src/librustdoc/clean/utils.rs

   1 use crate::clean::auto_trait::AutoTraitFinder;
   2 use crate::clean::blanket_impl::BlanketImplFinder;
   3 use crate::clean::{
   4     inline, Clean, Crate, Deprecation, ExternalCrate, FnDecl, FnRetTy, Generic, GenericArg,
   5     GenericArgs, GenericBound, Generics, GetDefId, ImportSource, Item, ItemEnum, MacroKind, Path,
   6     PathSegment, Primitive, PrimitiveType, ResolvedPath, Span, Stability, Type, TypeBinding,
   7     TypeKind, Visibility, WherePredicate,
   8 };
   9 use crate::core::DocContext;
  10
  11 use itertools::Itertools;
  12 use rustc_data_structures::fx::FxHashSet;
  13 use rustc_hir as hir;
  14 use rustc_hir::def::{DefKind, Res};
  15 use rustc_hir::def_id::{DefId, LOCAL_CRATE};
  16 use rustc_middle::mir::interpret::{sign_extend, ConstValue, Scalar};
  17 use rustc_middle::ty::subst::{GenericArgKind, SubstsRef};
  18 use rustc_middle::ty::{self, DefIdTree, Ty};
  19 use rustc_span::symbol::{kw, sym, Symbol};
  20 use std::mem;
  21
  22 pub fn krate(mut cx: &mut DocContext<'_>) -> Crate {
  23     use crate::visit_lib::LibEmbargoVisitor;
  24
  25     let krate = cx.tcx.hir().krate();
  26     let module = crate::visit_ast::RustdocVisitor::new(&mut cx).visit(krate);
  27
  28     let mut r = cx.renderinfo.get_mut();
  29     r.deref_trait_did = cx.tcx.lang_items().deref_trait();
  30     r.deref_mut_trait_did = cx.tcx.lang_items().deref_mut_trait();
  31     r.owned_box_did = cx.tcx.lang_items().owned_box();
  32
  33     let mut externs = Vec::new();
  34     for &cnum in cx.tcx.crates().iter() {
  35         externs.push((cnum, cnum.clean(cx)));
  36         // Analyze doc-reachability for extern items
  37         LibEmbargoVisitor::new(&mut cx).visit_lib(cnum);
  38     }
  39     externs.sort_by(|&(a, _), &(b, _)| a.cmp(&b));
  40
  41     // Clean the crate, translating the entire librustc_ast AST to one that is
  42     // understood by rustdoc.
  43     let mut module = module.clean(cx);
  44     let mut masked_crates = FxHashSet::default();
  45
  46     match module.inner {
  47         ItemEnum::ModuleItem(ref module) => {
  48             for it in &module.items {
  49                 // `compiler_builtins` should be masked too, but we can't apply
  50                 // `#[doc(masked)]` to the injected `extern crate` because it's unstable.
  51                 if it.is_extern_crate()
  52                     && (it.attrs.has_doc_flag(sym::masked)
  53                         || cx.tcx.is_compiler_builtins(it.def_id.krate))
  54                 {
  55                     masked_crates.insert(it.def_id.krate);
  56                 }
  57             }
  58         }
  59         _ => unreachable!(),
  60     }
  61
  62     let ExternalCrate { name, src, primitives, keywords, .. } = LOCAL_CRATE.clean(cx);
  63     {
  64         let m = match module.inner {
  65             ItemEnum::ModuleItem(ref mut m) => m,
  66             _ => unreachable!(),
  67         };
  68         m.items.extend(primitives.iter().map(|&(def_id, prim, ref attrs)| Item {
  69             source: Span::empty(),
  70             name: Some(prim.to_url_str().to_string()),
  71             attrs: attrs.clone(),
  72             visibility: Visibility::Public,
  73             stability: get_stability(cx, def_id),
  74             deprecation: get_deprecation(cx, def_id),
  75             def_id,
  76             inner: ItemEnum::PrimitiveItem(prim),
  77         }));
  78         m.items.extend(keywords.into_iter().map(|(def_id, kw, attrs)| Item {
  79             source: Span::empty(),
  80             name: Some(kw.clone()),
  81             attrs,
  82             visibility: Visibility::Public,
