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_hir::CRATE_HIR_ID;
10 use rustc_middle::ty::TyCtxt;
11 use rustc_span::def_id::{CRATE_DEF_ID, LOCAL_CRATE};
12 use rustc_span::symbol::{kw, sym, Symbol};
17 use crate::clean::{cfg::Cfg, AttributesExt, NestedAttributesExt};
20 /// This module is used to store stuff from Rust's AST in a more convenient
21 /// manner (and with prettier names) before cleaning.
23 pub(crate) struct Module<'hir> {
24 pub(crate) name: Symbol,
25 pub(crate) where_inner: Span,
26 pub(crate) mods: Vec<Module<'hir>>,
27 pub(crate) id: hir::HirId,
29 pub(crate) items: Vec<(&'hir hir::Item<'hir>, Option<Symbol>)>,
30 pub(crate) foreigns: Vec<(&'hir hir::ForeignItem<'hir>, Option<Symbol>)>,
34 pub(crate) fn new(name: Symbol, id: hir::HirId, where_inner: Span) -> Self {
35 Module { name, id, where_inner, mods: Vec::new(), items: Vec::new(), foreigns: Vec::new() }
38 pub(crate) fn where_outer(&self, tcx: TyCtxt<'_>) -> Span {
39 tcx.hir().span(self.id)
43 // FIXME: Should this be replaced with tcx.def_path_str?
44 fn def_id_to_path(tcx: TyCtxt<'_>, did: DefId) -> Vec<Symbol> {
45 let crate_name = tcx.crate_name(did.krate);
46 let relative = tcx.def_path(did).data.into_iter().filter_map(|elem| elem.data.get_opt_name());
47 std::iter::once(crate_name).chain(relative).collect()
50 pub(crate) fn inherits_doc_hidden(tcx: TyCtxt<'_>, mut node: hir::HirId) -> bool {
51 while let Some(id) = tcx.hir().get_enclosing_scope(node) {
53 if tcx.hir().attrs(node).lists(sym::doc).has_word(sym::hidden) {
60 // Also, is there some reason that this doesn't use the 'visit'
61 // framework from syntax?.
63 pub(crate) struct RustdocVisitor<'a, 'tcx> {
64 cx: &'a mut core::DocContext<'tcx>,
65 view_item_stack: FxHashSet<hir::HirId>,
67 /// Are the current module and all of its parents public?
68 inside_public_path: bool,
69 exact_paths: FxHashMap<DefId, Vec<Symbol>>,
72 impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
73 pub(crate) fn new(cx: &'a mut core::DocContext<'tcx>) -> RustdocVisitor<'a, 'tcx> {
74 // If the root is re-exported, terminate all recursion.
75 let mut stack = FxHashSet::default();
76 stack.insert(hir::CRATE_HIR_ID);
79 view_item_stack: stack,
81 inside_public_path: true,
82 exact_paths: FxHashMap::default(),
86 fn store_path(&mut self, did: DefId) {
87 let tcx = self.cx.tcx;
88 self.exact_paths.entry(did).or_insert_with(|| def_id_to_path(tcx, did));
91 pub(crate) fn visit(mut self) -> Module<'tcx> {
92 let mut top_level_module = self.visit_mod_contents(
94 self.cx.tcx.hir().root_module(),
95 self.cx.tcx.crate_name(LOCAL_CRATE),
98 // `#[macro_export] macro_rules!` items are reexported at the top level of the
99 // crate, regardless of where they're defined. We want to document the
100 // top level rexport of the macro, not its original definition, since
101 // the rexport defines the path that a user will actually see. Accordingly,
102 // we add the rexport as an item here, and then skip over the original
103 // definition in `visit_item()` below.
105 // We also skip `#[macro_export] macro_rules!` that have already been inserted,
106 // it can happen if within the same module a `#[macro_export] macro_rules!`
107 // is declared but also a reexport of itself producing two exports of the same
108 // macro in the same module.
