1 // Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! Support for inlining external documentation into the current AST.
13 use std::collections::BTreeMap;
21 use rustc::hir::def::{Def, CtorKind};
22 use rustc::hir::def_id::DefId;
24 use rustc::util::nodemap::FxHashSet;
26 use core::{DocContext, DocAccessLevels};
28 use clean::{self, GetDefId};
32 /// Attempt to inline a definition into this AST.
34 /// This function will fetch the definition specified, and if it is
35 /// from another crate it will attempt to inline the documentation
36 /// from the other crate into this crate.
38 /// This is primarily used for `pub use` statements which are, in general,
39 /// implementation details. Inlining the documentation should help provide a
40 /// better experience when reading the documentation in this use case.
42 /// The returned value is `None` if the definition could not be inlined,
43 /// and `Some` of a vector of items if it was successfully expanded.
44 pub fn try_inline(cx: &DocContext, def: Def, name: ast::Name)
45 -> Option<Vec<clean::Item>> {
46 if def == Def::Err { return None }
47 let did = def.def_id();
48 if did.is_local() { return None }
49 let mut ret = Vec::new();
50 let inner = match def {
52 record_extern_fqn(cx, did, clean::TypeKind::Trait);
53 ret.extend(build_impls(cx, did));
54 clean::TraitItem(build_external_trait(cx, did))
57 record_extern_fqn(cx, did, clean::TypeKind::Function);
58 clean::FunctionItem(build_external_function(cx, did))
61 record_extern_fqn(cx, did, clean::TypeKind::Struct);
62 ret.extend(build_impls(cx, did));
63 clean::StructItem(build_struct(cx, did))
66 record_extern_fqn(cx, did, clean::TypeKind::Union);
67 ret.extend(build_impls(cx, did));
68 clean::UnionItem(build_union(cx, did))
70 Def::TyAlias(did) => {
71 record_extern_fqn(cx, did, clean::TypeKind::Typedef);
72 ret.extend(build_impls(cx, did));
73 clean::TypedefItem(build_type_alias(cx, did), false)
76 record_extern_fqn(cx, did, clean::TypeKind::Enum);
77 ret.extend(build_impls(cx, did));
78 clean::EnumItem(build_enum(cx, did))
80 // Never inline enum variants but leave them shown as reexports.
81 Def::Variant(..) => return None,
82 // Assume that enum variants and struct types are reexported next to
83 // their constructors.
84 Def::VariantCtor(..) |
85 Def::StructCtor(..) => return Some(Vec::new()),
87 record_extern_fqn(cx, did, clean::TypeKind::Module);
88 clean::ModuleItem(build_module(cx, did))
90 Def::Static(did, mtbl) => {
91 record_extern_fqn(cx, did, clean::TypeKind::Static);
92 clean::StaticItem(build_static(cx, did, mtbl))
95 record_extern_fqn(cx, did, clean::TypeKind::Const);
96 clean::ConstantItem(build_const(cx, did))
100 cx.renderinfo.borrow_mut().inlined.insert(did);
101 ret.push(clean::Item {
102 source: cx.tcx.def_span(did).clean(cx),
103 name: Some(name.clean(cx)),
104 attrs: load_attrs(cx, did),
106 visibility: Some(clean::Public),
107 stability: cx.tcx.lookup_stability(did).clean(cx),
108 deprecation: cx.tcx.lookup_deprecation(did).clean(cx),
114 pub fn load_attrs(cx: &DocContext, did: DefId) -> clean::Attributes {
115 cx.tcx.get_attrs(did).clean(cx)
118 /// Record an external fully qualified name in the external_paths cache.
120 /// These names are used later on by HTML rendering to generate things like
121 /// source links back to the original item.
