedPath { path, typarams, did, is_generic } => {
3319             Type::ResolvedPath { path: strip_path(&path), typarams, did, is_generic }
3320         }
3321         Type::Tuple(inner_tys) => {
3322             Type::Tuple(inner_tys.iter().map(|t| strip_type(t.clone())).collect())
3323         }
3324         Type::Slice(inner_ty) => Type::Slice(Box::new(strip_type(*inner_ty))),
3325         Type::Array(inner_ty, s) => Type::Array(Box::new(strip_type(*inner_ty)), s),
3326         Type::Unique(inner_ty) => Type::Unique(Box::new(strip_type(*inner_ty))),
3327         Type::RawPointer(m, inner_ty) => Type::RawPointer(m, Box::new(strip_type(*inner_ty))),
3328         Type::BorrowedRef { lifetime, mutability, type_ } => {
3329             Type::BorrowedRef { lifetime, mutability, type_: Box::new(strip_type(*type_)) }
3330         }
3331         Type::QPath { name, self_type, trait_ } => {
3332             Type::QPath {
3333                 name,
3334                 self_type: Box::new(strip_type(*self_type)), trait_: Box::new(strip_type(*trait_))
3335             }
3336         }
3337         _ => ty
3338     }
3339 }
3340
3341 fn strip_path(path: &Path) -> Path {
3342     let segments = path.segments.iter().map(|s| {
3343         PathSegment {
3344             name: s.name.clone(),
3345             params: PathParameters::AngleBracketed {
3346                 lifetimes: Vec::new(),
3347                 types: Vec::new(),
3348                 bindings: Vec::new(),
3349             }
3350         }
3351     }).collect();
3352
3353     Path {
3354         global: path.global,
3355         def: path.def.clone(),
3356         segments,
3357     }
3358 }
3359
3360 fn qpath_to_string(p: &hir::QPath) -> String {
3361     let segments = match *p {
3362         hir::QPath::Resolved(_, ref path) => &path.segments,
3363         hir::QPath::TypeRelative(_, ref segment) => return segment.name.to_string(),
3364     };
3365
3366     let mut s = String::new();
3367     for (i, seg) in segments.iter().enumerate() {
3368         if i > 0 {
3369             s.push_str("::");
3370         }
3371         if seg.name != keywords::CrateRoot.name() {
3372             s.push_str(&*seg.name.as_str());
3373         }
3374     }
3375     s
3376 }
3377
3378 impl Clean<String> for ast::Name {
3379     fn clean(&self, _: &DocContext) -> String {
3380         self.to_string()
3381     }
3382 }
3383
3384 impl Clean<String> for InternedString {
3385     fn clean(&self, _: &DocContext) -> String {
3386         self.to_string()
3387     }
3388 }
3389
3390 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
3391 pub struct Typedef {
3392     pub type_: Type,
3393     pub generics: Generics,
3394 }
3395
3396 impl Clean<Item> for doctree::Typedef {
3397     fn clean(&self, cx: &DocContext) -> Item {
3398         Item {
3399             name: Some(self.name.clean(cx)),
3400             attrs: self.attrs.clean(cx),
3401             source: self.whence.clean(cx),
3402             def_id: cx.tcx.hir.local_def_id(self.id.clone()),
3403             visibility: self.vis.clean(cx),
3404             stability: self.stab.clean(cx),
3405             deprecation: self.depr.clean(cx),
3406             inner: TypedefItem(Typedef {
3407                 type_: self.ty.clean(cx),
3408                 generics: self.gen.clean(cx),
3409             }, false),
3410         }
3411     }
3412 }
3413
3414 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Debug, Hash)]
3415 pub struct BareFunctionDecl {
3416     pub unsafety: hir::Unsafety,
3417     pub generic_params: Vec<GenericParam>,
3418     pub decl: FnDecl,
3419     pub abi: Abi,
3420 }
3421
3422 impl Clean<BareFunctionDecl> for hir::BareFnTy {
3423     fn clean(&self, cx: &DocContext) -> BareFunctionDecl {
3424         let (generic_params, decl) = enter_impl_trait(cx, || {
3425             (self.generic_params.clean(cx), (&*self.decl, &self.arg_names[..]).clean(cx))
3426         });
3427         BareFunctionDecl {
3428             unsafety: self.unsafety,
3429             decl,
3430             generic_params,
3431             abi: self.abi,
3432         }
3433     }
3434 }
3435
3436 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
3437 pub struct Static {
3438     pub type_: Type,
3439     pub mutability: Mutability,
3440     /// It's useful to have the value of a static documented, but I have no
3441     /// desire to represent expressions (that'd basically be all of the AST,
3442     /// which is huge!). So, have a string.
