src/librustdoc/clean/inline.rs

   1 //! Support for inlining external documentation into the current AST.
   2
   3 use std::iter::once;
   4 use std::sync::Arc;
   5
   6 use thin_vec::ThinVec;
   7
   8 use rustc_ast as ast;
   9 use rustc_data_structures::fx::FxHashSet;
  10 use rustc_hir as hir;
  11 use rustc_hir::def::{DefKind, Res};
  12 use rustc_hir::def_id::DefId;
  13 use rustc_hir::Mutability;
  14 use rustc_metadata::creader::{CStore, LoadedMacro};
  15 use rustc_middle::ty::{self, TyCtxt};
  16 use rustc_span::hygiene::MacroKind;
  17 use rustc_span::symbol::{kw, sym, Symbol};
  18
  19 use crate::clean::{
  20     self, clean_fn_decl_from_did_and_sig, clean_generics, clean_impl_item, clean_middle_assoc_item,
  21     clean_middle_field, clean_middle_ty, clean_trait_ref_with_bindings, clean_ty,
  22     clean_ty_generics, clean_variant_def, clean_visibility, utils, Attributes, AttributesExt,
  23     ImplKind, ItemId, Type, Visibility,
  24 };
  25 use crate::core::DocContext;
  26 use crate::formats::item_type::ItemType;
  27
  28 /// Attempt to inline a definition into this AST.
  29 ///
  30 /// This function will fetch the definition specified, and if it is
  31 /// from another crate it will attempt to inline the documentation
  32 /// from the other crate into this crate.
  33 ///
  34 /// This is primarily used for `pub use` statements which are, in general,
  35 /// implementation details. Inlining the documentation should help provide a
  36 /// better experience when reading the documentation in this use case.
  37 ///
  38 /// The returned value is `None` if the definition could not be inlined,
  39 /// and `Some` of a vector of items if it was successfully expanded.
  40 ///
  41 /// `parent_module` refers to the parent of the *re-export*, not the original item.
  42 pub(crate) fn try_inline(
  43     cx: &mut DocContext<'_>,
  44     parent_module: DefId,
  45     import_def_id: Option<DefId>,
  46     res: Res,
  47     name: Symbol,
  48     attrs: Option<&[ast::Attribute]>,
  49     visited: &mut FxHashSet<DefId>,
  50 ) -> Option<Vec<clean::Item>> {
  51     let did = res.opt_def_id()?;
  52     if did.is_local() {
  53         return None;
  54     }
  55     let mut ret = Vec::new();
  56
  57     debug!("attrs={:?}", attrs);
  58     let attrs_clone = attrs;
  59
  60     let kind = match res {
  61         Res::Def(DefKind::Trait, did) => {
  62             record_extern_fqn(cx, did, ItemType::Trait);
  63             build_impls(cx, Some(parent_module), did, attrs, &mut ret);
  64             clean::TraitItem(Box::new(build_external_trait(cx, did)))
  65         }
  66         Res::Def(DefKind::Fn, did) => {
  67             record_extern_fqn(cx, did, ItemType::Function);
  68             clean::FunctionItem(build_external_function(cx, did))
  69         }
  70         Res::Def(DefKind::Struct, did) => {
  71             record_extern_fqn(cx, did, ItemType::Struct);
  72             build_impls(cx, Some(parent_module), did, attrs, &mut ret);
  73             clean::StructItem(build_struct(cx, did))
  74         }
  75         Res::Def(DefKind::Union, did) => {
  76             record_extern_fqn(cx, did, ItemType::Union);
  77             build_impls(cx, Some(parent_module), did, attrs, &mut ret);
  78             clean::UnionItem(build_union(cx, did))
  79         }
  80         Res::Def(DefKind::TyAlias, did) => {
  81             record_extern_fqn(cx, did, ItemType::Typedef);
  82             build_impls(cx, Some(parent_module), did, attrs, &mut ret);
  83             clean::TypedefItem(build_type_alias(cx, did))
  84         }
  85         Res::Def(DefKind::Enum, did) => {
  86             record_extern_fqn(cx, did, ItemType::Enum);
  87             build_impls(cx, Some(parent_module), did, attrs, &mut ret);
  88             clean::EnumItem(build_enum(cx, did))
  89         }
  90         Res::Def(DefKind::ForeignTy, did) => {
  91             record_extern_fqn(cx, did, ItemType::ForeignType);
  92             build_impls(cx, Some(parent_module), did, attrs, &mut ret);
  93             clean::ForeignTypeItem
  94         }
  95         // Never inline enum variants but leave them shown as re-exports.
