1 //! Support for inlining external documentation into the current AST.
6 use syntax::ext::base::MacroKind;
7 use syntax::symbol::sym;
11 use rustc::hir::def::{Res, DefKind, CtorKind};
12 use rustc::hir::def_id::DefId;
13 use rustc_metadata::cstore::LoadedMacro;
15 use rustc::util::nodemap::FxHashSet;
17 use crate::core::DocContext;
28 type Attrs<'hir> = rustc::ty::Attributes<'hir>;
30 /// Attempt to inline a definition into this AST.
32 /// This function will fetch the definition specified, and if it is
33 /// from another crate it will attempt to inline the documentation
34 /// from the other crate into this crate.
36 /// This is primarily used for `pub use` statements which are, in general,
37 /// implementation details. Inlining the documentation should help provide a
38 /// better experience when reading the documentation in this use case.
40 /// The returned value is `None` if the definition could not be inlined,
41 /// and `Some` of a vector of items if it was successfully expanded.
46 attrs: Option<Attrs<'_>>,
47 visited: &mut FxHashSet<DefId>
48 ) -> Option<Vec<clean::Item>> {
49 let did = if let Some(did) = res.opt_def_id() {
54 if did.is_local() { return None }
55 let mut ret = Vec::new();
57 let attrs_clone = attrs.clone();
59 let inner = match res {
60 Res::Def(DefKind::Trait, did) => {
61 record_extern_fqn(cx, did, clean::TypeKind::Trait);
62 ret.extend(build_impls(cx, did, attrs));
63 clean::TraitItem(build_external_trait(cx, did))
65 Res::Def(DefKind::Fn, did) => {
66 record_extern_fqn(cx, did, clean::TypeKind::Function);
67 clean::FunctionItem(build_external_function(cx, did))
69 Res::Def(DefKind::Struct, did) => {
70 record_extern_fqn(cx, did, clean::TypeKind::Struct);
71 ret.extend(build_impls(cx, did, attrs));
72 clean::StructItem(build_struct(cx, did))
74 Res::Def(DefKind::Union, did) => {
75 record_extern_fqn(cx, did, clean::TypeKind::Union);
76 ret.extend(build_impls(cx, did, attrs));
77 clean::UnionItem(build_union(cx, did))
79 Res::Def(DefKind::TyAlias, did) => {
80 record_extern_fqn(cx, did, clean::TypeKind::Typedef);
81 ret.extend(build_impls(cx, did, attrs));
82 clean::TypedefItem(build_type_alias(cx, did), false)
84 Res::Def(DefKind::Enum, did) => {
85 record_extern_fqn(cx, did, clean::TypeKind::Enum);
86 ret.extend(build_impls(cx, did, attrs));
87 clean::EnumItem(build_enum(cx, did))
89 Res::Def(DefKind::ForeignTy, did) => {
90 record_extern_fqn(cx, did, clean::TypeKind::Foreign);
91 ret.extend(build_impls(cx, did, attrs));
92 clean::ForeignTypeItem
94 // Never inline enum variants but leave them shown as re-exports.
95 Res::Def(DefKind::Variant, _) => return None,
96 // Assume that enum variants and struct types are re-exported next to
97 // their constructors.
98 Res::Def(DefKind::Ctor(..), _) | Res::SelfCtor(..) => return Some(Vec::new()),
99 Res::Def(DefKind::Mod, did) => {
100 record_extern_fqn(cx, did, clean::TypeKind::Module);
101 clean::ModuleItem(build_module(cx, did, visited))
103 Res::Def(DefKind::Static, did) => {
104 record_extern_fqn(cx, did, clean::TypeKind::Static);
105 clean::StaticItem(build_static(cx, did, cx.tcx.is_mutable_static(did)))
107 Res::Def(DefKind::Const, did) => {
108 record_extern_fqn(cx, did, clean::TypeKind::Const);
109 clean::ConstantItem(build_const(cx, did))
111 Res::Def(DefKind::Macro(kind), did) => {
112 let mac = build_macro(cx, did, name);
114 let type_kind = match kind {
115 MacroKind::Bang => TypeKind::Macro,
116 MacroKind::Attr => TypeKind::Attr,
117 MacroKind::Derive => TypeKind::Derive
119 record_extern_fqn(cx, did, type_kind);
125 let target_attrs = load_attrs(cx, did);
126 let attrs = merge_attrs(cx, target_attrs, attrs_clone);
128 cx.renderinfo.borrow_mut().inlined.insert(did);
129 ret.push(clean::Item {
130 source: cx.tcx.def_span(did).clean(cx),
131 name: Some(name.clean(cx)),
134 visibility: clean::Public,
135 stability: cx.tcx.lookup_stability(did).clean(cx),
136 deprecation: cx.tcx.lookup_deprecation(did).clean(cx),
142 pub fn try_inline_glob(cx: &DocContext<'_>, res: Res, visited: &mut FxHashSet<DefId>)
143 -> Option<Vec<clean::Item>>
145 if res == Res::Err { return None }
146 let did = res.def_id();
147 if did.is_local() { return None }
150 Res::Def(DefKind::Mod, did) => {
151 let m = build_module(cx, did, visited);
154 // glob imports on things like enums aren't inlined even for local exports, so just bail
159 pub fn load_attrs<'hir>(cx: &DocContext<'hir>, did: DefId) -> Attrs<'hir> {
160 cx.tcx.get_attrs(did)
163 /// Record an external fully qualified name in the external_paths cache.
