1 //! The Rust AST Visitor. Extracts useful information and massages it into a form
2 //! usable for `clean`.
4 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
6 use rustc_hir::def::{DefKind, Res};
7 use rustc_hir::def_id::DefId;
9 use rustc_middle::middle::privacy::AccessLevel;
10 use rustc_middle::ty::TyCtxt;
11 use rustc_span::source_map::Spanned;
12 use rustc_span::symbol::{kw, sym, Symbol};
13 use rustc_span::{self, Span};
17 use crate::clean::{self, AttributesExt, NestedAttributesExt};
19 use crate::doctree::*;
21 // FIXME: Should this be replaced with tcx.def_path_str?
22 fn def_id_to_path(tcx: TyCtxt<'_>, did: DefId) -> Vec<String> {
23 let crate_name = tcx.crate_name(did.krate).to_string();
24 let relative = tcx.def_path(did).data.into_iter().filter_map(|elem| {
25 // extern blocks have an empty name
26 let s = elem.data.to_string();
27 if !s.is_empty() { Some(s) } else { None }
29 std::iter::once(crate_name).chain(relative).collect()
32 // Also, is there some reason that this doesn't use the 'visit'
33 // framework from syntax?.
35 crate struct RustdocVisitor<'a, 'tcx> {
36 cx: &'a mut core::DocContext<'tcx>,
37 view_item_stack: FxHashSet<hir::HirId>,
39 /// Are the current module and all of its parents public?
40 inside_public_path: bool,
41 exact_paths: FxHashMap<DefId, Vec<String>>,
44 impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
45 crate fn new(cx: &'a mut core::DocContext<'tcx>) -> RustdocVisitor<'a, 'tcx> {
46 // If the root is re-exported, terminate all recursion.
47 let mut stack = FxHashSet::default();
48 stack.insert(hir::CRATE_HIR_ID);
51 view_item_stack: stack,
53 inside_public_path: true,
54 exact_paths: FxHashMap::default(),
58 fn store_path(&mut self, did: DefId) {
59 let tcx = self.cx.tcx;
60 self.exact_paths.entry(did).or_insert_with(|| def_id_to_path(tcx, did));
63 crate fn visit(mut self, krate: &'tcx hir::Crate<'_>) -> Module<'tcx> {
64 let mut module = self.visit_mod_contents(
66 &Spanned { span: rustc_span::DUMMY_SP, node: hir::VisibilityKind::Public },
71 // Attach the crate's exported macros to the top-level module:
72 module.macros.extend(krate.exported_macros.iter().map(|def| (def, None)));
73 module.is_crate = true;
75 self.cx.renderinfo.get_mut().exact_paths = self.exact_paths;
80 fn visit_mod_contents(
83 vis: &'tcx hir::Visibility<'_>,
85 m: &'tcx hir::Mod<'tcx>,
88 let mut om = Module::new(name);
89 om.where_outer = span;
90 om.where_inner = m.inner;
92 // Keep track of if there were any private modules in the path.
93 let orig_inside_public_path = self.inside_public_path;
94 self.inside_public_path &= vis.node.is_pub();
96 let item = self.cx.tcx.hir().expect_item(i.id);
97 self.visit_item(item, None, &mut om);
99 self.inside_public_path = orig_inside_public_path;
103 /// Tries to resolve the target of a `crate use` statement and inlines the
104 /// target if it is defined locally and would not be documented otherwise,
105 /// or when it is specifically requested with `please_inline`.
106 /// (the latter is the case when the import is marked `doc(inline)`)
108 /// Cross-crate inlining occurs later on during crate cleaning
109 /// and follows different rules.
111 /// Returns `true` if the target has been inlined.
112 fn maybe_inline_local(
116 renamed: Option<Symbol>,
118 om: &mut Module<'tcx>,
121 fn inherits_doc_hidden(cx: &core::DocContext<'_>, mut node: hir::HirId) -> bool {
122 while let Some(id) = cx.tcx.hir().get_enclosing_scope(node) {
124 if cx.tcx.hir().attrs(node).lists(sym::doc).has_word(sym::hidden) {
127 if node == hir::CRATE_HIR_ID {
134 debug!("maybe_inline_local res: {:?}", res);
136 let tcx = self.cx.tcx;
137 let res_did = if let Some(did) = res.opt_def_id() {
143 let use_attrs = tcx.hir().attrs(id);
144 // Don't inline `doc(hidden)` imports so they can be stripped at a later stage.
145 let is_no_inline = use_attrs.lists(sym::doc).has_word(sym::no_inline)
146 || use_attrs.lists(sym::doc).has_word(sym::hidden);
148 // For cross-crate impl inlining we need to know whether items are
149 // reachable in documentation -- a previously nonreachable item can be
150 // made reachable by cross-crate inlining which we're checking here.
151 // (this is done here because we need to know this upfront).