  96         Res::Def(DefKind::Variant, _) => return None,
  97         // Assume that enum variants and struct types are re-exported next to
  98         // their constructors.
  99         Res::Def(DefKind::Ctor(..), _) | Res::SelfCtor(..) => return Some(Vec::new()),
 100         Res::Def(DefKind::Mod, did) => {
 101             record_extern_fqn(cx, did, ItemType::Module);
 102             clean::ModuleItem(build_module(cx, did, visited))
 103         }
 104         Res::Def(DefKind::Static(_), did) => {
 105             record_extern_fqn(cx, did, ItemType::Static);
 106             clean::StaticItem(build_static(cx, did, cx.tcx.is_mutable_static(did)))
 107         }
 108         Res::Def(DefKind::Const, did) => {
 109             record_extern_fqn(cx, did, ItemType::Constant);
 110             clean::ConstantItem(build_const(cx, did))
 111         }
 112         Res::Def(DefKind::Macro(kind), did) => {
 113             let mac = build_macro(cx, did, name, import_def_id);
 114
 115             let type_kind = match kind {
 116                 MacroKind::Bang => ItemType::Macro,
 117                 MacroKind::Attr => ItemType::ProcAttribute,
 118                 MacroKind::Derive => ItemType::ProcDerive,
 119             };
 120             record_extern_fqn(cx, did, type_kind);
 121             mac
 122         }
 123         _ => return None,
 124     };
 125
 126     let (attrs, cfg) = merge_attrs(cx, Some(parent_module), load_attrs(cx, did), attrs_clone);
 127     cx.inlined.insert(did.into());
 128     let mut item = clean::Item::from_def_id_and_attrs_and_parts(
 129         did,
 130         Some(name),
 131         kind,
 132         Box::new(attrs),
 133         cx,
 134         cfg,
 135     );
 136     if let Some(import_def_id) = import_def_id {
 137         // The visibility needs to reflect the one from the reexport and not from the "source" DefId.
 138         item.visibility = clean_visibility(cx.tcx.visibility(import_def_id));
 139     }
 140     ret.push(item);
 141     Some(ret)
 142 }
 143
 144 pub(crate) fn try_inline_glob(
 145     cx: &mut DocContext<'_>,
 146     res: Res,
 147     visited: &mut FxHashSet<DefId>,
 148     inlined_names: &mut FxHashSet<(ItemType, Symbol)>,
 149 ) -> Option<Vec<clean::Item>> {
 150     let did = res.opt_def_id()?;
 151     if did.is_local() {
 152         return None;
 153     }
 154
 155     match res {
 156         Res::Def(DefKind::Mod, did) => {
 157             let mut items = build_module_items(cx, did, visited, inlined_names);
 158             items.drain_filter(|item| {
 159                 if let Some(name) = item.name {
 160                     // If an item with the same type and name already exists,
 161                     // it takes priority over the inlined stuff.
 162                     !inlined_names.insert((item.type_(), name))
 163                 } else {
 164                     false
 165                 }
 166             });
 167             Some(items)
 168         }
 169         // glob imports on things like enums aren't inlined even for local exports, so just bail
 170         _ => None,
 171     }
 172 }
 173
 174 pub(crate) fn load_attrs<'hir>(cx: &DocContext<'hir>, did: DefId) -> &'hir [ast::Attribute] {
 175     cx.tcx.get_attrs_unchecked(did)
 176 }
 177
 178 /// Record an external fully qualified name in the external_paths cache.