  83             stability: get_stability(cx, def_id),
  84             deprecation: get_deprecation(cx, def_id),
  85             def_id,
  86             inner: ItemEnum::KeywordItem(kw),
  87         }));
  88     }
  89
  90     Crate {
  91         name,
  92         version: None,
  93         src,
  94         module: Some(module),
  95         externs,
  96         primitives,
  97         external_traits: cx.external_traits.clone(),
  98         masked_crates,
  99         collapsed: false,
 100     }
 101 }
 102
 103 // extract the stability index for a node from tcx, if possible
 104 pub fn get_stability(cx: &DocContext<'_>, def_id: DefId) -> Option<Stability> {
 105     cx.tcx.lookup_stability(def_id).clean(cx)
 106 }
 107
 108 pub fn get_deprecation(cx: &DocContext<'_>, def_id: DefId) -> Option<Deprecation> {
 109     cx.tcx.lookup_deprecation(def_id).clean(cx)
 110 }
 111
 112 pub fn external_generic_args(
 113     cx: &DocContext<'_>,
 114     trait_did: Option<DefId>,
 115     has_self: bool,
 116     bindings: Vec<TypeBinding>,
 117     substs: SubstsRef<'_>,
 118 ) -> GenericArgs {
 119     let mut skip_self = has_self;
 120     let mut ty_kind = None;
 121     let args: Vec<_> = substs
 122         .iter()
 123         .filter_map(|kind| match kind.unpack() {
 124             GenericArgKind::Lifetime(lt) => lt.clean(cx).map(GenericArg::Lifetime),
 125             GenericArgKind::Type(_) if skip_self => {
 126                 skip_self = false;
 127                 None
 128             }
 129             GenericArgKind::Type(ty) => {
 130                 ty_kind = Some(&ty.kind);
 131                 Some(GenericArg::Type(ty.clean(cx)))
 132             }
 133             GenericArgKind::Const(ct) => Some(GenericArg::Const(ct.clean(cx))),
 134         })
 135         .collect();
 136
 137     match trait_did {
 138         // Attempt to sugar an external path like Fn<(A, B,), C> to Fn(A, B) -> C
 139         Some(did) if cx.tcx.fn_trait_kind_from_lang_item(did).is_some() => {
 140             assert!(ty_kind.is_some());
 141             let inputs = match ty_kind {
 142                 Some(ty::Tuple(ref tys)) => tys.iter().map(|t| t.expect_ty().clean(cx)).collect(),
 143                 _ => return GenericArgs::AngleBracketed { args, bindings },
 144             };
 145             let output = None;
 146             // FIXME(#20299) return type comes from a projection now
 147             // match types[1].kind {
 148             //     ty::Tuple(ref v) if v.is_empty() => None, // -> ()
 149             //     _ => Some(types[1].clean(cx))
 150             // };
 151             GenericArgs::Parenthesized { inputs, output }
 152         }
 153         _ => GenericArgs::AngleBracketed { args, bindings },
 154     }
 155 }
 156
 157 // trait_did should be set to a trait's DefId if called on a TraitRef, in order to sugar
 158 // from Fn<(A, B,), C> to Fn(A, B) -> C
 159 pub fn external_path(
 160     cx: &DocContext<'_>,
 161     name: Symbol,
 162     trait_did: Option<DefId>,
 163     has_self: bool,
 164     bindings: Vec<TypeBinding>,
 165     substs: SubstsRef<'_>,
 166 ) -> Path {
 167     Path {
 168         global: false,
 169         res: Res::Err,
 170         segments: vec![PathSegment {
 171             name: name.to_string(),
 172             args: external_generic_args(cx, trait_did, has_self, bindings, substs),
 173         }],
 174     }
 175 }
 176
 177 /// The point of this function is to replace bounds with types.
 178 ///
 179 /// i.e. `[T, U]` when you have the following bounds: `T: Display, U: Option<T>` will return
 180 /// `[Display, Option]` (we just returns the list of the types, we don't care about the
 181 /// wrapped types in here).