165 /// These names are used later on by HTML rendering to generate things like
166 /// source links back to the original item.
167 pub fn record_extern_fqn(cx: &DocContext<'_>, did: DefId, kind: clean::TypeKind) {
168 let crate_name = cx.tcx.crate_name(did.krate).to_string();
170 let relative = cx.tcx.def_path(did).data.into_iter().filter_map(|elem| {
171 // extern blocks have an empty name
172 let s = elem.data.to_string();
179 let fqn = if let clean::TypeKind::Macro = kind {
180 vec![crate_name, relative.last().expect("relative was empty")]
182 once(crate_name).chain(relative).collect()
186 cx.renderinfo.borrow_mut().exact_paths.insert(did, fqn);
188 cx.renderinfo.borrow_mut().external_paths.insert(did, (fqn, kind));
192 pub fn build_external_trait(cx: &DocContext<'_>, did: DefId) -> clean::Trait {
193 let auto_trait = cx.tcx.trait_def(did).has_auto_impl;
194 let trait_items = cx.tcx.associated_items(did).map(|item| item.clean(cx)).collect();
195 let predicates = cx.tcx.predicates_of(did);
196 let generics = (cx.tcx.generics_of(did), &predicates).clean(cx);
197 let generics = filter_non_trait_generics(did, generics);
198 let (generics, supertrait_bounds) = separate_supertrait_bounds(generics);
199 let is_spotlight = load_attrs(cx, did).clean(cx).has_doc_flag(sym::spotlight);
200 let is_auto = cx.tcx.trait_is_auto(did);
203 unsafety: cx.tcx.trait_def(did).unsafety,
206 bounds: supertrait_bounds,
212 fn build_external_function(cx: &DocContext<'_>, did: DefId) -> clean::Function {
213 let sig = cx.tcx.fn_sig(did);
215 let constness = if cx.tcx.is_min_const_fn(did) {
216 hir::Constness::Const
218 hir::Constness::NotConst
220 let asyncness = cx.tcx.asyncness(did);
221 let predicates = cx.tcx.predicates_of(did);
222 let (generics, decl) = clean::enter_impl_trait(cx, || {
223 ((cx.tcx.generics_of(did), &predicates).clean(cx), (did, sig).clean(cx))
225 let (all_types, ret_types) = clean::get_all_types(&generics, &decl, cx);
229 header: hir::FnHeader {
230 unsafety: sig.unsafety(),
240 fn build_enum(cx: &DocContext<'_>, did: DefId) -> clean::Enum {
241 let predicates = cx.tcx.explicit_predicates_of(did);
244 generics: (cx.tcx.generics_of(did), &predicates).clean(cx),
245 variants_stripped: false,
246 variants: cx.tcx.adt_def(did).variants.clean(cx),
250 fn build_struct(cx: &DocContext<'_>, did: DefId) -> clean::Struct {
251 let predicates = cx.tcx.explicit_predicates_of(did);
252 let variant = cx.tcx.adt_def(did).non_enum_variant();
255 struct_type: match variant.ctor_kind {
256 CtorKind::Fictive => doctree::Plain,
257 CtorKind::Fn => doctree::Tuple,
258 CtorKind::Const => doctree::Unit,
260 generics: (cx.tcx.generics_of(did), &predicates).clean(cx),
261 fields: variant.fields.clean(cx),
262 fields_stripped: false,
266 fn build_union(cx: &DocContext<'_>, did: DefId) -> clean::Union {
267 let predicates = cx.tcx.explicit_predicates_of(did);
268 let variant = cx.tcx.adt_def(did).non_enum_variant();
271 struct_type: doctree::Plain,
272 generics: (cx.tcx.generics_of(did), &predicates).clean(cx),
273 fields: variant.fields.clean(cx),
274 fields_stripped: false,
278 fn build_type_alias(cx: &DocContext<'_>, did: DefId) -> clean::Typedef {
279 let predicates = cx.tcx.explicit_predicates_of(did);
282 type_: cx.tcx.type_of(did).clean(cx),
283 generics: (cx.tcx.generics_of(did), &predicates).clean(cx),
287 pub fn build_impls(cx: &DocContext<'_>, did: DefId, attrs: Option<Attrs<'_>>) -> Vec<clean::Item> {
289 let mut impls = Vec::new();
291 for &did in tcx.inherent_impls(did).iter() {
292 build_impl(cx, did, attrs.clone(), &mut impls);
298 fn merge_attrs(cx: &DocContext<'_>, attrs: Attrs<'_>, other_attrs: Option<Attrs<'_>>
299 ) -> clean::Attributes {
300 let mut merged_attrs: Vec<ast::Attribute> = Vec::with_capacity(attrs.len());
301 // If we have additional attributes (from a re-export),
302 // always insert them first. This ensure that re-export
303 // doc comments show up before the original doc comments
304 // when we render them.