 179 ///
 180 /// These names are used later on by HTML rendering to generate things like
 181 /// source links back to the original item.
 182 pub(crate) fn record_extern_fqn(cx: &mut DocContext<'_>, did: DefId, kind: ItemType) {
 183     let crate_name = cx.tcx.crate_name(did.krate);
 184
 185     let relative =
 186         cx.tcx.def_path(did).data.into_iter().filter_map(|elem| elem.data.get_opt_name());
 187     let fqn = if let ItemType::Macro = kind {
 188         // Check to see if it is a macro 2.0 or built-in macro
 189         if matches!(
 190             CStore::from_tcx(cx.tcx).load_macro_untracked(did, cx.sess()),
 191             LoadedMacro::MacroDef(def, _)
 192                 if matches!(&def.kind, ast::ItemKind::MacroDef(ast_def)
 193                     if !ast_def.macro_rules)
 194         ) {
 195             once(crate_name).chain(relative).collect()
 196         } else {
 197             vec![crate_name, relative.last().expect("relative was empty")]
 198         }
 199     } else {
 200         once(crate_name).chain(relative).collect()
 201     };
 202
 203     if did.is_local() {
 204         cx.cache.exact_paths.insert(did, fqn);
 205     } else {
 206         cx.cache.external_paths.insert(did, (fqn, kind));
 207     }
 208 }
 209
 210 pub(crate) fn build_external_trait(cx: &mut DocContext<'_>, did: DefId) -> clean::Trait {
 211     let trait_items = cx
 212         .tcx
 213         .associated_items(did)
 214         .in_definition_order()
 215         .map(|item| {
 216             // When building an external trait, the cleaned trait will have all items public,
 217             // which causes methods to have a `pub` prefix, which is invalid since items in traits
 218             // can not have a visibility prefix. Thus we override the visibility here manually.
 219             // See https://github.com/rust-lang/rust/issues/81274
 220             clean::Item { visibility: Visibility::Inherited, ..clean_middle_assoc_item(item, cx) }
 221         })
 222         .collect();
 223
 224     let predicates = cx.tcx.predicates_of(did);
 225     let generics = clean_ty_generics(cx, cx.tcx.generics_of(did), predicates);
 226     let generics = filter_non_trait_generics(did, generics);
 227     let (generics, supertrait_bounds) = separate_supertrait_bounds(generics);
 228     clean::Trait { def_id: did, generics, items: trait_items, bounds: supertrait_bounds }
 229 }
 230
 231 fn build_external_function<'tcx>(cx: &mut DocContext<'tcx>, did: DefId) -> Box<clean::Function> {
 232     let sig = cx.tcx.fn_sig(did);
 233
 234     let predicates = cx.tcx.predicates_of(did);
 235     let (generics, decl) = clean::enter_impl_trait(cx, |cx| {
 236         // NOTE: generics need to be cleaned before the decl!