3443     pub expr: String,
3444 }
3445
3446 impl Clean<Item> for doctree::Static {
3447     fn clean(&self, cx: &DocContext) -> Item {
3448         debug!("cleaning static {}: {:?}", self.name.clean(cx), self);
3449         Item {
3450             name: Some(self.name.clean(cx)),
3451             attrs: self.attrs.clean(cx),
3452             source: self.whence.clean(cx),
3453             def_id: cx.tcx.hir.local_def_id(self.id),
3454             visibility: self.vis.clean(cx),
3455             stability: self.stab.clean(cx),
3456             deprecation: self.depr.clean(cx),
3457             inner: StaticItem(Static {
3458                 type_: self.type_.clean(cx),
3459                 mutability: self.mutability.clean(cx),
3460                 expr: print_const_expr(cx, self.expr),
3461             }),
3462         }
3463     }
3464 }
3465
3466 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
3467 pub struct Constant {
3468     pub type_: Type,
3469     pub expr: String,
3470 }
3471
3472 impl Clean<Item> for doctree::Constant {
3473     fn clean(&self, cx: &DocContext) -> Item {
3474         Item {
3475             name: Some(self.name.clean(cx)),
3476             attrs: self.attrs.clean(cx),
3477             source: self.whence.clean(cx),
3478             def_id: cx.tcx.hir.local_def_id(self.id),
3479             visibility: self.vis.clean(cx),
3480             stability: self.stab.clean(cx),
3481             deprecation: self.depr.clean(cx),
3482             inner: ConstantItem(Constant {
3483                 type_: self.type_.clean(cx),
3484                 expr: print_const_expr(cx, self.expr),
3485             }),
3486         }
3487     }
3488 }
3489
3490 #[derive(Debug, Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Copy, Hash)]
3491 pub enum Mutability {
3492     Mutable,
3493     Immutable,
3494 }
3495
3496 impl Clean<Mutability> for hir::Mutability {
3497     fn clean(&self, _: &DocContext) -> Mutability {
3498         match self {
3499             &hir::MutMutable => Mutable,
3500             &hir::MutImmutable => Immutable,
3501         }
3502     }
3503 }
3504
3505 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Copy, Debug, Hash)]
3506 pub enum ImplPolarity {
3507     Positive,
3508     Negative,
3509 }
3510
3511 impl Clean<ImplPolarity> for hir::ImplPolarity {
3512     fn clean(&self, _: &DocContext) -> ImplPolarity {
3513         match self {
3514             &hir::ImplPolarity::Positive => ImplPolarity::Positive,
3515             &hir::ImplPolarity::Negative => ImplPolarity::Negative,
3516         }
3517     }
3518 }
3519
3520 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
3521 pub struct Impl {
3522     pub unsafety: hir::Unsafety,
3523     pub generics: Generics,
3524     pub provided_trait_methods: FxHashSet<String>,
3525     pub trait_: Option<Type>,
3526     pub for_: Type,
3527     pub items: Vec<Item>,
3528     pub polarity: Option<ImplPolarity>,
3529     pub synthetic: bool,
3530 }
3531
3532 pub fn get_auto_traits_with_node_id(cx: &DocContext, id: ast::NodeId, name: String) -> Vec<Item> {
3533     let finder = AutoTraitFinder::new(cx);
3534     finder.get_with_node_id(id, name)
3535 }
3536
3537 pub fn get_auto_traits_with_def_id(cx: &DocContext, id: DefId) -> Vec<Item> {
3538     let finder = AutoTraitFinder::new(cx);
3539
3540     finder.get_with_def_id(id)
3541 }
3542
3543 impl Clean<Vec<Item>> for doctree::Impl {
3544     fn clean(&self, cx: &DocContext) -> Vec<Item> {
3545         let mut ret = Vec::new();
3546         let trait_ = self.trait_.clean(cx);
3547         let items = self.items.clean(cx);
3548
3549         // If this impl block is an implementation of the Deref trait, then we
3550         // need to try inlining the target's inherent impl blocks as well.