 182 pub fn get_real_types(
 183     generics: &Generics,
 184     arg: &Type,
 185     cx: &DocContext<'_>,
 186     recurse: i32,
 187 ) -> FxHashSet<(Type, TypeKind)> {
 188     let arg_s = arg.print().to_string();
 189     let mut res = FxHashSet::default();
 190     if recurse >= 10 {
 191         // FIXME: remove this whole recurse thing when the recursion bug is fixed
 192         return res;
 193     }
 194     if arg.is_full_generic() {
 195         if let Some(where_pred) = generics.where_predicates.iter().find(|g| match g {
 196             &WherePredicate::BoundPredicate { ref ty, .. } => ty.def_id() == arg.def_id(),
 197             _ => false,
 198         }) {
 199             let bounds = where_pred.get_bounds().unwrap_or_else(|| &[]);
 200             for bound in bounds.iter() {
 201                 if let GenericBound::TraitBound(ref poly_trait, _) = *bound {
 202                     for x in poly_trait.generic_params.iter() {
 203                         if !x.is_type() {
 204                             continue;
 205                         }
 206                         if let Some(ty) = x.get_type() {
 207                             let adds = get_real_types(generics, &ty, cx, recurse + 1);
 208                             if !adds.is_empty() {
 209                                 res.extend(adds);
 210                             } else if !ty.is_full_generic() {
 211                                 if let Some(kind) =
 212                                     ty.def_id().and_then(|did| cx.tcx.def_kind(did).clean(cx))
 213                                 {
 214                                     res.insert((ty, kind));
 215                                 }
 216                             }
 217                         }
 218                     }
 219                 }
 220             }
 221         }
 222         if let Some(bound) = generics.params.iter().find(|g| g.is_type() && g.name == arg_s) {
 223             for bound in bound.get_bounds().unwrap_or_else(|| &[]) {
 224                 if let Some(ty) = bound.get_trait_type() {
 225                     let adds = get_real_types(generics, &ty, cx, recurse + 1);
 226                     if !adds.is_empty() {
 227                         res.extend(adds);
 228                     } else if !ty.is_full_generic() {
 229                         if let Some(kind) =
 230                             ty.def_id().and_then(|did| cx.tcx.def_kind(did).clean(cx))
 231                         {
 232                             res.insert((ty.clone(), kind));
 233                         }
 234                     }
 235                 }
 236             }
 237         }
 238     } else {
 239         if let Some(kind) = arg.def_id().and_then(|did| cx.tcx.def_kind(did).clean(cx)) {
 240             res.insert((arg.clone(), kind));
 241         }
 242         if let Some(gens) = arg.generics() {
 243             for gen in gens.iter() {
 244                 if gen.is_full_generic() {
 245                     let adds = get_real_types(generics, gen, cx, recurse + 1);
 246                     if !adds.is_empty() {
 247                         res.extend(adds);
 248                     }
 249                 } else if let Some(kind) =
 250                     gen.def_id().and_then(|did| cx.tcx.def_kind(did).clean(cx))
 251                 {
 252                     res.insert((gen.clone(), kind));
 253                 }
 254             }
 255         }
 256     }
 257     res
 258 }
 259
 260 /// Return the full list of types when bounds have been resolved.
 261 ///
 262 /// i.e. `fn foo<A: Display, B: Option<A>>(x: u32, y: B)` will return
 263 /// `[u32, Display, Option]`.