 237         let generics = clean_ty_generics(cx, cx.tcx.generics_of(did), predicates);
 238         let decl = clean_fn_decl_from_did_and_sig(cx, Some(did), sig);
 239         (generics, decl)
 240     });
 241     Box::new(clean::Function { decl, generics })
 242 }
 243
 244 fn build_enum(cx: &mut DocContext<'_>, did: DefId) -> clean::Enum {
 245     let predicates = cx.tcx.explicit_predicates_of(did);
 246
 247     clean::Enum {
 248         generics: clean_ty_generics(cx, cx.tcx.generics_of(did), predicates),
 249         variants: cx.tcx.adt_def(did).variants().iter().map(|v| clean_variant_def(v, cx)).collect(),
 250     }
 251 }
 252
 253 fn build_struct(cx: &mut DocContext<'_>, did: DefId) -> clean::Struct {
 254     let predicates = cx.tcx.explicit_predicates_of(did);
 255     let variant = cx.tcx.adt_def(did).non_enum_variant();
 256
 257     clean::Struct {
 258         struct_type: variant.ctor_kind,
 259         generics: clean_ty_generics(cx, cx.tcx.generics_of(did), predicates),
 260         fields: variant.fields.iter().map(|x| clean_middle_field(x, cx)).collect(),
 261     }
 262 }
 263
 264 fn build_union(cx: &mut DocContext<'_>, did: DefId) -> clean::Union {
 265     let predicates = cx.tcx.explicit_predicates_of(did);
 266     let variant = cx.tcx.adt_def(did).non_enum_variant();
 267
 268     let generics = clean_ty_generics(cx, cx.tcx.generics_of(did), predicates);
 269     let fields = variant.fields.iter().map(|x| clean_middle_field(x, cx)).collect();
 270     clean::Union { generics, fields }
 271 }
 272
 273 fn build_type_alias(cx: &mut DocContext<'_>, did: DefId) -> Box<clean::Typedef> {
 274     let predicates = cx.tcx.explicit_predicates_of(did);
 275     let type_ = clean_middle_ty(cx.tcx.type_of(did), cx, Some(did));
 276
 277     Box::new(clean::Typedef {
 278         type_,
 279         generics: clean_ty_generics(cx, cx.tcx.generics_of(did), predicates),
 280         item_type: None,
 281     })
 282 }
 283
 284 /// Builds all inherent implementations of an ADT (struct/union/enum) or Trait item/path/reexport.
 285 pub(crate) fn build_impls(
 286     cx: &mut DocContext<'_>,
 287     parent_module: Option<DefId>,
 288     did: DefId,
 289     attrs: Option<&[ast::Attribute]>,
 290     ret: &mut Vec<clean::Item>,
 291 ) {
 292     let _prof_timer = cx.tcx.sess.prof.generic_activity("build_inherent_impls");
 293     let tcx = cx.tcx;
 294
 295     // for each implementation of an item represented by `did`, build the clean::Item for that impl
 296     for &did in tcx.inherent_impls(did).iter() {
 297         build_impl(cx, parent_module, did, attrs, ret);
 298     }
 299
 300     // This pretty much exists expressly for `dyn Error` traits that exist in the `alloc` crate.
 301     // See also:
 302     //
 303     // * https://github.com/rust-lang/rust/issues/103170 — where it didn't used to get documented
 304     // * https://github.com/rust-lang/rust/pull/99917 — where the feature got used
 305     // * https://github.com/rust-lang/rust/issues/53487 — overall tracking issue for Error
 306     if tcx.has_attr(did, sym::rustc_has_incoherent_inherent_impls) {
 307         use rustc_middle::ty::fast_reject::SimplifiedTypeGen::*;
 308         let type_ =
 309             if tcx.is_trait(did) { TraitSimplifiedType(did) } else { AdtSimplifiedType(did) };
 310         for &did in tcx.incoherent_impls(type_) {
 311             build_impl(cx, parent_module, did, attrs, ret);
 312         }
 313     }
 314 }
 315
 316 /// `parent_module` refers to the parent of the re-export, not the original item
 317 pub(crate) fn merge_attrs(
 318     cx: &mut DocContext<'_>,
 319     parent_module: Option<DefId>,
 320     old_attrs: &[ast::Attribute],
 321     new_attrs: Option<&[ast::Attribute]>,
 322 ) -> (clean::Attributes, Option<Arc<clean::cfg::Cfg>>) {
 323     // NOTE: If we have additional attributes (from a re-export),
 324     // always insert them first. This ensure that re-export
 325     // doc comments show up before the original doc comments
 326     // when we render them.
 327     if let Some(inner) = new_attrs {
 328         let mut both = inner.to_vec();
 329         both.extend_from_slice(old_attrs);
 330         (
 331             if let Some(new_id) = parent_module {
 332                 Attributes::from_ast_with_additional(old_attrs, (inner, new_id))
 333             } else {
 334                 Attributes::from_ast(&both)
 335             },
 336             both.cfg(cx.tcx, &cx.cache.hidden_cfg),
 337         )
 338     } else {
 339         (Attributes::from_ast(&old_attrs), old_attrs.cfg(cx.tcx, &cx.cache.hidden_cfg))
 340     }
 341 }
 342
 343 /// Inline an `impl`, inherent or of a trait. The `did` must be for an `impl`.
