| //! Support for inlining external documentation into the current AST. |
| |
| use std::iter::once; |
| |
| use rustc::ty; |
| use rustc_ast::ast; |
| use rustc_data_structures::fx::FxHashSet; |
| use rustc_hir as hir; |
| use rustc_hir::def::{CtorKind, DefKind, Res}; |
| use rustc_hir::def_id::DefId; |
| use rustc_hir::Mutability; |
| use rustc_metadata::creader::LoadedMacro; |
| use rustc_mir::const_eval::is_min_const_fn; |
| use rustc_span::hygiene::MacroKind; |
| use rustc_span::symbol::sym; |
| use rustc_span::Span; |
| |
| use crate::clean::{self, GetDefId, ToSource, TypeKind}; |
| use crate::core::DocContext; |
| use crate::doctree; |
| |
| use super::Clean; |
| |
| type Attrs<'hir> = rustc::ty::Attributes<'hir>; |
| |
| /// Attempt to inline a definition into this AST. |
| /// |
| /// This function will fetch the definition specified, and if it is |
| /// from another crate it will attempt to inline the documentation |
| /// from the other crate into this crate. |
| /// |
| /// This is primarily used for `pub use` statements which are, in general, |
| /// implementation details. Inlining the documentation should help provide a |
| /// better experience when reading the documentation in this use case. |
| /// |
| /// The returned value is `None` if the definition could not be inlined, |
| /// and `Some` of a vector of items if it was successfully expanded. |
| pub fn try_inline( |
| cx: &DocContext<'_>, |
| res: Res, |
| name: ast::Name, |
| attrs: Option<Attrs<'_>>, |
| visited: &mut FxHashSet<DefId>, |
| ) -> Option<Vec<clean::Item>> { |
| let did = if let Some(did) = res.opt_def_id() { |
| did |
| } else { |
| return None; |
| }; |
| if did.is_local() { |
| return None; |
| } |
| let mut ret = Vec::new(); |
| |
| let attrs_clone = attrs.clone(); |
| |
| let inner = match res { |
| Res::Def(DefKind::Trait, did) => { |
| record_extern_fqn(cx, did, clean::TypeKind::Trait); |
| ret.extend(build_impls(cx, did, attrs)); |
| clean::TraitItem(build_external_trait(cx, did)) |
| } |
| Res::Def(DefKind::Fn, did) => { |
| record_extern_fqn(cx, did, clean::TypeKind::Function); |
| clean::FunctionItem(build_external_function(cx, did)) |
| } |
| Res::Def(DefKind::Struct, did) => { |
| record_extern_fqn(cx, did, clean::TypeKind::Struct); |
| ret.extend(build_impls(cx, did, attrs)); |
| clean::StructItem(build_struct(cx, did)) |
| } |
| Res::Def(DefKind::Union, did) => { |
| record_extern_fqn(cx, did, clean::TypeKind::Union); |
| ret.extend(build_impls(cx, did, attrs)); |
| clean::UnionItem(build_union(cx, did)) |
| } |
| Res::Def(DefKind::TyAlias, did) => { |
| record_extern_fqn(cx, did, clean::TypeKind::Typedef); |
| ret.extend(build_impls(cx, did, attrs)); |
| clean::TypedefItem(build_type_alias(cx, did), false) |
| } |
| Res::Def(DefKind::Enum, did) => { |
| record_extern_fqn(cx, did, clean::TypeKind::Enum); |
| ret.extend(build_impls(cx, did, attrs)); |
| clean::EnumItem(build_enum(cx, did)) |
| } |
| Res::Def(DefKind::ForeignTy, did) => { |
| record_extern_fqn(cx, did, clean::TypeKind::Foreign); |
| ret.extend(build_impls(cx, did, attrs)); |
| clean::ForeignTypeItem |
| } |
| // Never inline enum variants but leave them shown as re-exports. |
| Res::Def(DefKind::Variant, _) => return None, |
| // Assume that enum variants and struct types are re-exported next to |
| // their constructors. |