 264 pub fn get_all_types(
 265     generics: &Generics,
 266     decl: &FnDecl,
 267     cx: &DocContext<'_>,
 268 ) -> (Vec<(Type, TypeKind)>, Vec<(Type, TypeKind)>) {
 269     let mut all_types = FxHashSet::default();
 270     for arg in decl.inputs.values.iter() {
 271         if arg.type_.is_self_type() {
 272             continue;
 273         }
 274         let args = get_real_types(generics, &arg.type_, cx, 0);
 275         if !args.is_empty() {
 276             all_types.extend(args);
 277         } else {
 278             if let Some(kind) = arg.type_.def_id().and_then(|did| cx.tcx.def_kind(did).clean(cx)) {
 279                 all_types.insert((arg.type_.clone(), kind));
 280             }
 281         }
 282     }
 283
 284     let ret_types = match decl.output {
 285         FnRetTy::Return(ref return_type) => {
 286             let mut ret = get_real_types(generics, &return_type, cx, 0);
 287             if ret.is_empty() {
 288                 if let Some(kind) =
 289                     return_type.def_id().and_then(|did| cx.tcx.def_kind(did).clean(cx))
 290                 {
 291                     ret.insert((return_type.clone(), kind));
 292                 }
 293             }
 294             ret.into_iter().collect()
 295         }
 296         _ => Vec::new(),
 297     };
 298     (all_types.into_iter().collect(), ret_types)
 299 }
 300
 301 pub fn strip_type(ty: Type) -> Type {
 302     match ty {
 303         Type::ResolvedPath { path, param_names, did, is_generic } => {
 304             Type::ResolvedPath { path: strip_path(&path), param_names, did, is_generic }
 305         }
 306         Type::Tuple(inner_tys) => {
 307             Type::Tuple(inner_tys.iter().map(|t| strip_type(t.clone())).collect())
 308         }
 309         Type::Slice(inner_ty) => Type::Slice(Box::new(strip_type(*inner_ty))),
 310         Type::Array(inner_ty, s) => Type::Array(Box::new(strip_type(*inner_ty)), s),
 311         Type::RawPointer(m, inner_ty) => Type::RawPointer(m, Box::new(strip_type(*inner_ty))),
 312         Type::BorrowedRef { lifetime, mutability, type_ } => {
 313             Type::BorrowedRef { lifetime, mutability, type_: Box::new(strip_type(*type_)) }
 314         }
 315         Type::QPath { name, self_type, trait_ } => Type::QPath {
 316             name,
 317             self_type: Box::new(strip_type(*self_type)),
 318             trait_: Box::new(strip_type(*trait_)),
 319         },
 320         _ => ty,
 321     }
 322 }
 323
 324 pub fn strip_path(path: &Path) -> Path {
 325     let segments = path
 326         .segments
 327         .iter()
 328         .map(|s| PathSegment {
 329             name: s.name.clone(),
 330             args: GenericArgs::AngleBracketed { args: vec![], bindings: vec![] },
 331         })
 332         .collect();
 333
 334     Path { global: path.global, res: path.res, segments }
 335 }
 336
 337 pub fn qpath_to_string(p: &hir::QPath) -> String {
 338     let segments = match *p {
 339         hir::QPath::Resolved(_, ref path) => &path.segments,
 340         hir::QPath::TypeRelative(_, ref segment) => return segment.ident.to_string(),
 341     };
 342
 343     let mut s = String::new();
 344     for (i, seg) in segments.iter().enumerate() {
 345         if i > 0 {
 346             s.push_str("::");
 347         }
 348         if seg.ident.name != kw::PathRoot {
 349             s.push_str(&seg.ident.as_str());
 350         }
 351     }
 352     s
 353 }
 354
 355 pub fn build_deref_target_impls(cx: &DocContext<'_>, items: &[Item], ret: &mut Vec<Item>) {
 356     use self::PrimitiveType::*;
 357     let tcx = cx.tcx;
 358
 359     for item in items {
 360         let target = match item.inner {
 361             ItemEnum::TypedefItem(ref t, true) => &t.type_,
 362             _ => continue,
 363         };
 364         let primitive = match *target {
 365             ResolvedPath { did, .. } if did.is_local() => continue,
 366             ResolvedPath { did, .. } => {
 367                 ret.extend(inline::build_impls(cx, did, None));