 344 pub(crate) fn build_impl(
 345     cx: &mut DocContext<'_>,
 346     parent_module: Option<DefId>,
 347     did: DefId,
 348     attrs: Option<&[ast::Attribute]>,
 349     ret: &mut Vec<clean::Item>,
 350 ) {
 351     if !cx.inlined.insert(did.into()) {
 352         return;
 353     }
 354
 355     let _prof_timer = cx.tcx.sess.prof.generic_activity("build_impl");
 356
 357     let tcx = cx.tcx;
 358     let associated_trait = tcx.impl_trait_ref(did);
 359
 360     // Only inline impl if the implemented trait is
 361     // reachable in rustdoc generated documentation
 362     if !did.is_local() {
 363         if let Some(traitref) = associated_trait {
 364             let did = traitref.def_id;
 365             if !cx.cache.access_levels.is_public(did) {
 366                 return;
 367             }
 368
 369             if let Some(stab) = tcx.lookup_stability(did) {
 370                 if stab.is_unstable() && stab.feature == sym::rustc_private {
 371                     return;
 372                 }
 373             }
 374         }
 375     }
 376
 377     let impl_item = match did.as_local() {
 378         Some(did) => match &tcx.hir().expect_item(did).kind {
 379             hir::ItemKind::Impl(impl_) => Some(impl_),
 380             _ => panic!("`DefID` passed to `build_impl` is not an `impl"),
 381         },
 382         None => None,
 383     };
 384
 385     let for_ = match &impl_item {
 386         Some(impl_) => clean_ty(impl_.self_ty, cx),
 387         None => clean_middle_ty(tcx.type_of(did), cx, Some(did)),
 388     };
 389
 390     // Only inline impl if the implementing type is
 391     // reachable in rustdoc generated documentation
 392     if !did.is_local() {
 393         if let Some(did) = for_.def_id(&cx.cache) {
 394             if !cx.cache.access_levels.is_public(did) {
 395                 return;
 396             }
 397
 398             if let Some(stab) = tcx.lookup_stability(did) {
 399                 if stab.is_unstable() && stab.feature == sym::rustc_private {
 400                     return;
 401                 }
 402             }
 403         }
 404     }
 405
 406     let document_hidden = cx.render_options.document_hidden;
 407     let predicates = tcx.explicit_predicates_of(did);
 408     let (trait_items, generics) = match impl_item {
 409         Some(impl_) => (
 410             impl_
 411                 .items
 412                 .iter()
 413                 .map(|item| tcx.hir().impl_item(item.id))
 414                 .filter(|item| {
 415                     // Filter out impl items whose corresponding trait item has `doc(hidden)`
 416                     // not to document such impl items.
 417                     // For inherent impls, we don't do any filtering, because that's already done in strip_hidden.rs.
 418
 419                     // When `--document-hidden-items` is passed, we don't
 420                     // do any filtering, too.
 421                     if document_hidden {
 422                         return true;
 423                     }
 424                     if let Some(associated_trait) = associated_trait {
 425                         let assoc_kind = match item.kind {
 426                             hir::ImplItemKind::Const(..) => ty::AssocKind::Const,
 427                             hir::ImplItemKind::Fn(..) => ty::AssocKind::Fn,
 428                             hir::ImplItemKind::TyAlias(..) => ty::AssocKind::Type,
 429                         };
 430                         let trait_item = tcx
 431                             .associated_items(associated_trait.def_id)
 432                             .find_by_name_and_kind(
 433                                 tcx,
 434                                 item.ident,
 435                                 assoc_kind,
 436                                 associated_trait.def_id,
 437                             )
 438                             .unwrap(); // SAFETY: For all impl items there exists trait item that has the same name.