| Res::Def(DefKind::Ctor(..), _) | Res::SelfCtor(..) => return Some(Vec::new()), |
| Res::Def(DefKind::Mod, did) => { |
| record_extern_fqn(cx, did, clean::TypeKind::Module); |
| clean::ModuleItem(build_module(cx, did, visited)) |
| } |
| Res::Def(DefKind::Static, did) => { |
| record_extern_fqn(cx, did, clean::TypeKind::Static); |
| clean::StaticItem(build_static(cx, did, cx.tcx.is_mutable_static(did))) |
| } |
| Res::Def(DefKind::Const, did) => { |
| record_extern_fqn(cx, did, clean::TypeKind::Const); |
| clean::ConstantItem(build_const(cx, did)) |
| } |
| Res::Def(DefKind::Macro(kind), did) => { |
| let mac = build_macro(cx, did, name); |
| |
| let type_kind = match kind { |
| MacroKind::Bang => TypeKind::Macro, |
| MacroKind::Attr => TypeKind::Attr, |
| MacroKind::Derive => TypeKind::Derive, |
| }; |
| record_extern_fqn(cx, did, type_kind); |
| mac |
| } |
| _ => return None, |
| }; |
| |
| let target_attrs = load_attrs(cx, did); |
| let attrs = merge_attrs(cx, target_attrs, attrs_clone); |
| |
| cx.renderinfo.borrow_mut().inlined.insert(did); |
| ret.push(clean::Item { |
| source: cx.tcx.def_span(did).clean(cx), |
| name: Some(name.clean(cx)), |
| attrs, |
| inner, |
| visibility: clean::Public, |
| stability: cx.tcx.lookup_stability(did).clean(cx), |
| deprecation: cx.tcx.lookup_deprecation(did).clean(cx), |
| def_id: did, |
| }); |
| Some(ret) |
| } |
| |
| pub fn try_inline_glob( |
| cx: &DocContext<'_>, |
| res: Res, |
| visited: &mut FxHashSet<DefId>, |
| ) -> Option<Vec<clean::Item>> { |
| if res == Res::Err { |
| return None; |
| } |
| let did = res.def_id(); |
| if did.is_local() { |
| return None; |
| } |
| |
| match res { |
| Res::Def(DefKind::Mod, did) => { |
| let m = build_module(cx, did, visited); |
| Some(m.items) |
| } |
| // glob imports on things like enums aren't inlined even for local exports, so just bail |
| _ => None, |
| } |
| } |
| |
| pub fn load_attrs<'hir>(cx: &DocContext<'hir>, did: DefId) -> Attrs<'hir> { |
| cx.tcx.get_attrs(did) |
| } |
| |
| /// Record an external fully qualified name in the external_paths cache. |
| /// |
| /// These names are used later on by HTML rendering to generate things like |
| /// source links back to the original item. |
| pub fn record_extern_fqn(cx: &DocContext<'_>, did: DefId, kind: clean::TypeKind) { |
| let crate_name = cx.tcx.crate_name(did.krate).to_string(); |
| |
| let relative = cx.tcx.def_path(did).data.into_iter().filter_map(|elem| { |
| // extern blocks have an empty name |
| let s = elem.data.to_string(); |
| if !s.is_empty() { Some(s) } else { None } |
| }); |
| let fqn = if let clean::TypeKind::Macro = kind { |
| vec![crate_name, relative.last().expect("relative was empty")] |
| } else { |
| once(crate_name).chain(relative).collect() |
| }; |
| |
| if did.is_local() { |
| cx.renderinfo.borrow_mut().exact_paths.insert(did, fqn); |
| } else { |
| cx.renderinfo.borrow_mut().external_paths.insert(did, (fqn, kind)); |
| } |
| } |
| |
| pub fn build_external_trait(cx: &DocContext<'_>, did: DefId) -> clean::Trait { |
| let trait_items = |
| cx.tcx.associated_items(did).in_definition_order().map(|item| item.clean(cx)).collect(); |
| |
| let auto_trait = cx.tcx.trait_def(did).has_auto_impl; |
| let predicates = cx.tcx.predicates_of(did); |
| let generics = (cx.tcx.generics_of(did), predicates).clean(cx); |
| let generics = filter_non_trait_generics(did, generics); |