3551         if trait_.def_id() == cx.tcx.lang_items().deref_trait() {
3552             build_deref_target_impls(cx, &items, &mut ret);
3553         }
3554
3555         let provided = trait_.def_id().map(|did| {
3556             cx.tcx.provided_trait_methods(did)
3557                   .into_iter()
3558                   .map(|meth| meth.name.to_string())
3559                   .collect()
3560         }).unwrap_or(FxHashSet());
3561
3562         ret.push(Item {
3563             name: None,
3564             attrs: self.attrs.clean(cx),
3565             source: self.whence.clean(cx),
3566             def_id: cx.tcx.hir.local_def_id(self.id),
3567             visibility: self.vis.clean(cx),
3568             stability: self.stab.clean(cx),
3569             deprecation: self.depr.clean(cx),
3570             inner: ImplItem(Impl {
3571                 unsafety: self.unsafety,
3572                 generics: self.generics.clean(cx),
3573                 provided_trait_methods: provided,
3574                 trait_,
3575                 for_: self.for_.clean(cx),
3576                 items,
3577                 polarity: Some(self.polarity.clean(cx)),
3578                 synthetic: false,
3579             })
3580         });
3581         ret
3582     }
3583 }
3584
3585 fn build_deref_target_impls(cx: &DocContext,
3586                             items: &[Item],
3587                             ret: &mut Vec<Item>) {
3588     use self::PrimitiveType::*;
3589     let tcx = cx.tcx;
3590
3591     for item in items {
3592         let target = match item.inner {
3593             TypedefItem(ref t, true) => &t.type_,
3594             _ => continue,
3595         };
3596         let primitive = match *target {
3597             ResolvedPath { did, .. } if did.is_local() => continue,
3598             ResolvedPath { did, .. } => {
3599                 // We set the last parameter to false to avoid looking for auto-impls for traits
3600                 // and therefore avoid an ICE.
3601                 // The reason behind this is that auto-traits don't propagate through Deref so
3602                 // we're not supposed to synthesise impls for them.
3603                 ret.extend(inline::build_impls(cx, did, false));
3604                 continue
3605             }
3606             _ => match target.primitive_type() {
3607                 Some(prim) => prim,
3608                 None => continue,
3609             }
3610         };
3611         let did = match primitive {
3612             Isize => tcx.lang_items().isize_impl(),
3613             I8 => tcx.lang_items().i8_impl(),
3614             I16 => tcx.lang_items().i16_impl(),
3615             I32 => tcx.lang_items().i32_impl(),
3616             I64 => tcx.lang_items().i64_impl(),
3617             I128 => tcx.lang_items().i128_impl(),
3618             Usize => tcx.lang_items().usize_impl(),
3619             U8 => tcx.lang_items().u8_impl(),
3620             U16 => tcx.lang_items().u16_impl(),
3621             U32 => tcx.lang_items().u32_impl(),
3622             U64 => tcx.lang_items().u64_impl(),
3623             U128 => tcx.lang_items().u128_impl(),
3624             F32 => tcx.lang_items().f32_impl(),
3625             F64 => tcx.lang_items().f64_impl(),
3626             Char => tcx.lang_items().char_impl(),
3627             Bool => None,
3628             Str => tcx.lang_items().str_impl(),
3629             Slice => tcx.lang_items().slice_impl(),
3630             Array => tcx.lang_items().slice_impl(),
3631             Tuple => None,
3632             Unit => None,
3633             RawPointer => tcx.lang_items().const_ptr_impl(),
3634             Reference => None,
3635             Fn => None,
3636             Never => None,
3637         };
3638         if let Some(did) = did {
3639             if !did.is_local() {
3640                 inline::build_impl(cx, did, ret);
3641             }
3642         }
3643     }
3644 }
3645
3646 impl Clean<Item> for doctree::ExternCrate {
3647     fn clean(&self, cx: &DocContext) -> Item {
3648         Item {
3649             name: None,
3650             attrs: self.attrs.clean(cx),
3651             source: self.whence.clean(cx),
3652             def_id: DefId { krate: self.cnum, index: CRATE_DEF_INDEX },
3653             visibility: self.vis.clean(cx),
3654             stability: None,
3655             deprecation: None,
3656             inner: ExternCrateItem(self.name.clean(cx), self.path.clone())
3657         }
3658     }
3659 }
3660
3661 impl Clean<Vec<Item>> for doctree::Import {
3662     fn clean(&self, cx: &DocContext) -> Vec<Item> {
3663         // We consider inlining the documentation of `pub use` statements, but we
3664         // forcefully don't inline if this is not public or if the
3665         // #[doc(no_inline)] attribute is present.