109 let mut inserted = FxHashSet::default();
110 for export in self.cx.tcx.module_reexports(CRATE_DEF_ID).unwrap_or(&[]) {
111 if let Res::Def(DefKind::Macro(_), def_id) = export.res {
112 if let Some(local_def_id) = def_id.as_local() {
113 if self.cx.tcx.has_attr(def_id, sym::macro_export) {
114 if inserted.insert(def_id) {
115 let item = self.cx.tcx.hir().expect_item(local_def_id);
116 top_level_module.items.push((item, None));
123 self.cx.cache.hidden_cfg = self
129 .filter(|attr| attr.has_name(sym::doc))
130 .flat_map(|attr| attr.meta_item_list().into_iter().flatten())
131 .filter(|attr| attr.has_name(sym::cfg_hide))
133 attr.meta_item_list()
137 Cfg::parse(attr.meta_item()?)
138 .map_err(|e| self.cx.sess().diagnostic().span_err(e.span, e.msg))
144 [Cfg::Cfg(sym::test, None), Cfg::Cfg(sym::doc, None), Cfg::Cfg(sym::doctest, None)]
149 self.cx.cache.exact_paths = self.exact_paths;
153 fn visit_mod_contents(
156 m: &'tcx hir::Mod<'tcx>,
159 let mut om = Module::new(name, id, m.spans.inner_span);
160 let def_id = self.cx.tcx.hir().local_def_id(id).to_def_id();
161 // Keep track of if there were any private modules in the path.
162 let orig_inside_public_path = self.inside_public_path;
163 self.inside_public_path &= self.cx.tcx.visibility(def_id).is_public();
164 for &i in m.item_ids {
165 let item = self.cx.tcx.hir().item(i);
166 if matches!(item.kind, hir::ItemKind::Use(_, hir::UseKind::Glob)) {
169 self.visit_item(item, None, &mut om);
171 for &i in m.item_ids {
172 let item = self.cx.tcx.hir().item(i);
173 // To match the way import precedence works, visit glob imports last.
174 // Later passes in rustdoc will de-duplicate by name and kind, so if glob-
175 // imported items appear last, then they'll be the ones that get discarded.
176 if matches!(item.kind, hir::ItemKind::Use(_, hir::UseKind::Glob)) {
177 self.visit_item(item, None, &mut om);
180 self.inside_public_path = orig_inside_public_path;
184 /// Tries to resolve the target of a `pub use` statement and inlines the
185 /// target if it is defined locally and would not be documented otherwise,
186 /// or when it is specifically requested with `please_inline`.
187 /// (the latter is the case when the import is marked `doc(inline)`)
189 /// Cross-crate inlining occurs later on during crate cleaning
190 /// and follows different rules.
192 /// Returns `true` if the target has been inlined.
193 fn maybe_inline_local(
197 renamed: Option<Symbol>,
199 om: &mut Module<'tcx>,
202 debug!("maybe_inline_local res: {:?}", res);
204 if self.cx.output_format.is_json() {
208 let tcx = self.cx.tcx;
209 let Some(res_did) = res.opt_def_id() else {
213 let use_attrs = tcx.hir().attrs(id);
214 // Don't inline `doc(hidden)` imports so they can be stripped at a later stage.
215 let is_no_inline = use_attrs.lists(sym::doc).has_word(sym::no_inline)
216 || use_attrs.lists(sym::doc).has_word(sym::hidden);
218 // For cross-crate impl inlining we need to know whether items are
219 // reachable in documentation -- a previously unreachable item can be
220 // made reachable by cross-crate inlining which we're checking here.
221 // (this is done here because we need to know this upfront).
222 if !res_did.is_local() && !is_no_inline {
223 crate::visit_lib::lib_embargo_visit_item(self.cx, res_did);
227 let res_hir_id = match res_did.as_local() {
228 Some(n) => tcx.hir().local_def_id_to_hir_id(n),
229 None => return false,
233 !self.cx.cache.effective_visibilities.is_directly_public(self.cx.tcx, res_did);
234 let is_hidden = inherits_doc_hidden(self.cx.tcx, res_hir_id);
236 // Only inline if requested or if the item would otherwise be stripped.