| let (generics, supertrait_bounds) = separate_supertrait_bounds(generics); |
| let is_auto = cx.tcx.trait_is_auto(did); |
| clean::Trait { |
| auto: auto_trait, |
| unsafety: cx.tcx.trait_def(did).unsafety, |
| generics, |
| items: trait_items, |
| bounds: supertrait_bounds, |
| is_auto, |
| } |
| } |
| |
| fn build_external_function(cx: &DocContext<'_>, did: DefId) -> clean::Function { |
| let sig = cx.tcx.fn_sig(did); |
| |
| let constness = |
| if is_min_const_fn(cx.tcx, did) { hir::Constness::Const } else { hir::Constness::NotConst }; |
| let asyncness = cx.tcx.asyncness(did); |
| let predicates = cx.tcx.predicates_of(did); |
| let (generics, decl) = clean::enter_impl_trait(cx, || { |
| ((cx.tcx.generics_of(did), predicates).clean(cx), (did, sig).clean(cx)) |
| }); |
| let (all_types, ret_types) = clean::get_all_types(&generics, &decl, cx); |
| clean::Function { |
| decl, |
| generics, |
| header: hir::FnHeader { unsafety: sig.unsafety(), abi: sig.abi(), constness, asyncness }, |
| all_types, |
| ret_types, |
| } |
| } |
| |
| fn build_enum(cx: &DocContext<'_>, did: DefId) -> clean::Enum { |
| let predicates = cx.tcx.explicit_predicates_of(did); |
| |
| clean::Enum { |
| generics: (cx.tcx.generics_of(did), predicates).clean(cx), |
| variants_stripped: false, |
| variants: cx.tcx.adt_def(did).variants.clean(cx), |
| } |
| } |
| |
| fn build_struct(cx: &DocContext<'_>, did: DefId) -> clean::Struct { |
| let predicates = cx.tcx.explicit_predicates_of(did); |
| let variant = cx.tcx.adt_def(did).non_enum_variant(); |
| |
| clean::Struct { |
| struct_type: match variant.ctor_kind { |
| CtorKind::Fictive => doctree::Plain, |
| CtorKind::Fn => doctree::Tuple, |
| CtorKind::Const => doctree::Unit, |
| }, |
| generics: (cx.tcx.generics_of(did), predicates).clean(cx), |
| fields: variant.fields.clean(cx), |
| fields_stripped: false, |
| } |
| } |
| |
| fn build_union(cx: &DocContext<'_>, did: DefId) -> clean::Union { |
| let predicates = cx.tcx.explicit_predicates_of(did); |
| let variant = cx.tcx.adt_def(did).non_enum_variant(); |
| |
| clean::Union { |
| struct_type: doctree::Plain, |
| generics: (cx.tcx.generics_of(did), predicates).clean(cx), |
| fields: variant.fields.clean(cx), |
| fields_stripped: false, |
| } |
| } |
| |
| fn build_type_alias(cx: &DocContext<'_>, did: DefId) -> clean::Typedef { |
| let predicates = cx.tcx.explicit_predicates_of(did); |
| |
| clean::Typedef { |
| type_: cx.tcx.type_of(did).clean(cx), |
| generics: (cx.tcx.generics_of(did), predicates).clean(cx), |
| item_type: build_type_alias_type(cx, did), |
| } |
| } |
| |
| fn build_type_alias_type(cx: &DocContext<'_>, did: DefId) -> Option<clean::Type> { |
| let type_ = cx.tcx.type_of(did).clean(cx); |
| type_.def_id().and_then(|did| build_ty(cx, did)) |
| } |
| |
| pub fn build_ty(cx: &DocContext, did: DefId) -> Option<clean::Type> { |
| match cx.tcx.def_kind(did)? { |
| DefKind::Struct | DefKind::Union | DefKind::Enum | DefKind::Const | DefKind::Static => { |
| Some(cx.tcx.type_of(did).clean(cx)) |
| } |
| DefKind::TyAlias => build_type_alias_type(cx, did), |
| _ => None, |
| } |
| } |
| |
| pub fn build_impls(cx: &DocContext<'_>, did: DefId, attrs: Option<Attrs<'_>>) -> Vec<clean::Item> { |
| let tcx = cx.tcx; |
| let mut impls = Vec::new(); |
| |
| for &did in tcx.inherent_impls(did).iter() { |
| build_impl(cx, did, attrs.clone(), &mut impls); |