3666         // Don't inline doc(hidden) imports so they can be stripped at a later stage.
3667         let denied = self.vis != hir::Public || self.attrs.iter().any(|a| {
3668             a.name() == "doc" && match a.meta_item_list() {
3669                 Some(l) => attr::list_contains_name(&l, "no_inline") ||
3670                            attr::list_contains_name(&l, "hidden"),
3671                 None => false,
3672             }
3673         });
3674         let path = self.path.clean(cx);
3675         let inner = if self.glob {
3676             Import::Glob(resolve_use_source(cx, path))
3677         } else {
3678             let name = self.name;
3679             if !denied {
3680                 let mut visited = FxHashSet();
3681                 if let Some(items) = inline::try_inline(cx, path.def, name, &mut visited) {
3682                     return items;
3683                 }
3684             }
3685             Import::Simple(name.clean(cx), resolve_use_source(cx, path))
3686         };
3687         vec![Item {
3688             name: None,
3689             attrs: self.attrs.clean(cx),
3690             source: self.whence.clean(cx),
3691             def_id: cx.tcx.hir.local_def_id(ast::CRATE_NODE_ID),
3692             visibility: self.vis.clean(cx),
3693             stability: None,
3694             deprecation: None,
3695             inner: ImportItem(inner)
3696         }]
3697     }
3698 }
3699
3700 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
3701 pub enum Import {
3702     // use source as str;
3703     Simple(String, ImportSource),
3704     // use source::*;
3705     Glob(ImportSource)
3706 }
3707
3708 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
3709 pub struct ImportSource {
3710     pub path: Path,
3711     pub did: Option<DefId>,
3712 }
3713
3714 impl Clean<Vec<Item>> for hir::ForeignMod {
3715     fn clean(&self, cx: &DocContext) -> Vec<Item> {
3716         let mut items = self.items.clean(cx);
3717         for item in &mut items {
3718             if let ForeignFunctionItem(ref mut f) = item.inner {
3719                 f.abi = self.abi;
3720             }
3721         }
3722         items
3723     }
3724 }
3725
3726 impl Clean<Item> for hir::ForeignItem {
3727     fn clean(&self, cx: &DocContext) -> Item {
3728         let inner = match self.node {
3729             hir::ForeignItemFn(ref decl, ref names, ref generics) => {
3730                 let (generics, decl) = enter_impl_trait(cx, || {
3731                     (generics.clean(cx), (&**decl, &names[..]).clean(cx))
3732                 });
3733                 ForeignFunctionItem(Function {
3734                     decl,
3735                     generics,
3736                     unsafety: hir::Unsafety::Unsafe,
3737                     abi: Abi::Rust,
3738                     constness: hir::Constness::NotConst,
3739                 })
3740             }
3741             hir::ForeignItemStatic(ref ty, mutbl) => {
3742                 ForeignStaticItem(Static {
3743                     type_: ty.clean(cx),
3744                     mutability: if mutbl {Mutable} else {Immutable},
3745                     expr: "".to_string(),
3746                 })
3747             }
3748             hir::ForeignItemType => {
3749                 ForeignTypeItem
3750             }
3751         };
3752         Item {
3753             name: Some(self.name.clean(cx)),
3754             attrs: self.attrs.clean(cx),
3755             source: self.span.clean(cx),
3756             def_id: cx.tcx.hir.local_def_id(self.id),
3757             visibility: self.vis.clean(cx),
3758             stability: get_stability(cx, cx.tcx.hir.local_def_id(self.id)),
3759             deprecation: get_deprecation(cx, cx.tcx.hir.local_def_id(self.id)),
3760             inner,
3761         }
3762     }
3763 }
3764
3765 // Utilities
3766
3767 trait ToSource {
3768     fn to_src(&self, cx: &DocContext) -> String;
3769 }
3770
3771 impl ToSource for syntax_pos::Span {
3772     fn to_src(&self, cx: &DocContext) -> String {
3773         debug!("converting span {:?} to snippet", self.clean(cx));
3774         let sn = match cx.sess().codemap().span_to_snippet(*self) {