 439                         !tcx.is_doc_hidden(trait_item.def_id)
 440                     } else {
 441                         true
 442                     }
 443                 })
 444                 .map(|item| clean_impl_item(item, cx))
 445                 .collect::<Vec<_>>(),
 446             clean_generics(impl_.generics, cx),
 447         ),
 448         None => (
 449             tcx.associated_items(did)
 450                 .in_definition_order()
 451                 .filter(|item| {
 452                     // If this is a trait impl, filter out associated items whose corresponding item
 453                     // in the associated trait is marked `doc(hidden)`.
 454                     // If this is an inherent impl, filter out private associated items.
 455                     if let Some(associated_trait) = associated_trait {
 456                         let trait_item = tcx
 457                             .associated_items(associated_trait.def_id)
 458                             .find_by_name_and_kind(
 459                                 tcx,
 460                                 item.ident(tcx),
 461                                 item.kind,
 462                                 associated_trait.def_id,
 463                             )
 464                             .unwrap(); // corresponding associated item has to exist
 465                         !tcx.is_doc_hidden(trait_item.def_id)
 466                     } else {
 467                         item.visibility(tcx).is_public()
 468                     }
 469                 })
 470                 .map(|item| clean_middle_assoc_item(item, cx))
 471                 .collect::<Vec<_>>(),
 472             clean::enter_impl_trait(cx, |cx| {
 473                 clean_ty_generics(cx, tcx.generics_of(did), predicates)
 474             }),
 475         ),
 476     };
 477     let polarity = tcx.impl_polarity(did);
 478     let trait_ = associated_trait.map(|t| clean_trait_ref_with_bindings(cx, t, ThinVec::new()));
 479     if trait_.as_ref().map(|t| t.def_id()) == tcx.lang_items().deref_trait() {
 480         super::build_deref_target_impls(cx, &trait_items, ret);
 481     }
 482
 483     // Return if the trait itself or any types of the generic parameters are doc(hidden).
 484     let mut stack: Vec<&Type> = vec![&for_];
 485
 486     if let Some(did) = trait_.as_ref().map(|t| t.def_id()) {
 487         if tcx.is_doc_hidden(did) {
 488             return;
 489         }
 490     }
 491     if let Some(generics) = trait_.as_ref().and_then(|t| t.generics()) {
 492         stack.extend(generics);
 493     }
 494
 495     while let Some(ty) = stack.pop() {
 496         if let Some(did) = ty.def_id(&cx.cache) {
 497             if tcx.is_doc_hidden(did) {
 498                 return;
 499             }
 500         }
 501         if let Some(generics) = ty.generics() {
 502             stack.extend(generics);
 503         }
 504     }
 505
 506     if let Some(did) = trait_.as_ref().map(|t| t.def_id()) {
 507         record_extern_trait(cx, did);
 508     }
 509
 510     let (merged_attrs, cfg) = merge_attrs(cx, parent_module, load_attrs(cx, did), attrs);
 511     trace!("merged_attrs={:?}", merged_attrs);
 512
 513     trace!(
 514         "build_impl: impl {:?} for {:?}",
 515         trait_.as_ref().map(|t| t.def_id()),
 516         for_.def_id(&cx.cache)
 517     );
 518     ret.push(clean::Item::from_def_id_and_attrs_and_parts(
 519         did,
 520         None,
 521         clean::ImplItem(Box::new(clean::Impl {
 522             unsafety: hir::Unsafety::Normal,
 523             generics,
 524             trait_,
 525             for_,
 526             items: trait_items,
 527             polarity,
 528             kind: if utils::has_doc_flag(tcx, did, sym::fake_variadic) {
 529                 ImplKind::FakeVaradic
 530             } else {
 531                 ImplKind::Normal
 532             },
 533         })),
 534         Box::new(merged_attrs),
 535         cx,
 536         cfg,
 537     ));
 538 }
 539
 540 fn build_module(
 541     cx: &mut DocContext<'_>,
 542     did: DefId,
 543     visited: &mut FxHashSet<DefId>,
 544 ) -> clean::Module {
 545     let items = build_module_items(cx, did, visited, &mut FxHashSet::default());
 546
 547     let span = clean::Span::new(cx.tcx.def_span(did));
 548     clean::Module { items, span }
 549 }
 550
 551 fn build_module_items(
 552     cx: &mut DocContext<'_>,
 553     did: DefId,
 554     visited: &mut FxHashSet<DefId>,
 555     inlined_names: &mut FxHashSet<(ItemType, Symbol)>,
 556 ) -> Vec<clean::Item> {
 557     let mut items = Vec::new();
 558
 559     // If we're re-exporting a re-export it may actually re-export something in
 560     // two namespaces, so the target may be listed twice. Make sure we only
 561     // visit each node at most once.