| } |
| |
| impls |
| } |
| |
| fn merge_attrs( |
| cx: &DocContext<'_>, |
| attrs: Attrs<'_>, |
| other_attrs: Option<Attrs<'_>>, |
| ) -> clean::Attributes { |
| let mut merged_attrs: Vec<ast::Attribute> = Vec::with_capacity(attrs.len()); |
| // If we have additional attributes (from a re-export), |
| // always insert them first. This ensure that re-export |
| // doc comments show up before the original doc comments |
| // when we render them. |
| if let Some(a) = other_attrs { |
| merged_attrs.extend(a.iter().cloned()); |
| } |
| merged_attrs.extend(attrs.to_vec()); |
| merged_attrs.clean(cx) |
| } |
| |
| pub fn build_impl( |
| cx: &DocContext<'_>, |
| did: DefId, |
| attrs: Option<Attrs<'_>>, |
| ret: &mut Vec<clean::Item>, |
| ) { |
| if !cx.renderinfo.borrow_mut().inlined.insert(did) { |
| return; |
| } |
| |
| let attrs = merge_attrs(cx, load_attrs(cx, did), attrs); |
| |
| let tcx = cx.tcx; |
| let associated_trait = tcx.impl_trait_ref(did); |
| |
| // Only inline impl if the implemented trait is |
| // reachable in rustdoc generated documentation |
| if !did.is_local() { |
| if let Some(traitref) = associated_trait { |
| if !cx.renderinfo.borrow().access_levels.is_public(traitref.def_id) { |
| return; |
| } |
| } |
| } |
| |
| let for_ = if let Some(hir_id) = tcx.hir().as_local_hir_id(did) { |
| match tcx.hir().expect_item(hir_id).kind { |
| hir::ItemKind::Impl { self_ty, .. } => self_ty.clean(cx), |
| _ => panic!("did given to build_impl was not an impl"), |
| } |
| } else { |
| tcx.type_of(did).clean(cx) |
| }; |
| |
| // Only inline impl if the implementing type is |
| // reachable in rustdoc generated documentation |
| if !did.is_local() { |
| if let Some(did) = for_.def_id() { |
| if !cx.renderinfo.borrow().access_levels.is_public(did) { |
| return; |
| } |
| } |
| } |
| |
| let predicates = tcx.explicit_predicates_of(did); |
| let (trait_items, generics) = if let Some(hir_id) = tcx.hir().as_local_hir_id(did) { |
| match tcx.hir().expect_item(hir_id).kind { |
| hir::ItemKind::Impl { ref generics, ref items, .. } => ( |
| items.iter().map(|item| tcx.hir().impl_item(item.id).clean(cx)).collect::<Vec<_>>(), |
| generics.clean(cx), |
| ), |
| _ => panic!("did given to build_impl was not an impl"), |
| } |
| } else { |
| ( |
| tcx.associated_items(did) |
| .in_definition_order() |
| .filter_map(|item| { |
| if associated_trait.is_some() || item.vis == ty::Visibility::Public { |
| Some(item.clean(cx)) |
| } else { |
| None |
| } |
| }) |
| .collect::<Vec<_>>(), |
| clean::enter_impl_trait(cx, || (tcx.generics_of(did), predicates).clean(cx)), |
| ) |
| }; |
| let polarity = tcx.impl_polarity(did); |
| let trait_ = associated_trait.clean(cx).map(|bound| match bound { |
| clean::GenericBound::TraitBound(polyt, _) => polyt.trait_, |
| clean::GenericBound::Outlives(..) => unreachable!(), |
| }); |
| if trait_.def_id() == tcx.lang_items().deref_trait() { |
| super::build_deref_target_impls(cx, &trait_items, ret); |
| } |
| if let Some(trait_did) = trait_.def_id() { |
| record_extern_trait(cx, trait_did); |
| } |
| |
| let provided = trait_ |
| .def_id() |
| .map(|did| tcx.provided_trait_methods(did).map(|meth| meth.ident.to_string()).collect()) |
| .unwrap_or_default(); |
| |
| debug!("build_impl: impl {:?} for {:?}", trait_.def_id(), for_.def_id()); |
| |
| ret.push(clean::Item { |