305 if let Some(a) = other_attrs {
306 merged_attrs.extend(a.iter().cloned());
308 merged_attrs.extend(attrs.to_vec());
309 merged_attrs.clean(cx)
312 pub fn build_impl(cx: &DocContext<'_>, did: DefId, attrs: Option<Attrs<'_>>,
313 ret: &mut Vec<clean::Item>
315 if !cx.renderinfo.borrow_mut().inlined.insert(did) {
319 let attrs = merge_attrs(cx, load_attrs(cx, did), attrs);
323 let associated_trait = tcx.impl_trait_ref(did);
325 // Only inline impl if the implemented trait is
326 // reachable in rustdoc generated documentation
328 if let Some(traitref) = associated_trait {
329 if !cx.renderinfo.borrow().access_levels.is_public(traitref.def_id) {
335 let for_ = if let Some(hir_id) = tcx.hir().as_local_hir_id(did) {
336 match tcx.hir().expect_item(hir_id).node {
337 hir::ItemKind::Impl(.., ref t, _) => {
340 _ => panic!("did given to build_impl was not an impl"),
343 tcx.type_of(did).clean(cx)
346 // Only inline impl if the implementing type is
347 // reachable in rustdoc generated documentation
349 if let Some(did) = for_.def_id() {
350 if !cx.renderinfo.borrow().access_levels.is_public(did) {
356 let predicates = tcx.explicit_predicates_of(did);
357 let (trait_items, generics) = if let Some(hir_id) = tcx.hir().as_local_hir_id(did) {
358 match tcx.hir().expect_item(hir_id).node {
359 hir::ItemKind::Impl(.., ref gen, _, _, ref item_ids) => {
362 .map(|ii| tcx.hir().impl_item(ii.id).clean(cx))
363 .collect::<Vec<_>>(),
367 _ => panic!("did given to build_impl was not an impl"),
371 tcx.associated_items(did).filter_map(|item| {
372 if associated_trait.is_some() || item.vis == ty::Visibility::Public {
377 }).collect::<Vec<_>>(),
378 clean::enter_impl_trait(cx, || {
379 (tcx.generics_of(did), &predicates).clean(cx)
383 let polarity = tcx.impl_polarity(did);
384 let trait_ = associated_trait.clean(cx).map(|bound| {
386 clean::GenericBound::TraitBound(polyt, _) => polyt.trait_,
387 clean::GenericBound::Outlives(..) => unreachable!(),
390 if trait_.def_id() == tcx.lang_items().deref_trait() {
391 super::build_deref_target_impls(cx, &trait_items, ret);
393 if let Some(trait_did) = trait_.def_id() {
394 record_extern_trait(cx, trait_did);
397 let provided = trait_.def_id().map(|did| {
398 tcx.provided_trait_methods(did)
400 .map(|meth| meth.ident.to_string())
402 }).unwrap_or_default();
404 debug!("build_impl: impl {:?} for {:?}", trait_.def_id(), for_.def_id());
406 ret.push(clean::Item {
407 inner: clean::ImplItem(clean::Impl {
408 unsafety: hir::Unsafety::Normal,
410 provided_trait_methods: provided,
414 polarity: Some(polarity.clean(cx)),
418 source: tcx.def_span(did).clean(cx),
421 visibility: clean::Inherited,
422 stability: tcx.lookup_stability(did).clean(cx),
423 deprecation: tcx.lookup_deprecation(did).clean(cx),
431 visited: &mut FxHashSet<DefId>
433 let mut items = Vec::new();
434 fill_in(cx, did, &mut items, visited);
435 return clean::Module {
440 fn fill_in(cx: &DocContext<'_>, did: DefId, items: &mut Vec<clean::Item>,
441 visited: &mut FxHashSet<DefId>) {
442 // If we're re-exporting a re-export it may actually re-export something in
443 // two namespaces, so the target may be listed twice. Make sure we only
444 // visit each node at most once.