 562     for &item in cx.tcx.module_children(did).iter() {
 563         if item.vis.is_public() {
 564             let res = item.res.expect_non_local();
 565             if let Some(def_id) = res.mod_def_id() {
 566                 // If we're inlining a glob import, it's possible to have
 567                 // two distinct modules with the same name. We don't want to
 568                 // inline it, or mark any of its contents as visited.
 569                 if did == def_id
 570                     || inlined_names.contains(&(ItemType::Module, item.ident.name))
 571                     || !visited.insert(def_id)
 572                 {
 573                     continue;
 574                 }
 575             }
 576             if let Res::PrimTy(p) = res {
 577                 // Primitive types can't be inlined so generate an import instead.
 578                 let prim_ty = clean::PrimitiveType::from(p);
 579                 items.push(clean::Item {
 580                     name: None,
 581                     attrs: Box::new(clean::Attributes::default()),
 582                     item_id: ItemId::Primitive(prim_ty, did.krate),
 583                     visibility: clean::Public,
 584                     kind: Box::new(clean::ImportItem(clean::Import::new_simple(
 585                         item.ident.name,
 586                         clean::ImportSource {
 587                             path: clean::Path {
 588                                 res,
 589                                 segments: vec![clean::PathSegment {
 590                                     name: prim_ty.as_sym(),
 591                                     args: clean::GenericArgs::AngleBracketed {
 592                                         args: Default::default(),
 593                                         bindings: ThinVec::new(),
 594                                     },
 595                                 }],
 596                             },
 597                             did: None,
 598                         },
 599                         true,
 600                     ))),
 601                     cfg: None,
 602                 });
 603             } else if let Some(i) = try_inline(cx, did, None, res, item.ident.name, None, visited) {
 604                 items.extend(i)
 605             }
 606         }
 607     }
 608
 609     items
 610 }
 611
 612 pub(crate) fn print_inlined_const(tcx: TyCtxt<'_>, did: DefId) -> String {
 613     if let Some(did) = did.as_local() {
 614         let hir_id = tcx.hir().local_def_id_to_hir_id(did);
 615         rustc_hir_pretty::id_to_string(&tcx.hir(), hir_id)
 616     } else {
 617         tcx.rendered_const(did).clone()
 618     }
 619 }
 620
 621 fn build_const(cx: &mut DocContext<'_>, def_id: DefId) -> clean::Constant {
 622     clean::Constant {
 623         type_: clean_middle_ty(cx.tcx.type_of(def_id), cx, Some(def_id)),
 624         kind: clean::ConstantKind::Extern { def_id },
 625     }
 626 }
 627
 628 fn build_static(cx: &mut DocContext<'_>, did: DefId, mutable: bool) -> clean::Static {
 629     clean::Static {
 630         type_: clean_middle_ty(cx.tcx.type_of(did), cx, Some(did)),
 631         mutability: if mutable { Mutability::Mut } else { Mutability::Not },
 632         expr: None,
 633     }
 634 }
 635
 636 fn build_macro(
 637     cx: &mut DocContext<'_>,
 638     def_id: DefId,
 639     name: Symbol,
 640     import_def_id: Option<DefId>,
 641 ) -> clean::ItemKind {
 642     match CStore::from_tcx(cx.tcx).load_macro_untracked(def_id, cx.sess()) {
 643         LoadedMacro::MacroDef(item_def, _) => {
 644             if let ast::ItemKind::MacroDef(ref def) = item_def.kind {
 645                 let vis = clean_visibility(cx.tcx.visibility(import_def_id.unwrap_or(def_id)));
 646                 clean::MacroItem(clean::Macro {
 647                     source: utils::display_macro_source(cx, name, def, def_id, vis),
 648                 })
 649             } else {
 650                 unreachable!()
 651             }
 652         }
 653         LoadedMacro::ProcMacro(ext) => clean::ProcMacroItem(clean::ProcMacro {
 654             kind: ext.macro_kind(),
 655             helpers: ext.helper_attrs,
 656         }),
 657     }
 658 }
 659
 660 /// A trait's generics clause actually contains all of the predicates for all of
 661 /// its associated types as well. We specifically move these clauses to the
 662 /// associated types instead when displaying, so when we're generating the
 663 /// generics for the trait itself we need to be sure to remove them.