3775             Ok(x) => x.to_string(),
3776             Err(_) => "".to_string()
3777         };
3778         debug!("got snippet {}", sn);
3779         sn
3780     }
3781 }
3782
3783 fn name_from_pat(p: &hir::Pat) -> String {
3784     use rustc::hir::*;
3785     debug!("Trying to get a name from pattern: {:?}", p);
3786
3787     match p.node {
3788         PatKind::Wild => "_".to_string(),
3789         PatKind::Binding(_, _, ref p, _) => p.node.to_string(),
3790         PatKind::TupleStruct(ref p, ..) | PatKind::Path(ref p) => qpath_to_string(p),
3791         PatKind::Struct(ref name, ref fields, etc) => {
3792             format!("{} {{ {}{} }}", qpath_to_string(name),
3793                 fields.iter().map(|&Spanned { node: ref fp, .. }|
3794                                   format!("{}: {}", fp.name, name_from_pat(&*fp.pat)))
3795                              .collect::<Vec<String>>().join(", "),
3796                 if etc { ", ..." } else { "" }
3797             )
3798         }
3799         PatKind::Tuple(ref elts, _) => format!("({})", elts.iter().map(|p| name_from_pat(&**p))
3800                                             .collect::<Vec<String>>().join(", ")),
3801         PatKind::Box(ref p) => name_from_pat(&**p),
3802         PatKind::Ref(ref p, _) => name_from_pat(&**p),
3803         PatKind::Lit(..) => {
3804             warn!("tried to get argument name from PatKind::Lit, \
3805                   which is silly in function arguments");
3806             "()".to_string()
3807         },
3808         PatKind::Range(..) => panic!("tried to get argument name from PatKind::Range, \
3809                               which is not allowed in function arguments"),
3810         PatKind::Slice(ref begin, ref mid, ref end) => {
3811             let begin = begin.iter().map(|p| name_from_pat(&**p));
3812             let mid = mid.as_ref().map(|p| format!("..{}", name_from_pat(&**p))).into_iter();
3813             let end = end.iter().map(|p| name_from_pat(&**p));
3814             format!("[{}]", begin.chain(mid).chain(end).collect::<Vec<_>>().join(", "))
3815         },
3816     }
3817 }
3818
3819 fn print_const(cx: &DocContext, n: &ty::Const) -> String {
3820     match n.val {
3821         ConstVal::Unevaluated(def_id, _) => {
3822             if let Some(node_id) = cx.tcx.hir.as_local_node_id(def_id) {
3823                 print_const_expr(cx, cx.tcx.hir.body_owned_by(node_id))
3824             } else {
3825                 inline::print_inlined_const(cx, def_id)
3826             }
3827         },
3828         ConstVal::Value(..) => {
3829             let mut s = String::new();
3830             ::rustc::mir::fmt_const_val(&mut s, n).unwrap();
3831             // array lengths are obviously usize
3832             if s.ends_with("usize") {
3833                 let n = s.len() - "usize".len();
3834                 s.truncate(n);
3835             }
3836             s
3837         },
3838     }
3839 }
3840
3841 fn print_const_expr(cx: &DocContext, body: hir::BodyId) -> String {
3842     cx.tcx.hir.node_to_pretty_string(body.node_id)
3843 }
3844
3845 /// Given a type Path, resolve it to a Type using the TyCtxt
3846 fn resolve_type(cx: &DocContext,
3847                 path: Path,
3848                 id: ast::NodeId) -> Type {
3849     if id == ast::DUMMY_NODE_ID {
3850         debug!("resolve_type({:?})", path);
3851     } else {
3852         debug!("resolve_type({:?},{:?})", path, id);
3853     }
3854
3855     let is_generic = match path.def {
3856         Def::PrimTy(p) => match p {
3857             hir::TyStr => return Primitive(PrimitiveType::Str),
3858             hir::TyBool => return Primitive(PrimitiveType::Bool),
3859             hir::TyChar => return Primitive(PrimitiveType::Char),
3860             hir::TyInt(int_ty) => return Primitive(int_ty.into()),
3861             hir::TyUint(uint_ty) => return Primitive(uint_ty.into()),
3862             hir::TyFloat(float_ty) => return Primitive(float_ty.into()),
3863         },
3864         Def::SelfTy(..) if path.segments.len() == 1 => {
3865             return Generic(keywords::SelfType.name().to_string());