237 if (!please_inline && !is_private && !is_hidden) || is_no_inline {
241 if !self.view_item_stack.insert(res_hir_id) {
245 let ret = match tcx.hir().get(res_hir_id) {
246 Node::Item(&hir::Item { kind: hir::ItemKind::Mod(ref m), .. }) if glob => {
247 let prev = mem::replace(&mut self.inlining, true);
248 for &i in m.item_ids {
249 let i = self.cx.tcx.hir().item(i);
250 self.visit_item(i, None, om);
252 self.inlining = prev;
255 Node::Item(it) if !glob => {
256 let prev = mem::replace(&mut self.inlining, true);
257 self.visit_item(it, renamed, om);
258 self.inlining = prev;
261 Node::ForeignItem(it) if !glob => {
262 let prev = mem::replace(&mut self.inlining, true);
263 self.visit_foreign_item(it, renamed, om);
264 self.inlining = prev;
269 self.view_item_stack.remove(&res_hir_id);
275 item: &'tcx hir::Item<'_>,
276 renamed: Option<Symbol>,
277 om: &mut Module<'tcx>,
279 debug!("visiting item {:?}", item);
280 let name = renamed.unwrap_or(item.ident.name);
282 let def_id = item.owner_id.to_def_id();
283 let is_pub = self.cx.tcx.visibility(def_id).is_public();
286 self.store_path(item.owner_id.to_def_id());
290 hir::ItemKind::ForeignMod { items, .. } => {
292 let item = self.cx.tcx.hir().foreign_item(item.id);
293 self.visit_foreign_item(item, None, om);
296 // If we're inlining, skip private items or item reexported as "_".
297 _ if self.inlining && (!is_pub || renamed == Some(kw::Underscore)) => {}
298 hir::ItemKind::GlobalAsm(..) => {}
299 hir::ItemKind::Use(_, hir::UseKind::ListStem) => {}
300 hir::ItemKind::Use(path, kind) => {
301 let is_glob = kind == hir::UseKind::Glob;
303 // Struct and variant constructors and proc macro stubs always show up alongside
304 // their definitions, we've already processed them so just discard these.
305 if let Res::Def(DefKind::Ctor(..), _) | Res::SelfCtor(..) = path.res {
309 let attrs = self.cx.tcx.hir().attrs(item.hir_id());
311 // If there was a private module in the current path then don't bother inlining
312 // anything as it will probably be stripped anyway.
313 if is_pub && self.inside_public_path {
314 let please_inline = attrs.iter().any(|item| match item.meta_item_list() {
315 Some(ref list) if item.has_name(sym::doc) => {
316 list.iter().any(|i| i.has_name(sym::inline))
320 let ident = if is_glob { None } else { Some(name) };
321 if self.maybe_inline_local(
333 om.items.push((item, renamed))
335 hir::ItemKind::Macro(ref macro_def, _) => {
336 // `#[macro_export] macro_rules!` items are handled separately in `visit()`,
337 // above, since they need to be documented at the module top level. Accordingly,
338 // we only want to handle macros if one of three conditions holds:
340 // 1. This macro was defined by `macro`, and thus isn't covered by the case
342 // 2. This macro isn't marked with `#[macro_export]`, and thus isn't covered
343 // by the case above.
344 // 3. We're inlining, since a reexport where inlining has been requested
345 // should be inlined even if it is also documented at the top level.
347 let def_id = item.owner_id.to_def_id();
348 let is_macro_2_0 = !macro_def.macro_rules;
349 let nonexported = !self.cx.tcx.has_attr(def_id, sym::macro_export);
351 if is_macro_2_0 || nonexported || self.inlining {
352 om.items.push((item, renamed));
355 hir::ItemKind::Mod(ref m) => {
356 om.mods.push(self.visit_mod_contents(item.hir_id(), m, name));
358 hir::ItemKind::Fn(..)
359 | hir::ItemKind::ExternCrate(..)
360 | hir::ItemKind::Enum(..)
361 | hir::ItemKind::Struct(..)
362 | hir::ItemKind::Union(..)
363 | hir::ItemKind::TyAlias(..)
364 | hir::ItemKind::OpaqueTy(..)
365 | hir::ItemKind::Static(..)
366 | hir::ItemKind::Trait(..)
367 | hir::ItemKind::TraitAlias(..) => om.items.push((item, renamed)),
368 hir::ItemKind::Const(..) => {
369 // Underscore constants do not correspond to a nameable item and
370 // so are never useful in documentation.
371 if name != kw::Underscore {
372 om.items.push((item, renamed));
375 hir::ItemKind::Impl(impl_) => {
376 // Don't duplicate impls when inlining or if it's implementing a trait, we'll pick
377 // them up regardless of where they're located.
378 if !self.inlining && impl_.of_trait.is_none() {
379 om.items.push((item, None));
385 fn visit_foreign_item(
387 item: &'tcx hir::ForeignItem<'_>,
388 renamed: Option<Symbol>,
389 om: &mut Module<'tcx>,
391 // If inlining we only want to include public functions.
392 if !self.inlining || self.cx.tcx.visibility(item.owner_id).is_public() {
393 om.foreigns.push((item, renamed));