| inner: clean::ImplItem(clean::Impl { |
| unsafety: hir::Unsafety::Normal, |
| generics, |
| provided_trait_methods: provided, |
| trait_, |
| for_, |
| items: trait_items, |
| polarity: Some(polarity.clean(cx)), |
| synthetic: false, |
| blanket_impl: None, |
| }), |
| source: tcx.def_span(did).clean(cx), |
| name: None, |
| attrs, |
| visibility: clean::Inherited, |
| stability: tcx.lookup_stability(did).clean(cx), |
| deprecation: tcx.lookup_deprecation(did).clean(cx), |
| def_id: did, |
| }); |
| } |
| |
| fn build_module(cx: &DocContext<'_>, did: DefId, visited: &mut FxHashSet<DefId>) -> clean::Module { |
| let mut items = Vec::new(); |
| fill_in(cx, did, &mut items, visited); |
| return clean::Module { items, is_crate: false }; |
| |
| fn fill_in( |
| cx: &DocContext<'_>, |
| did: DefId, |
| items: &mut Vec<clean::Item>, |
| visited: &mut FxHashSet<DefId>, |
| ) { |
| // If we're re-exporting a re-export it may actually re-export something in |
| // two namespaces, so the target may be listed twice. Make sure we only |
| // visit each node at most once. |
| for &item in cx.tcx.item_children(did).iter() { |
| if item.vis == ty::Visibility::Public { |
| if let Some(def_id) = item.res.mod_def_id() { |
| if did == def_id || !visited.insert(def_id) { |
| continue; |
| } |
| } |
| if let Res::PrimTy(p) = item.res { |
| // Primitive types can't be inlined so generate an import instead. |
| items.push(clean::Item { |
| name: None, |
| attrs: clean::Attributes::default(), |
| source: clean::Span::empty(), |
| def_id: cx.tcx.hir().local_def_id_from_node_id(ast::CRATE_NODE_ID), |
| visibility: clean::Public, |
| stability: None, |
| deprecation: None, |
| inner: clean::ImportItem(clean::Import::Simple( |
| item.ident.to_string(), |
| clean::ImportSource { |
| path: clean::Path { |
| global: false, |
| res: item.res, |
| segments: vec![clean::PathSegment { |
| name: clean::PrimitiveType::from(p).as_str().to_string(), |
| args: clean::GenericArgs::AngleBracketed { |
| args: Vec::new(), |
| bindings: Vec::new(), |
| }, |
| }], |
| }, |
| did: None, |
| }, |
| )), |
| }); |
| } else if let Some(i) = try_inline(cx, item.res, item.ident.name, None, visited) { |
| items.extend(i) |
| } |
| } |
| } |
| } |
| } |
| |
| pub fn print_inlined_const(cx: &DocContext<'_>, did: DefId) -> String { |
| if let Some(node_id) = cx.tcx.hir().as_local_hir_id(did) { |
| cx.tcx.hir().hir_to_pretty_string(node_id) |
| } else { |
| cx.tcx.rendered_const(did) |
| } |
| } |
| |
| fn build_const(cx: &DocContext<'_>, did: DefId) -> clean::Constant { |
| clean::Constant { |
| type_: cx.tcx.type_of(did).clean(cx), |
| expr: print_inlined_const(cx, did), |
| value: clean::utils::print_evaluated_const(cx, did), |
| is_literal: cx |
| .tcx |
| .hir() |
| .as_local_hir_id(did) |
| .map_or(false, |hir_id| clean::utils::is_literal_expr(cx, hir_id)), |
| } |
| } |
| |
| fn build_static(cx: &DocContext<'_>, did: DefId, mutable: bool) -> clean::Static { |
| clean::Static { |
| type_: cx.tcx.type_of(did).clean(cx), |
| mutability: if mutable { Mutability::Mut } else { Mutability::Not }, |
| expr: "\n\n\n".to_string(), // trigger the "[definition]" links |
| } |
| } |
| |
| fn build_macro(cx: &DocContext<'_>, did: DefId, name: ast::Name) -> clean::ItemEnum { |
| let imported_from = cx.tcx.original_crate_name(did.krate); |
| match cx.enter_resolver(|r| r.cstore().load_macro_untracked(did, cx.sess())) { |