3866         }
3867         Def::TyParam(..) if path.segments.len() == 1 => {
3868             return Generic(format!("{:#}", path));
3869         }
3870         Def::SelfTy(..) | Def::TyParam(..) | Def::AssociatedTy(..) => true,
3871         _ => false,
3872     };
3873     let did = register_def(&*cx, path.def);
3874     ResolvedPath { path: path, typarams: None, did: did, is_generic: is_generic }
3875 }
3876
3877 fn register_def(cx: &DocContext, def: Def) -> DefId {
3878     debug!("register_def({:?})", def);
3879
3880     let (did, kind) = match def {
3881         Def::Fn(i) => (i, TypeKind::Function),
3882         Def::TyAlias(i) => (i, TypeKind::Typedef),
3883         Def::Enum(i) => (i, TypeKind::Enum),
3884         Def::Trait(i) => (i, TypeKind::Trait),
3885         Def::Struct(i) => (i, TypeKind::Struct),
3886         Def::Union(i) => (i, TypeKind::Union),
3887         Def::Mod(i) => (i, TypeKind::Module),
3888         Def::TyForeign(i) => (i, TypeKind::Foreign),
3889         Def::Const(i) => (i, TypeKind::Const),
3890         Def::Static(i, _) => (i, TypeKind::Static),
3891         Def::Variant(i) => (cx.tcx.parent_def_id(i).unwrap(), TypeKind::Enum),
3892         Def::Macro(i, _) => (i, TypeKind::Macro),
3893         Def::SelfTy(Some(def_id), _) => (def_id, TypeKind::Trait),
3894         Def::SelfTy(_, Some(impl_def_id)) => {
3895             return impl_def_id
3896         }
3897         _ => return def.def_id()
3898     };
3899     if did.is_local() { return did }
3900     inline::record_extern_fqn(cx, did, kind);
3901     if let TypeKind::Trait = kind {
3902         inline::record_extern_trait(cx, did);
3903     }
3904     did
3905 }
3906
3907 fn resolve_use_source(cx: &DocContext, path: Path) -> ImportSource {
3908     ImportSource {
3909         did: if path.def == Def::Err {
3910             None
3911         } else {
3912             Some(register_def(cx, path.def))
3913         },
3914         path,
3915     }
3916 }
3917
3918 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
3919 pub struct Macro {
3920     pub source: String,
3921     pub imported_from: Option<String>,
3922 }
3923
3924 impl Clean<Item> for doctree::Macro {
3925     fn clean(&self, cx: &DocContext) -> Item {
3926         let name = self.name.clean(cx);
3927         Item {
3928             name: Some(name.clone()),
3929             attrs: self.attrs.clean(cx),
3930             source: self.whence.clean(cx),
3931             visibility: Some(Public),
3932             stability: self.stab.clean(cx),
3933             deprecation: self.depr.clean(cx),
3934             def_id: self.def_id,
3935             inner: MacroItem(Macro {
3936                 source: format!("macro_rules! {} {{\n{}}}",
3937                                 name,
3938                                 self.matchers.iter().map(|span| {
3939                                     format!("    {} => {{ ... }};\n", span.to_src(cx))
3940                                 }).collect::<String>()),
3941                 imported_from: self.imported_from.clean(cx),
3942             }),
3943         }
3944     }
3945 }
3946
3947 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
3948 pub struct Stability {
3949     pub level: stability::StabilityLevel,
3950     pub feature: String,
3951     pub since: String,
3952     pub deprecated_since: String,
3953     pub deprecated_reason: String,
3954     pub unstable_reason: String,
3955     pub issue: Option<u32>
3956 }
3957
3958 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
3959 pub struct Deprecation {
3960     pub since: String,
3961     pub note: String,
3962 }
3963
3964 impl Clean<Stability> for attr::Stability {
3965     fn clean(&self, _: &DocContext) -> Stability {
3966         Stability {
3967             level: stability::StabilityLevel::from_attr_level(&self.level),
3968             feature: self.feature.to_string(),
3969             since: match self.level {
3970                 attr::Stable {ref since} => since.to_string(),
3971                 _ => "".to_string(),
3972             },
3973             deprecated_since: match self.rustc_depr {
3974                 Some(attr::RustcDeprecation {ref since, ..}) => since.to_string(),