 368                 continue;
 369             }
 370             _ => match target.primitive_type() {
 371                 Some(prim) => prim,
 372                 None => continue,
 373             },
 374         };
 375         let did = match primitive {
 376             Isize => tcx.lang_items().isize_impl(),
 377             I8 => tcx.lang_items().i8_impl(),
 378             I16 => tcx.lang_items().i16_impl(),
 379             I32 => tcx.lang_items().i32_impl(),
 380             I64 => tcx.lang_items().i64_impl(),
 381             I128 => tcx.lang_items().i128_impl(),
 382             Usize => tcx.lang_items().usize_impl(),
 383             U8 => tcx.lang_items().u8_impl(),
 384             U16 => tcx.lang_items().u16_impl(),
 385             U32 => tcx.lang_items().u32_impl(),
 386             U64 => tcx.lang_items().u64_impl(),
 387             U128 => tcx.lang_items().u128_impl(),
 388             F32 => tcx.lang_items().f32_impl(),
 389             F64 => tcx.lang_items().f64_impl(),
 390             Char => tcx.lang_items().char_impl(),
 391             Bool => tcx.lang_items().bool_impl(),
 392             Str => tcx.lang_items().str_impl(),
 393             Slice => tcx.lang_items().slice_impl(),
 394             Array => tcx.lang_items().slice_impl(),
 395             Tuple => None,
 396             Unit => None,
 397             RawPointer => tcx.lang_items().const_ptr_impl(),
 398             Reference => None,
 399             Fn => None,
 400             Never => None,
 401         };
 402         if let Some(did) = did {
 403             if !did.is_local() {
 404                 inline::build_impl(cx, did, None, ret);
 405             }
 406         }
 407     }
 408 }
 409
 410 pub trait ToSource {
 411     fn to_src(&self, cx: &DocContext<'_>) -> String;
 412 }
 413
 414 impl ToSource for rustc_span::Span {
 415     fn to_src(&self, cx: &DocContext<'_>) -> String {
 416         debug!("converting span {:?} to snippet", self.clean(cx));
 417         let sn = match cx.sess().source_map().span_to_snippet(*self) {
 418             Ok(x) => x,
 419             Err(_) => String::new(),
 420         };
 421         debug!("got snippet {}", sn);
 422         sn
 423     }
 424 }
 425
 426 pub fn name_from_pat(p: &hir::Pat) -> String {
 427     use rustc_hir::*;
 428     debug!("trying to get a name from pattern: {:?}", p);
 429
 430     match p.kind {
 431         PatKind::Wild => "_".to_string(),
 432         PatKind::Binding(_, _, ident, _) => ident.to_string(),
 433         PatKind::TupleStruct(ref p, ..) | PatKind::Path(ref p) => qpath_to_string(p),
 434         PatKind::Struct(ref name, ref fields, etc) => format!(
 435             "{} {{ {}{} }}",
 436             qpath_to_string(name),
 437             fields
 438                 .iter()
 439                 .map(|fp| format!("{}: {}", fp.ident, name_from_pat(&fp.pat)))
 440                 .collect::<Vec<String>>()
 441                 .join(", "),
 442             if etc { ", .." } else { "" }
 443         ),
 444         PatKind::Or(ref pats) => {
 445             pats.iter().map(|p| name_from_pat(&**p)).collect::<Vec<String>>().join(" | ")
 446         }
 447         PatKind::Tuple(ref elts, _) => format!(
 448             "({})",
 449             elts.iter().map(|p| name_from_pat(&**p)).collect::<Vec<String>>().join(", ")
 450         ),
 451         PatKind::Box(ref p) => name_from_pat(&**p),
 452         PatKind::Ref(ref p, _) => name_from_pat(&**p),
 453         PatKind::Lit(..) => {
 454             warn!(
 455                 "tried to get argument name from PatKind::Lit, \
 456                   which is silly in function arguments"
 457             );
 458             "()".to_string()
 459         }
 460         PatKind::Range(..) => panic!(
 461             "tried to get argument name from PatKind::Range, \
 462                               which is not allowed in function arguments"
 463         ),
 464         PatKind::Slice(ref begin, ref mid, ref end) => {
 465             let begin = begin.iter().map(|p| name_from_pat(&**p));