 664 /// We also need to remove the implied "recursive" Self: Trait bound.
 665 ///
 666 /// The inverse of this filtering logic can be found in the `Clean`
 667 /// implementation for `AssociatedType`
 668 fn filter_non_trait_generics(trait_did: DefId, mut g: clean::Generics) -> clean::Generics {
 669     for pred in &mut g.where_predicates {
 670         match *pred {
 671             clean::WherePredicate::BoundPredicate {
 672                 ty: clean::Generic(ref s),
 673                 ref mut bounds,
 674                 ..
 675             } if *s == kw::SelfUpper => {
 676                 bounds.retain(|bound| match bound {
 677                     clean::GenericBound::TraitBound(clean::PolyTrait { trait_, .. }, _) => {
 678                         trait_.def_id() != trait_did
 679                     }
 680                     _ => true,
 681                 });
 682             }
 683             _ => {}
 684         }
 685     }
 686
 687     g.where_predicates.retain(|pred| match pred {
 688         clean::WherePredicate::BoundPredicate {
 689             ty: clean::QPath(box clean::QPathData { self_type: clean::Generic(ref s), trait_, .. }),
 690             bounds,
 691             ..
 692         } => !(bounds.is_empty() || *s == kw::SelfUpper && trait_.def_id() == trait_did),
 693         _ => true,
 694     });
 695     g
 696 }
 697
 698 /// Supertrait bounds for a trait are also listed in the generics coming from
 699 /// the metadata for a crate, so we want to separate those out and create a new
 700 /// list of explicit supertrait bounds to render nicely.
 701 fn separate_supertrait_bounds(
 702     mut g: clean::Generics,
 703 ) -> (clean::Generics, Vec<clean::GenericBound>) {
 704     let mut ty_bounds = Vec::new();
 705     g.where_predicates.retain(|pred| match *pred {
 706         clean::WherePredicate::BoundPredicate { ty: clean::Generic(ref s), ref bounds, .. }
 707             if *s == kw::SelfUpper =>
 708         {
 709             ty_bounds.extend(bounds.iter().cloned());
 710             false
 711         }
 712         _ => true,
 713     });
 714     (g, ty_bounds)
 715 }
 716
 717 pub(crate) fn record_extern_trait(cx: &mut DocContext<'_>, did: DefId) {
 718     if did.is_local() {
 719         return;
 720     }
 721
 722     {
 723         if cx.external_traits.borrow().contains_key(&did) || cx.active_extern_traits.contains(&did)
 724         {
 725             return;
 726         }
 727     }
 728
 729     {
 730         cx.active_extern_traits.insert(did);
 731     }
 732
 733     debug!("record_extern_trait: {:?}", did);
 734     let trait_ = build_external_trait(cx, did);
 735
 736     let trait_ = clean::TraitWithExtraInfo {
 737         trait_,
 738         is_notable: clean::utils::has_doc_flag(cx.tcx, did, sym::notable_trait),
 739     };
 740     cx.external_traits.borrow_mut().insert(did, trait_);
 741     cx.active_extern_traits.remove(&did);
 742 }