3975                 _=> "".to_string(),
3976             },
3977             deprecated_reason: match self.rustc_depr {
3978                 Some(ref depr) => depr.reason.to_string(),
3979                 _ => "".to_string(),
3980             },
3981             unstable_reason: match self.level {
3982                 attr::Unstable { reason: Some(ref reason), .. } => reason.to_string(),
3983                 _ => "".to_string(),
3984             },
3985             issue: match self.level {
3986                 attr::Unstable {issue, ..} => Some(issue),
3987                 _ => None,
3988             }
3989         }
3990     }
3991 }
3992
3993 impl<'a> Clean<Stability> for &'a attr::Stability {
3994     fn clean(&self, dc: &DocContext) -> Stability {
3995         (**self).clean(dc)
3996     }
3997 }
3998
3999 impl Clean<Deprecation> for attr::Deprecation {
4000     fn clean(&self, _: &DocContext) -> Deprecation {
4001         Deprecation {
4002             since: self.since.as_ref().map_or("".to_string(), |s| s.to_string()),
4003             note: self.note.as_ref().map_or("".to_string(), |s| s.to_string()),
4004         }
4005     }
4006 }
4007
4008 /// An equality constraint on an associated type, e.g. `A=Bar` in `Foo<A=Bar>`
4009 #[derive(Clone, PartialEq, Eq, RustcDecodable, RustcEncodable, Debug, Hash)]
4010 pub struct TypeBinding {
4011     pub name: String,
4012     pub ty: Type
4013 }
4014
4015 impl Clean<TypeBinding> for hir::TypeBinding {
4016     fn clean(&self, cx: &DocContext) -> TypeBinding {
4017         TypeBinding {
4018             name: self.name.clean(cx),
4019             ty: self.ty.clean(cx)
4020         }
4021     }
4022 }
4023
4024 pub fn def_id_to_path(cx: &DocContext, did: DefId, name: Option<String>) -> Vec<String> {
4025     let crate_name = name.unwrap_or_else(|| cx.tcx.crate_name(did.krate).to_string());
4026     let relative = cx.tcx.def_path(did).data.into_iter().filter_map(|elem| {
4027         // extern blocks have an empty name
4028         let s = elem.data.to_string();
4029         if !s.is_empty() {
4030             Some(s)
4031         } else {
4032             None
4033         }
4034     });
4035     once(crate_name).chain(relative).collect()
4036 }
4037
4038 pub fn enter_impl_trait<F, R>(cx: &DocContext, f: F) -> R
4039 where
4040     F: FnOnce() -> R,
4041 {
4042     let old_bounds = mem::replace(&mut *cx.impl_trait_bounds.borrow_mut(), Default::default());
4043     let r = f();
4044     assert!(cx.impl_trait_bounds.borrow().is_empty());
4045     *cx.impl_trait_bounds.borrow_mut() = old_bounds;
4046     r
4047 }
4048
4049 // Start of code copied from rust-clippy
4050
4051 pub fn get_trait_def_id(tcx: &TyCtxt, path: &[&str], use_local: bool) -> Option<DefId> {
4052     if use_local {
4053         path_to_def_local(tcx, path)
4054     } else {
4055         path_to_def(tcx, path)
4056     }
4057 }
4058
4059 pub fn path_to_def_local(tcx: &TyCtxt, path: &[&str]) -> Option<DefId> {
4060     let krate = tcx.hir.krate();
4061     let mut items = krate.module.item_ids.clone();
4062     let mut path_it = path.iter().peekable();
4063
4064     loop {
4065         let segment = match path_it.next() {
4066             Some(segment) => segment,
4067             None => return None,
4068         };
4069
4070         for item_id in mem::replace(&mut items, HirVec::new()).iter() {
4071             let item = tcx.hir.expect_item(item_id.id);
4072             if item.name == *segment {
4073                 if path_it.peek().is_none() {
4074                     return Some(tcx.hir.local_def_id(item_id.id))
4075                 }
4076
4077                 items = match &item.node {
4078                     &hir::ItemMod(ref m) => m.item_ids.clone(),
4079                     _ => panic!("Unexpected item {:?} in path {:?} path")
4080                 };
4081                 break;
4082             }
4083         }
4084     }
4085 }
4086
4087 pub fn path_to_def(tcx: &TyCtxt, path: &[&str]) -> Option<DefId> {
4088     let crates = tcx.crates();
4089
4090     let krate = crates
4091         .iter()
4092         .find(|&&krate| tcx.crate_name(krate) == path[0]);