 466             let mid = mid.as_ref().map(|p| format!("..{}", name_from_pat(&**p))).into_iter();
 467             let end = end.iter().map(|p| name_from_pat(&**p));
 468             format!("[{}]", begin.chain(mid).chain(end).collect::<Vec<_>>().join(", "))
 469         }
 470     }
 471 }
 472
 473 pub fn print_const(cx: &DocContext<'_>, n: &'tcx ty::Const<'_>) -> String {
 474     match n.val {
 475         ty::ConstKind::Unevaluated(def_id, _, promoted) => {
 476             let mut s = if let Some(hir_id) = cx.tcx.hir().as_local_hir_id(def_id) {
 477                 print_const_expr(cx, cx.tcx.hir().body_owned_by(hir_id))
 478             } else {
 479                 inline::print_inlined_const(cx, def_id)
 480             };
 481             if let Some(promoted) = promoted {
 482                 s.push_str(&format!("::{:?}", promoted))
 483             }
 484             s
 485         }
 486         _ => {
 487             let mut s = n.to_string();
 488             // array lengths are obviously usize
 489             if s.ends_with("usize") {
 490                 let n = s.len() - "usize".len();
 491                 s.truncate(n);
 492                 if s.ends_with(": ") {
 493                     let n = s.len() - ": ".len();
 494                     s.truncate(n);
 495                 }
 496             }
 497             s
 498         }
 499     }
 500 }
 501
 502 pub fn print_evaluated_const(cx: &DocContext<'_>, def_id: DefId) -> Option<String> {
 503     cx.tcx.const_eval_poly(def_id).ok().and_then(|val| {
 504         let ty = cx.tcx.type_of(def_id);
 505         match (val, &ty.kind) {
 506             (_, &ty::Ref(..)) => None,
 507             (ConstValue::Scalar(_), &ty::Adt(_, _)) => None,
 508             (ConstValue::Scalar(_), _) => {
 509                 let const_ = ty::Const::from_value(cx.tcx, val, ty);
 510                 Some(print_const_with_custom_print_scalar(cx, const_))
 511             }
 512             _ => None,
 513         }
 514     })
 515 }
 516
 517 fn format_integer_with_underscore_sep(num: &str) -> String {
 518     let num_chars: Vec<_> = num.chars().collect();
 519     let num_start_index = if num_chars.get(0) == Some(&'-') { 1 } else { 0 };
 520
 521     num_chars[..num_start_index]
 522         .iter()
 523         .chain(num_chars[num_start_index..].rchunks(3).rev().intersperse(&['_']).flatten())
 524         .collect()
 525 }
 526
 527 fn print_const_with_custom_print_scalar(cx: &DocContext<'_>, ct: &'tcx ty::Const<'tcx>) -> String {
 528     // Use a slightly different format for integer types which always shows the actual value.
 529     // For all other types, fallback to the original `pretty_print_const`.
 530     match (ct.val, &ct.ty.kind) {
 531         (ty::ConstKind::Value(ConstValue::Scalar(Scalar::Raw { data, .. })), ty::Uint(ui)) => {
 532             format!("{}{}", format_integer_with_underscore_sep(&data.to_string()), ui.name_str())
 533         }
 534         (ty::ConstKind::Value(ConstValue::Scalar(Scalar::Raw { data, .. })), ty::Int(i)) => {
 535             let ty = cx.tcx.lift(&ct.ty).unwrap();
 536             let size = cx.tcx.layout_of(ty::ParamEnv::empty().and(ty)).unwrap().size;
 537             let sign_extended_data = sign_extend(data, size) as i128;
 538
 539             format!(
 540                 "{}{}",
 541                 format_integer_with_underscore_sep(&sign_extended_data.to_string()),
 542                 i.name_str()
 543             )
 544         }
 545         _ => ct.to_string(),
 546     }
 547 }
 548
 549 pub fn is_literal_expr(cx: &DocContext<'_>, hir_id: hir::HirId) -> bool {
 550     if let hir::Node::Expr(expr) = cx.tcx.hir().get(hir_id) {
 551         if let hir::ExprKind::Lit(_) = &expr.kind {
 552             return true;
 553         }
 554
 555         if let hir::ExprKind::Unary(hir::UnOp::UnNeg, expr) = &expr.kind {
 556             if let hir::ExprKind::Lit(_) = &expr.kind {
 557                 return true;
 558             }
 559         }
 560     }