445 for &item in cx.tcx.item_children(did).iter() {
446 let def_id = item.res.def_id();
447 if item.vis == ty::Visibility::Public {
448 if did == def_id || !visited.insert(def_id) { continue }
449 if let Some(i) = try_inline(cx, item.res, item.ident.name, None, visited) {
457 pub fn print_inlined_const(cx: &DocContext<'_>, did: DefId) -> String {
458 if let Some(node_id) = cx.tcx.hir().as_local_hir_id(did) {
459 cx.tcx.hir().hir_to_pretty_string(node_id)
461 cx.tcx.rendered_const(did)
465 fn build_const(cx: &DocContext<'_>, did: DefId) -> clean::Constant {
467 type_: cx.tcx.type_of(did).clean(cx),
468 expr: print_inlined_const(cx, did)
472 fn build_static(cx: &DocContext<'_>, did: DefId, mutable: bool) -> clean::Static {
474 type_: cx.tcx.type_of(did).clean(cx),
475 mutability: if mutable {clean::Mutable} else {clean::Immutable},
476 expr: "\n\n\n".to_string(), // trigger the "[definition]" links
480 fn build_macro(cx: &DocContext<'_>, did: DefId, name: ast::Name) -> clean::ItemEnum {
481 let imported_from = cx.tcx.original_crate_name(did.krate);
482 match cx.cstore.load_macro_untracked(did, cx.sess()) {
483 LoadedMacro::MacroDef(def) => {
484 let matchers: hir::HirVec<Span> = if let ast::ItemKind::MacroDef(ref def) = def.node {
485 let tts: Vec<_> = def.stream().into_trees().collect();
486 tts.chunks(4).map(|arm| arm[0].span()).collect()
491 let source = format!("macro_rules! {} {{\n{}}}",
493 matchers.iter().map(|span| {
494 format!(" {} => {{ ... }};\n", span.to_src(cx))
495 }).collect::<String>());
497 clean::MacroItem(clean::Macro {
499 imported_from: Some(imported_from).clean(cx),
502 LoadedMacro::ProcMacro(ext) => {
503 clean::ProcMacroItem(clean::ProcMacro {
504 kind: ext.macro_kind(),
505 helpers: ext.helper_attrs.clean(cx),
511 /// A trait's generics clause actually contains all of the predicates for all of
512 /// its associated types as well. We specifically move these clauses to the
513 /// associated types instead when displaying, so when we're generating the
514 /// generics for the trait itself we need to be sure to remove them.
515 /// We also need to remove the implied "recursive" Self: Trait bound.
517 /// The inverse of this filtering logic can be found in the `Clean`
518 /// implementation for `AssociatedType`
519 fn filter_non_trait_generics(trait_did: DefId, mut g: clean::Generics) -> clean::Generics {
520 for pred in &mut g.where_predicates {
522 clean::WherePredicate::BoundPredicate {
523 ty: clean::Generic(ref s),
525 } if *s == "Self" => {
526 bounds.retain(|bound| {
528 clean::GenericBound::TraitBound(clean::PolyTrait {
529 trait_: clean::ResolvedPath { did, .. },
531 }, _) => did != trait_did,
540 g.where_predicates.retain(|pred| {
542 clean::WherePredicate::BoundPredicate {
544 self_type: box clean::Generic(ref s),
545 trait_: box clean::ResolvedPath { did, .. },
548 } => !(*s == "Self" && did == trait_did) && !bounds.is_empty(),
555 /// Supertrait bounds for a trait are also listed in the generics coming from
556 /// the metadata for a crate, so we want to separate those out and create a new
557 /// list of explicit supertrait bounds to render nicely.
558 fn separate_supertrait_bounds(mut g: clean::Generics)
559 -> (clean::Generics, Vec<clean::GenericBound>) {
560 let mut ty_bounds = Vec::new();
561 g.where_predicates.retain(|pred| {
563 clean::WherePredicate::BoundPredicate {
564 ty: clean::Generic(ref s),
566 } if *s == "Self" => {
567 ty_bounds.extend(bounds.iter().cloned());
576 pub fn record_extern_trait(cx: &DocContext<'_>, did: DefId) {
582 if cx.external_traits.borrow().contains_key(&did) ||
583 cx.active_extern_traits.borrow().contains(&did)
589 cx.active_extern_traits.borrow_mut().insert(did);
591 debug!("record_extern_trait: {:?}", did);
592 let trait_ = build_external_trait(cx, did);
594 cx.external_traits.borrow_mut().insert(did, trait_);
595 cx.active_extern_traits.borrow_mut().remove(&did);