122 pub fn record_extern_fqn(cx: &DocContext, did: DefId, kind: clean::TypeKind) {
123 let crate_name = cx.tcx.crate_name(did.krate).to_string();
124 let relative = cx.tcx.def_path(did).data.into_iter().filter_map(|elem| {
125 // extern blocks have an empty name
126 let s = elem.data.to_string();
133 let fqn = once(crate_name).chain(relative).collect();
134 cx.renderinfo.borrow_mut().external_paths.insert(did, (fqn, kind));
137 pub fn build_external_trait(cx: &DocContext, did: DefId) -> clean::Trait {
138 let trait_items = cx.tcx.associated_items(did).map(|item| item.clean(cx)).collect();
139 let predicates = cx.tcx.predicates_of(did);
140 let generics = (cx.tcx.generics_of(did), &predicates).clean(cx);
141 let generics = filter_non_trait_generics(did, generics);
142 let (generics, supertrait_bounds) = separate_supertrait_bounds(generics);
144 unsafety: cx.tcx.trait_def(did).unsafety,
147 bounds: supertrait_bounds,
151 fn build_external_function(cx: &DocContext, did: DefId) -> clean::Function {
152 let sig = cx.tcx.fn_sig(did);
154 let constness = if cx.tcx.is_const_fn(did) {
155 hir::Constness::Const
157 hir::Constness::NotConst
160 let predicates = cx.tcx.predicates_of(did);
162 decl: (did, sig).clean(cx),
163 generics: (cx.tcx.generics_of(did), &predicates).clean(cx),
164 unsafety: sig.unsafety(),
170 fn build_enum(cx: &DocContext, did: DefId) -> clean::Enum {
171 let predicates = cx.tcx.predicates_of(did);
174 generics: (cx.tcx.generics_of(did), &predicates).clean(cx),
175 variants_stripped: false,
176 variants: cx.tcx.adt_def(did).variants.clean(cx),
180 fn build_struct(cx: &DocContext, did: DefId) -> clean::Struct {
181 let predicates = cx.tcx.predicates_of(did);
182 let variant = cx.tcx.adt_def(did).struct_variant();
185 struct_type: match variant.ctor_kind {
186 CtorKind::Fictive => doctree::Plain,
187 CtorKind::Fn => doctree::Tuple,
188 CtorKind::Const => doctree::Unit,
190 generics: (cx.tcx.generics_of(did), &predicates).clean(cx),
191 fields: variant.fields.clean(cx),
192 fields_stripped: false,
196 fn build_union(cx: &DocContext, did: DefId) -> clean::Union {
197 let predicates = cx.tcx.predicates_of(did);
198 let variant = cx.tcx.adt_def(did).struct_variant();
201 struct_type: doctree::Plain,
202 generics: (cx.tcx.generics_of(did), &predicates).clean(cx),
203 fields: variant.fields.clean(cx),
204 fields_stripped: false,
208 fn build_type_alias(cx: &DocContext, did: DefId) -> clean::Typedef {
209 let predicates = cx.tcx.predicates_of(did);
212 type_: cx.tcx.type_of(did).clean(cx),
213 generics: (cx.tcx.generics_of(did), &predicates).clean(cx),
217 pub fn build_impls(cx: &DocContext, did: DefId) -> Vec<clean::Item> {
219 let mut impls = Vec::new();
221 for &did in tcx.inherent_impls(did).iter() {
222 build_impl(cx, did, &mut impls);
225 // If this is the first time we've inlined something from another crate, then
226 // we inline *all* impls from all the crates into this crate. Note that there's
227 // currently no way for us to filter this based on type, and we likely need
228 // many impls for a variety of reasons.
230 // Primarily, the impls will be used to populate the documentation for this
231 // type being inlined, but impls can also be used when generating
232 // documentation for primitives (no way to find those specifically).
233 if cx.populated_all_crate_impls.get() {
237 cx.populated_all_crate_impls.set(true);
239 for cnum in tcx.sess.cstore.crates() {
240 for did in tcx.all_trait_implementations(cnum).iter() {
241 build_impl(cx, *did, &mut impls);
245 // Also try to inline primitive impls from other crates.