 561
 562     false
 563 }
 564
 565 pub fn print_const_expr(cx: &DocContext<'_>, body: hir::BodyId) -> String {
 566     let value = &cx.tcx.hir().body(body).value;
 567
 568     let snippet = if !value.span.from_expansion() {
 569         cx.sess().source_map().span_to_snippet(value.span).ok()
 570     } else {
 571         None
 572     };
 573
 574     snippet.unwrap_or_else(|| rustc_hir_pretty::id_to_string(&cx.tcx.hir(), body.hir_id))
 575 }
 576
 577 /// Given a type Path, resolve it to a Type using the TyCtxt
 578 pub fn resolve_type(cx: &DocContext<'_>, path: Path, id: hir::HirId) -> Type {
 579     debug!("resolve_type({:?},{:?})", path, id);
 580
 581     let is_generic = match path.res {
 582         Res::PrimTy(p) => return Primitive(PrimitiveType::from(p)),
 583         Res::SelfTy(..) if path.segments.len() == 1 => {
 584             return Generic(kw::SelfUpper.to_string());
 585         }
 586         Res::Def(DefKind::TyParam, _) if path.segments.len() == 1 => {
 587             return Generic(format!("{:#}", path.print()));
 588         }
 589         Res::SelfTy(..) | Res::Def(DefKind::TyParam | DefKind::AssocTy, _) => true,
 590         _ => false,
 591     };
 592     let did = register_res(&*cx, path.res);
 593     ResolvedPath { path, param_names: None, did, is_generic }
 594 }
 595
 596 pub fn get_auto_trait_and_blanket_impls(
 597     cx: &DocContext<'tcx>,
 598     ty: Ty<'tcx>,
 599     param_env_def_id: DefId,
 600 ) -> impl Iterator<Item = Item> {
 601     AutoTraitFinder::new(cx)
 602         .get_auto_trait_impls(ty, param_env_def_id)
 603         .into_iter()
 604         .chain(BlanketImplFinder::new(cx).get_blanket_impls(ty, param_env_def_id))
 605 }
 606
 607 pub fn register_res(cx: &DocContext<'_>, res: Res) -> DefId {
 608     debug!("register_res({:?})", res);
 609
 610     let (did, kind) = match res {
 611         Res::Def(DefKind::Fn, i) => (i, TypeKind::Function),
 612         Res::Def(DefKind::TyAlias, i) => (i, TypeKind::Typedef),
 613         Res::Def(DefKind::Enum, i) => (i, TypeKind::Enum),
 614         Res::Def(DefKind::Trait, i) => (i, TypeKind::Trait),
 615         Res::Def(DefKind::Struct, i) => (i, TypeKind::Struct),
 616         Res::Def(DefKind::Union, i) => (i, TypeKind::Union),
 617         Res::Def(DefKind::Mod, i) => (i, TypeKind::Module),
 618         Res::Def(DefKind::ForeignTy, i) => (i, TypeKind::Foreign),
 619         Res::Def(DefKind::Const, i) => (i, TypeKind::Const),
 620         Res::Def(DefKind::Static, i) => (i, TypeKind::Static),
 621         Res::Def(DefKind::Variant, i) => {
 622             (cx.tcx.parent(i).expect("cannot get parent def id"), TypeKind::Enum)
 623         }
 624         Res::Def(DefKind::Macro(mac_kind), i) => match mac_kind {
 625             MacroKind::Bang => (i, TypeKind::Macro),
 626             MacroKind::Attr => (i, TypeKind::Attr),
 627             MacroKind::Derive => (i, TypeKind::Derive),
 628         },
 629         Res::Def(DefKind::TraitAlias, i) => (i, TypeKind::TraitAlias),
 630         Res::SelfTy(Some(def_id), _) => (def_id, TypeKind::Trait),
 631         Res::SelfTy(_, Some(impl_def_id)) => return impl_def_id,
 632         _ => return res.def_id(),
 633     };
 634     if did.is_local() {
 635         return did;
 636     }
 637     inline::record_extern_fqn(cx, did, kind);
 638     if let TypeKind::Trait = kind {
 639         inline::record_extern_trait(cx, did);
 640     }
 641     did
 642 }
 643
 644 pub fn resolve_use_source(cx: &DocContext<'_>, path: Path) -> ImportSource {
 645     ImportSource {
 646         did: if path.res.opt_def_id().is_none() { None } else { Some(register_res(cx, path.res)) },
 647         path,
 648     }
 649 }
 650
 651 pub fn enter_impl_trait<F, R>(cx: &DocContext<'_>, f: F) -> R
 652 where
 653     F: FnOnce() -> R,
 654 {
 655     let old_bounds = mem::take(&mut *cx.impl_trait_bounds.borrow_mut());
 656     let r = f();
 657     assert!(cx.impl_trait_bounds.borrow().is_empty());
 658     *cx.impl_trait_bounds.borrow_mut() = old_bounds;
 659     r
 660 }