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;
12 use rustc_span::def_id::{CRATE_DEF_ID, LOCAL_CRATE};
13 use rustc_span::source_map::Spanned;
14 use rustc_span::symbol::{kw, sym, Symbol};
18 use crate::clean::{self, AttributesExt, NestedAttributesExt};
20 use crate::doctree::*;
22 // FIXME: Should this be replaced with tcx.def_path_str?
23 fn def_id_to_path(tcx: TyCtxt<'_>, did: DefId) -> Vec<String> {
24 let crate_name = tcx.crate_name(did.krate).to_string();
25 let relative = tcx.def_path(did).data.into_iter().filter_map(|elem| {
26 // extern blocks have an empty name
27 let s = elem.data.to_string();
28 if !s.is_empty() { Some(s) } else { None }
30 std::iter::once(crate_name).chain(relative).collect()
33 crate fn inherits_doc_hidden(tcx: TyCtxt<'_>, mut node: hir::HirId) -> bool {
34 while let Some(id) = tcx.hir().get_enclosing_scope(node) {
36 if tcx.hir().attrs(node).lists(sym::doc).has_word(sym::hidden) {
43 // Also, is there some reason that this doesn't use the 'visit'
44 // framework from syntax?.
46 crate struct RustdocVisitor<'a, 'tcx> {
47 cx: &'a mut core::DocContext<'tcx>,
48 view_item_stack: FxHashSet<hir::HirId>,
50 /// Are the current module and all of its parents public?
51 inside_public_path: bool,
52 exact_paths: FxHashMap<DefId, Vec<String>>,
55 impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
56 crate fn new(cx: &'a mut core::DocContext<'tcx>) -> RustdocVisitor<'a, 'tcx> {
57 // If the root is re-exported, terminate all recursion.
58 let mut stack = FxHashSet::default();
59 stack.insert(hir::CRATE_HIR_ID);
62 view_item_stack: stack,
64 inside_public_path: true,
65 exact_paths: FxHashMap::default(),
69 fn store_path(&mut self, did: DefId) {
70 let tcx = self.cx.tcx;
71 self.exact_paths.entry(did).or_insert_with(|| def_id_to_path(tcx, did));
74 crate fn visit(mut self, krate: &'tcx hir::Crate<'_>) -> Module<'tcx> {
75 let span = krate.module().inner;
76 let mut top_level_module = self.visit_mod_contents(
77 &Spanned { span, node: hir::VisibilityKind::Public },
80 self.cx.tcx.crate_name(LOCAL_CRATE),
83 // `#[macro_export] macro_rules!` items are reexported at the top level of the
84 // crate, regardless of where they're defined. We want to document the
85 // top level rexport of the macro, not its original definition, since
86 // the rexport defines the path that a user will actually see. Accordingly,
87 // we add the rexport as an item here, and then skip over the original
88 // definition in `visit_item()` below.
89 for export in self.cx.tcx.module_exports(CRATE_DEF_ID).unwrap_or(&[]) {
90 if let Res::Def(DefKind::Macro(_), def_id) = export.res {
91 if let Some(local_def_id) = def_id.as_local() {
92 if self.cx.tcx.has_attr(def_id, sym::macro_export) {
93 let hir_id = self.cx.tcx.hir().local_def_id_to_hir_id(local_def_id);
94 let item = self.cx.tcx.hir().expect_item(hir_id);
95 top_level_module.items.push((item, None));
100 self.cx.cache.exact_paths = self.exact_paths;
104 fn visit_mod_contents(
106 vis: &hir::Visibility<'_>,
108 m: &'tcx hir::Mod<'tcx>,
111 let mut om = Module::new(name, id, m.inner);
112 // Keep track of if there were any private modules in the path.
113 let orig_inside_public_path = self.inside_public_path;
114 self.inside_public_path &= vis.node.is_pub();
115 for &i in m.item_ids {
116 let item = self.cx.tcx.hir().item(i);
117 self.visit_item(item, None, &mut om);
119 self.inside_public_path = orig_inside_public_path;
123 /// Tries to resolve the target of a `pub use` statement and inlines the
124 /// target if it is defined locally and would not be documented otherwise,
125 /// or when it is specifically requested with `please_inline`.
126 /// (the latter is the case when the import is marked `doc(inline)`)
128 /// Cross-crate inlining occurs later on during crate cleaning
129 /// and follows different rules.
131 /// Returns `true` if the target has been inlined.
132 fn maybe_inline_local(
136 renamed: Option<Symbol>,
138 om: &mut Module<'tcx>,
141 debug!("maybe_inline_local res: {:?}", res);
143 let tcx = self.cx.tcx;
144 let res_did = if let Some(did) = res.opt_def_id() {
150 let use_attrs = tcx.hir().attrs(id);
151 // Don't inline `doc(hidden)` imports so they can be stripped at a later stage.
152 let is_no_inline = use_attrs.lists(sym::doc).has_word(sym::no_inline)
153 || use_attrs.lists(sym::doc).has_word(sym::hidden);
155 // For cross-crate impl inlining we need to know whether items are
156 // reachable in documentation -- a previously unreachable item can be
157 // made reachable by cross-crate inlining which we're checking here.
158 // (this is done here because we need to know this upfront).