4093
4094     if let Some(krate) = krate {
4095         let krate = DefId {
4096             krate: *krate,
4097             index: CRATE_DEF_INDEX,
4098         };
4099         let mut items = tcx.item_children(krate);
4100         let mut path_it = path.iter().skip(1).peekable();
4101
4102         loop {
4103             let segment = match path_it.next() {
4104                 Some(segment) => segment,
4105                 None => return None,
4106             };
4107
4108             for item in mem::replace(&mut items, Lrc::new(vec![])).iter() {
4109                 if item.ident.name == *segment {
4110                     if path_it.peek().is_none() {
4111                         return match item.def {
4112                             def::Def::Trait(did) => Some(did),
4113                             _ => None,
4114                         }
4115                     }
4116
4117                     items = tcx.item_children(item.def.def_id());
4118                     break;
4119                 }
4120             }
4121         }
4122     } else {
4123         None
4124     }
4125 }
4126
4127 fn get_path_for_type(tcx: TyCtxt, def_id: DefId, def_ctor: fn(DefId) -> Def) -> hir::Path {
4128     struct AbsolutePathBuffer {
4129         names: Vec<String>,
4130     }
4131
4132     impl ty::item_path::ItemPathBuffer for AbsolutePathBuffer {
4133         fn root_mode(&self) -> &ty::item_path::RootMode {
4134             const ABSOLUTE: &'static ty::item_path::RootMode = &ty::item_path::RootMode::Absolute;
4135             ABSOLUTE
4136         }
4137
4138         fn push(&mut self, text: &str) {
4139             self.names.push(text.to_owned());
4140         }
4141     }
4142
4143     let mut apb = AbsolutePathBuffer { names: vec![] };
4144
4145     tcx.push_item_path(&mut apb, def_id);
4146
4147     hir::Path {
4148         span: DUMMY_SP,
4149         def: def_ctor(def_id),
4150         segments: hir::HirVec::from_vec(apb.names.iter().map(|s| hir::PathSegment {
4151             name: ast::Name::intern(&s),
4152             parameters: None,
4153             infer_types: false,
4154         }).collect())
4155     }
4156 }
4157
4158 // End of code copied from rust-clippy
4159
4160
4161 #[derive(Eq, PartialEq, Hash, Copy, Clone, Debug)]
4162 enum RegionTarget<'tcx> {
4163     Region(Region<'tcx>),
4164     RegionVid(RegionVid)
4165 }
4166
4167 #[derive(Default, Debug, Clone)]
4168 struct RegionDeps<'tcx> {
4169     larger: FxHashSet<RegionTarget<'tcx>>,
4170     smaller: FxHashSet<RegionTarget<'tcx>>
4171 }
4172
4173 #[derive(Eq, PartialEq, Hash, Debug)]
4174 enum SimpleBound {
4175     RegionBound(Lifetime),
4176     TraitBound(Vec<PathSegment>, Vec<SimpleBound>, Vec<GenericParam>, hir::TraitBoundModifier)
4177 }
4178
4179 enum AutoTraitResult {
4180     ExplicitImpl,
4181     PositiveImpl(Generics),
4182     NegativeImpl,
4183 }
4184
4185 impl AutoTraitResult {
4186     fn is_auto(&self) -> bool {
4187         match *self {
4188             AutoTraitResult::PositiveImpl(_) | AutoTraitResult::NegativeImpl => true,
4189             _ => false,
4190         }
4191     }
4192 }
4193
4194 impl From<TyParamBound> for SimpleBound {
4195     fn from(bound: TyParamBound) -> Self {
4196         match bound.clone() {
4197             TyParamBound::RegionBound(l) => SimpleBound::RegionBound(l),
4198             TyParamBound::TraitBound(t, mod_) => match t.trait_ {
4199                 Type::ResolvedPath { path, typarams, .. } => {
4200                     SimpleBound::TraitBound(path.segments,
4201                                             typarams
4202                                                 .map_or_else(|| Vec::new(), |v| v.iter()
4203                                                         .map(|p| SimpleBound::from(p.clone()))
4204                                                         .collect()),
4205                                             t.generic_params,
4206                                             mod_)
4207                 }
4208                 _ => panic!("Unexpected bound {:?}", bound),
4209             }
4210         }
4211     }
4212 }