152 if !res_did.is_local() && !is_no_inline {
153 let attrs = clean::inline::load_attrs(self.cx, res_did);
154 let self_is_hidden = attrs.lists(sym::doc).has_word(sym::hidden);
156 if let Res::Def(kind, did) = res {
157 if kind == DefKind::Mod {
158 crate::visit_lib::LibEmbargoVisitor::new(self.cx).visit_mod(did)
160 // All items need to be handled here in case someone wishes to link
161 // to them with intra-doc links
167 .insert(did, AccessLevel::Public);
174 let res_hir_id = match res_did.as_local() {
175 Some(n) => tcx.hir().local_def_id_to_hir_id(n),
176 None => return false,
179 let is_private = !self.cx.renderinfo.borrow().access_levels.is_public(res_did);
180 let is_hidden = inherits_doc_hidden(self.cx, res_hir_id);
182 // Only inline if requested or if the item would otherwise be stripped.
183 if (!please_inline && !is_private && !is_hidden) || is_no_inline {
187 if !self.view_item_stack.insert(res_hir_id) {
191 let ret = match tcx.hir().get(res_hir_id) {
192 Node::Item(&hir::Item { kind: hir::ItemKind::Mod(ref m), .. }) if glob => {
193 let prev = mem::replace(&mut self.inlining, true);
194 for i in m.item_ids {
195 let i = self.cx.tcx.hir().expect_item(i.id);
196 self.visit_item(i, None, om);
198 self.inlining = prev;
201 Node::Item(it) if !glob => {
202 let prev = mem::replace(&mut self.inlining, true);
203 self.visit_item(it, renamed, om);
204 self.inlining = prev;
207 Node::ForeignItem(it) if !glob => {
208 let prev = mem::replace(&mut self.inlining, true);
209 self.visit_foreign_item(it, renamed, om);
210 self.inlining = prev;
213 Node::MacroDef(def) if !glob => {
214 om.macros.push((def, renamed));
219 self.view_item_stack.remove(&res_hir_id);
225 item: &'tcx hir::Item<'_>,
226 renamed: Option<Symbol>,
227 om: &mut Module<'tcx>,
229 debug!("visiting item {:?}", item);
230 let name = renamed.unwrap_or(item.ident.name);
232 if item.vis.node.is_pub() {
233 let def_id = self.cx.tcx.hir().local_def_id(item.hir_id);
234 self.store_path(def_id.to_def_id());
238 hir::ItemKind::ForeignMod { items, .. } => {
240 let item = self.cx.tcx.hir().foreign_item(item.id);
241 self.visit_foreign_item(item, None, om);
244 // If we're inlining, skip private items.
245 _ if self.inlining && !item.vis.node.is_pub() => {}
246 hir::ItemKind::GlobalAsm(..) => {}
247 hir::ItemKind::Use(_, hir::UseKind::ListStem) => {}
248 hir::ItemKind::Use(ref path, kind) => {
249 let is_glob = kind == hir::UseKind::Glob;
251 // Struct and variant constructors and proc macro stubs always show up alongside
252 // their definitions, we've already processed them so just discard these.
253 if let Res::Def(DefKind::Ctor(..), _) | Res::SelfCtor(..) = path.res {
257 // If there was a private module in the current path then don't bother inlining
258 // anything as it will probably be stripped anyway.
259 if item.vis.node.is_pub() && self.inside_public_path {
260 let please_inline = item.attrs.iter().any(|item| match item.meta_item_list() {
261 Some(ref list) if item.has_name(sym::doc) => {
262 list.iter().any(|i| i.has_name(sym::inline))
266 let ident = if is_glob { None } else { Some(name) };
267 if self.maybe_inline_local(
279 om.imports.push(Import {
289 hir::ItemKind::Mod(ref m) => {
290 om.mods.push(self.visit_mod_contents(
298 hir::ItemKind::Fn(..)
299 | hir::ItemKind::ExternCrate(..)
300 | hir::ItemKind::Enum(..)
301 | hir::ItemKind::Struct(..)
302 | hir::ItemKind::Union(..)
303 | hir::ItemKind::TyAlias(..)
304 | hir::ItemKind::OpaqueTy(..)
305 | hir::ItemKind::Static(..)
306 | hir::ItemKind::Trait(..)
307 | hir::ItemKind::TraitAlias(..) => om.items.push((item, renamed)),
308 hir::ItemKind::Const(..) => {
309 // Underscore constants do not correspond to a nameable item and
310 // so are never useful in documentation.
311 if name != kw::Underscore {
312 om.items.push((item, renamed));
315 hir::ItemKind::Impl { ref of_trait, .. } => {
316 // Don't duplicate impls when inlining or if it's implementing a trait, we'll pick
317 // them up regardless of where they're located.
318 if !self.inlining && of_trait.is_none() {
319 om.items.push((item, None));
325 fn visit_foreign_item(
327 item: &'tcx hir::ForeignItem<'_>,
328 renamed: Option<Symbol>,
329 om: &mut Module<'tcx>,
331 // If inlining we only want to include public functions.
332 if !self.inlining || item.vis.node.is_pub() {
333 om.foreigns.push((item, renamed));