159 if !res_did.is_local() && !is_no_inline {
160 let attrs = clean::inline::load_attrs(self.cx, res_did);
161 let self_is_hidden = attrs.lists(sym::doc).has_word(sym::hidden);
163 if let Res::Def(kind, did) = res {
164 if kind == DefKind::Mod {
165 crate::visit_lib::LibEmbargoVisitor::new(self.cx).visit_mod(did)
167 // All items need to be handled here in case someone wishes to link
168 // to them with intra-doc links
169 self.cx.cache.access_levels.map.insert(did, AccessLevel::Public);
176 let res_hir_id = match res_did.as_local() {
177 Some(n) => tcx.hir().local_def_id_to_hir_id(n),
178 None => return false,
181 let is_private = !self.cx.cache.access_levels.is_public(res_did);
182 let is_hidden = inherits_doc_hidden(self.cx.tcx, res_hir_id);
184 // Only inline if requested or if the item would otherwise be stripped.
185 if (!please_inline && !is_private && !is_hidden) || is_no_inline {
189 if !self.view_item_stack.insert(res_hir_id) {
193 let ret = match tcx.hir().get(res_hir_id) {
194 Node::Item(&hir::Item { kind: hir::ItemKind::Mod(ref m), .. }) if glob => {
195 let prev = mem::replace(&mut self.inlining, true);
196 for &i in m.item_ids {
197 let i = self.cx.tcx.hir().item(i);
198 self.visit_item(i, None, om);
200 self.inlining = prev;
203 Node::Item(it) if !glob => {
204 let prev = mem::replace(&mut self.inlining, true);
205 self.visit_item(it, renamed, om);
206 self.inlining = prev;
209 Node::ForeignItem(it) if !glob => {
210 let prev = mem::replace(&mut self.inlining, true);
211 self.visit_foreign_item(it, renamed, om);
212 self.inlining = prev;
217 self.view_item_stack.remove(&res_hir_id);
223 item: &'tcx hir::Item<'_>,
224 renamed: Option<Symbol>,
225 om: &mut Module<'tcx>,
227 debug!("visiting item {:?}", item);
228 let name = renamed.unwrap_or(item.ident.name);
230 let def_id = item.def_id.to_def_id();
231 let is_pub = item.vis.node.is_pub() || self.cx.tcx.has_attr(def_id, sym::macro_export);
234 self.store_path(item.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 && !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 let attrs = self.cx.tcx.hir().attrs(item.hir_id());
259 // If there was a private module in the current path then don't bother inlining
260 // anything as it will probably be stripped anyway.
261 if is_pub && self.inside_public_path {
262 let please_inline = attrs.iter().any(|item| match item.meta_item_list() {
263 Some(ref list) if item.has_name(sym::doc) => {
264 list.iter().any(|i| i.has_name(sym::inline))
268 let ident = if is_glob { None } else { Some(name) };
269 if self.maybe_inline_local(
281 om.items.push((item, renamed))
283 hir::ItemKind::Macro(ref macro_def) => {
284 // `#[macro_export] macro_rules!` items are handled seperately in `visit()`,
285 // above, since they need to be documented at the module top level. Accordingly,
286 // we only want to handle macros if one of three conditions holds:
288 // 1. This macro was defined by `macro`, and thus isn't covered by the case
290 // 2. This macro isn't marked with `#[macro_export]`, and thus isn't covered
291 // by the case above.
292 // 3. We're inlining, since a reexport where inlining has been requested
293 // should be inlined even if it is also documented at the top level.
295 let def_id = item.def_id.to_def_id();
296 let is_macro_2_0 = !macro_def.macro_rules;
297 let nonexported = !self.cx.tcx.has_attr(def_id, sym::macro_export);
299 if is_macro_2_0 || nonexported || self.inlining {
300 om.items.push((item, renamed));
303 hir::ItemKind::Mod(ref m) => {
304 om.mods.push(self.visit_mod_contents(&item.vis, item.hir_id(), m, name));
306 hir::ItemKind::Fn(..)
307 | hir::ItemKind::ExternCrate(..)
308 | hir::ItemKind::Enum(..)
309 | hir::ItemKind::Struct(..)
310 | hir::ItemKind::Union(..)
311 | hir::ItemKind::TyAlias(..)
312 | hir::ItemKind::OpaqueTy(..)
313 | hir::ItemKind::Static(..)
314 | hir::ItemKind::Trait(..)
315 | hir::ItemKind::TraitAlias(..) => om.items.push((item, renamed)),
316 hir::ItemKind::Const(..) => {
317 // Underscore constants do not correspond to a nameable item and
318 // so are never useful in documentation.
319 if name != kw::Underscore {
320 om.items.push((item, renamed));
323 hir::ItemKind::Impl(ref impl_) => {
324 // Don't duplicate impls when inlining or if it's implementing a trait, we'll pick
325 // them up regardless of where they're located.
326 if !self.inlining && impl_.of_trait.is_none() {
327 om.items.push((item, None));
333 fn visit_foreign_item(
335 item: &'tcx hir::ForeignItem<'_>,
336 renamed: Option<Symbol>,
337 om: &mut Module<'tcx>,
339 // If inlining we only want to include public functions.
340 if !self.inlining || item.vis.node.is_pub() {
341 om.foreigns.push((item, renamed));