246 let lang_items = tcx.lang_items();
247 let primitive_impls = [
248 lang_items.isize_impl(),
249 lang_items.i8_impl(),
250 lang_items.i16_impl(),
251 lang_items.i32_impl(),
252 lang_items.i64_impl(),
253 lang_items.i128_impl(),
254 lang_items.usize_impl(),
255 lang_items.u8_impl(),
256 lang_items.u16_impl(),
257 lang_items.u32_impl(),
258 lang_items.u64_impl(),
259 lang_items.u128_impl(),
260 lang_items.f32_impl(),
261 lang_items.f64_impl(),
262 lang_items.char_impl(),
263 lang_items.str_impl(),
264 lang_items.slice_impl(),
265 lang_items.const_ptr_impl(),
266 lang_items.mut_ptr_impl(),
269 for def_id in primitive_impls.iter().filter_map(|&def_id| def_id) {
270 if !def_id.is_local() {
271 build_impl(cx, def_id, &mut impls);
278 pub fn build_impl(cx: &DocContext, did: DefId, ret: &mut Vec<clean::Item>) {
279 if !cx.renderinfo.borrow_mut().inlined.insert(did) {
283 let attrs = load_attrs(cx, did);
285 let associated_trait = tcx.impl_trait_ref(did);
287 // Only inline impl if the implemented trait is
288 // reachable in rustdoc generated documentation
289 if let Some(traitref) = associated_trait {
290 if !cx.access_levels.borrow().is_doc_reachable(traitref.def_id) {
295 // If this is a defaulted impl, then bail out early here
296 if tcx.is_default_impl(did) {
297 return ret.push(clean::Item {
298 inner: clean::DefaultImplItem(clean::DefaultImpl {
299 // FIXME: this should be decoded
300 unsafety: hir::Unsafety::Normal,
301 trait_: match associated_trait.as_ref().unwrap().clean(cx) {
302 clean::TraitBound(polyt, _) => polyt.trait_,
303 clean::RegionBound(..) => unreachable!(),
306 source: tcx.def_span(did).clean(cx),
309 visibility: Some(clean::Inherited),
310 stability: tcx.lookup_stability(did).clean(cx),
311 deprecation: tcx.lookup_deprecation(did).clean(cx),
316 let for_ = tcx.type_of(did).clean(cx);
318 // Only inline impl if the implementing type is
319 // reachable in rustdoc generated documentation
320 if let Some(did) = for_.def_id() {
321 if !cx.access_levels.borrow().is_doc_reachable(did) {
326 let predicates = tcx.predicates_of(did);
327 let trait_items = tcx.associated_items(did).filter_map(|item| {
329 ty::AssociatedKind::Const => {
330 let default = if item.defaultness.has_value() {
331 Some(print_inlined_const(cx, item.def_id))
336 name: Some(item.name.clean(cx)),
337 inner: clean::AssociatedConstItem(
338 tcx.type_of(item.def_id).clean(cx),
341 source: tcx.def_span(item.def_id).clean(cx),
342 attrs: clean::Attributes::default(),
344 stability: tcx.lookup_stability(item.def_id).clean(cx),
345 deprecation: tcx.lookup_deprecation(item.def_id).clean(cx),
349 ty::AssociatedKind::Method => {
350 if item.vis != ty::Visibility::Public && associated_trait.is_none() {
353 let mut cleaned = item.clean(cx);
354 cleaned.inner = match cleaned.inner.clone() {
355 clean::TyMethodItem(clean::TyMethod {
356 unsafety, decl, generics, abi
358 let constness = if tcx.is_const_fn(item.def_id) {
359 hir::Constness::Const
361 hir::Constness::NotConst
364 clean::MethodItem(clean::Method {
372 ref r => panic!("not a tymethod: {:?}", r),
376 ty::AssociatedKind::Type => {
377 let typedef = clean::Typedef {
378 type_: tcx.type_of(item.def_id).clean(cx),
379 generics: clean::Generics {
382 where_predicates: vec![]
386 name: Some(item.name.clean(cx)),
387 inner: clean::TypedefItem(typedef, true),
388 source: tcx.def_span(item.def_id).clean(cx),
389 attrs: clean::Attributes::default(),
391 stability: tcx.lookup_stability(item.def_id).clean(cx),
392 deprecation: tcx.lookup_deprecation(item.def_id).clean(cx),
397 }).collect::<Vec<_>>();
398 let polarity = tcx.impl_polarity(did);
399 let trait_ = associated_trait.clean(cx).map(|bound| {
401 clean::TraitBound(polyt, _) => polyt.trait_,
402 clean::RegionBound(..) => unreachable!(),
405 if trait_.def_id() == tcx.lang_items().deref_trait() {
406 super::build_deref_target_impls(cx, &trait_items, ret);
409 let provided = trait_.def_id().map(|did| {
410 tcx.provided_trait_methods(did)
412 .map(|meth| meth.name.to_string())
414 }).unwrap_or(FxHashSet());
416 ret.push(clean::Item {
417 inner: clean::ImplItem(clean::Impl {
418 unsafety: hir::Unsafety::Normal, // FIXME: this should be decoded
419 provided_trait_methods: provided,
422 generics: (tcx.generics_of(did), &predicates).clean(cx),
424 polarity: Some(polarity.clean(cx)),
426 source: tcx.def_span(did).clean(cx),
429 visibility: Some(clean::Inherited),
430 stability: tcx.lookup_stability(did).clean(cx),
431 deprecation: tcx.lookup_deprecation(did).clean(cx),
436 fn build_module(cx: &DocContext, did: DefId) -> clean::Module {
437 let mut items = Vec::new();
438 fill_in(cx, did, &mut items);
439 return clean::Module {
444 fn fill_in(cx: &DocContext, did: DefId, items: &mut Vec<clean::Item>) {
445 // If we're reexporting a reexport it may actually reexport something in
446 // two namespaces, so the target may be listed twice. Make sure we only
447 // visit each node at most once.