| LoadedMacro::MacroDef(def, _) => { |
| let matchers: Vec<Span> = if let ast::ItemKind::MacroDef(ref def) = def.kind { |
| let tts: Vec<_> = def.body.inner_tokens().into_trees().collect(); |
| tts.chunks(4).map(|arm| arm[0].span()).collect() |
| } else { |
| unreachable!() |
| }; |
| |
| let source = format!( |
| "macro_rules! {} {{\n{}}}", |
| name.clean(cx), |
| matchers |
| .iter() |
| .map(|span| { format!(" {} => {{ ... }};\n", span.to_src(cx)) }) |
| .collect::<String>() |
| ); |
| |
| clean::MacroItem(clean::Macro { source, imported_from: Some(imported_from).clean(cx) }) |
| } |
| LoadedMacro::ProcMacro(ext) => clean::ProcMacroItem(clean::ProcMacro { |
| kind: ext.macro_kind(), |
| helpers: ext.helper_attrs.clean(cx), |
| }), |
| } |
| } |
| |
| /// A trait's generics clause actually contains all of the predicates for all of |
| /// its associated types as well. We specifically move these clauses to the |
| /// associated types instead when displaying, so when we're generating the |
| /// generics for the trait itself we need to be sure to remove them. |
| /// We also need to remove the implied "recursive" Self: Trait bound. |
| /// |
| /// The inverse of this filtering logic can be found in the `Clean` |
| /// implementation for `AssociatedType` |
| fn filter_non_trait_generics(trait_did: DefId, mut g: clean::Generics) -> clean::Generics { |
| for pred in &mut g.where_predicates { |
| match *pred { |
| clean::WherePredicate::BoundPredicate { ty: clean::Generic(ref s), ref mut bounds } |
| if *s == "Self" => |
| { |
| bounds.retain(|bound| match *bound { |
| clean::GenericBound::TraitBound( |
| clean::PolyTrait { trait_: clean::ResolvedPath { did, .. }, .. }, |
| _, |
| ) => did != trait_did, |
| _ => true, |
| }); |
| } |
| _ => {} |
| } |
| } |
| |
| g.where_predicates.retain(|pred| match *pred { |
| clean::WherePredicate::BoundPredicate { |
| ty: |
| clean::QPath { |
| self_type: box clean::Generic(ref s), |
| trait_: box clean::ResolvedPath { did, .. }, |
| name: ref _name, |
| }, |
| ref bounds, |
| } => !(*s == "Self" && did == trait_did) && !bounds.is_empty(), |
| _ => true, |
| }); |
| g |
| } |
| |
| /// Supertrait bounds for a trait are also listed in the generics coming from |
| /// the metadata for a crate, so we want to separate those out and create a new |
| /// list of explicit supertrait bounds to render nicely. |
| fn separate_supertrait_bounds( |
| mut g: clean::Generics, |
| ) -> (clean::Generics, Vec<clean::GenericBound>) { |
| let mut ty_bounds = Vec::new(); |
| g.where_predicates.retain(|pred| match *pred { |
| clean::WherePredicate::BoundPredicate { ty: clean::Generic(ref s), ref bounds } |
| if *s == "Self" => |
| { |
| ty_bounds.extend(bounds.iter().cloned()); |
| false |
| } |
| _ => true, |
| }); |
| (g, ty_bounds) |
| } |
| |
| pub fn record_extern_trait(cx: &DocContext<'_>, did: DefId) { |
| if did.is_local() { |
| return; |
| } |
| |
| { |
| if cx.external_traits.borrow().contains_key(&did) |
| || cx.active_extern_traits.borrow().contains(&did) |
| { |
| return; |
| } |
| } |
| |
| cx.active_extern_traits.borrow_mut().insert(did); |
| |
| debug!("record_extern_trait: {:?}", did); |
| let trait_ = build_external_trait(cx, did); |
| |
| cx.external_traits.borrow_mut().insert(did, trait_); |
| cx.active_extern_traits.borrow_mut().remove(&did); |
| } |