448 let mut visited = FxHashSet();
449 for &item in cx.tcx.item_children(did).iter() {
450 let def_id = item.def.def_id();
451 if cx.tcx.visibility(def_id) == ty::Visibility::Public {
452 if !visited.insert(def_id) { continue }
453 if let Some(i) = try_inline(cx, item.def, item.ident.name) {
461 struct InlinedConst {
462 nested_bodies: Rc<BTreeMap<hir::BodyId, hir::Body>>
465 impl hir::print::PpAnn for InlinedConst {
466 fn nested(&self, state: &mut hir::print::State, nested: hir::print::Nested)
468 if let hir::print::Nested::Body(body) = nested {
469 state.print_expr(&self.nested_bodies[&body].value)
476 fn print_inlined_const(cx: &DocContext, did: DefId) -> String {
477 let body = cx.tcx.extern_const_body(did);
478 let inlined = InlinedConst {
479 nested_bodies: cx.tcx.item_body_nested_bodies(did)
481 hir::print::to_string(&inlined, |s| s.print_expr(&body.value))
484 fn build_const(cx: &DocContext, did: DefId) -> clean::Constant {
486 type_: cx.tcx.type_of(did).clean(cx),
487 expr: print_inlined_const(cx, did)
491 fn build_static(cx: &DocContext, did: DefId, mutable: bool) -> clean::Static {
493 type_: cx.tcx.type_of(did).clean(cx),
494 mutability: if mutable {clean::Mutable} else {clean::Immutable},
495 expr: "\n\n\n".to_string(), // trigger the "[definition]" links
499 /// A trait's generics clause actually contains all of the predicates for all of
500 /// its associated types as well. We specifically move these clauses to the
501 /// associated types instead when displaying, so when we're generating the
502 /// generics for the trait itself we need to be sure to remove them.
503 /// We also need to remove the implied "recursive" Self: Trait bound.
505 /// The inverse of this filtering logic can be found in the `Clean`
506 /// implementation for `AssociatedType`
507 fn filter_non_trait_generics(trait_did: DefId, mut g: clean::Generics)
509 for pred in &mut g.where_predicates {
511 clean::WherePredicate::BoundPredicate {
512 ty: clean::Generic(ref s),
514 } if *s == "Self" => {
515 bounds.retain(|bound| {
517 clean::TyParamBound::TraitBound(clean::PolyTrait {
518 trait_: clean::ResolvedPath { did, .. },
520 }, _) => did != trait_did,
529 g.where_predicates.retain(|pred| {
531 clean::WherePredicate::BoundPredicate {
533 self_type: box clean::Generic(ref s),
534 trait_: box clean::ResolvedPath { did, .. },
537 } => !(*s == "Self" && did == trait_did) && !bounds.is_empty(),
544 /// Supertrait bounds for a trait are also listed in the generics coming from
545 /// the metadata for a crate, so we want to separate those out and create a new
546 /// list of explicit supertrait bounds to render nicely.
547 fn separate_supertrait_bounds(mut g: clean::Generics)
548 -> (clean::Generics, Vec<clean::TyParamBound>) {
549 let mut ty_bounds = Vec::new();
550 g.where_predicates.retain(|pred| {
552 clean::WherePredicate::BoundPredicate {
553 ty: clean::Generic(ref s),
555 } if *s == "Self" => {
556 ty_bounds.extend(bounds.iter().cloned());