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::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.item.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),
82 // Attach the crate's exported macros to the top-level module.
83 // In the case of macros 2.0 (`pub macro`), and for built-in `derive`s or attributes as
84 // well (_e.g._, `Copy`), these are wrongly bundled in there too, so we need to fix that by
85 // moving them back to their correct locations.
86 'exported_macros: for def in krate.exported_macros {
87 // The `def` of a macro in `exported_macros` should correspond to either:
88 // - a `#[macro_export] macro_rules!` macro,
89 // - a built-in `derive` (or attribute) macro such as the ones in `::core`,
91 // Only the last two need to be fixed, thus:
92 if def.ast.macro_rules {
93 top_level_module.macros.push((def, None));
94 continue 'exported_macros;
96 let tcx = self.cx.tcx;
97 // Note: this is not the same as `.parent_module()`. Indeed, the latter looks
98 // for the closest module _ancestor_, which is not necessarily a direct parent
99 // (since a direct parent isn't necessarily a module, c.f. #77828).
100 let macro_parent_def_id = {
101 use rustc_middle::ty::DefIdTree;
102 tcx.parent(def.def_id.to_def_id()).unwrap()
104 let macro_parent_path = tcx.def_path(macro_parent_def_id);
105 // HACK: rustdoc has no way to lookup `doctree::Module`s by their HirId. Instead,
106 // lookup the module by its name, by looking at each path segment one at a time.
107 let mut cur_mod = &mut top_level_module;
108 for path_segment in macro_parent_path.data {
109 // Path segments may refer to a module (in which case they belong to the type
110 // namespace), which is _necessary_ for the macro to be accessible outside it
111 // (no "associated macros" as of yet). Else we bail with an outer `continue`.
112 let path_segment_ty_ns = match path_segment.data {
113 rustc_hir::definitions::DefPathData::TypeNs(symbol) => symbol,
114 _ => continue 'exported_macros,
116 // Descend into the child module that matches this path segment (if any).
117 match cur_mod.mods.iter_mut().find(|child| child.name == path_segment_ty_ns) {
118 Some(child_mod) => cur_mod = &mut *child_mod,
119 None => continue 'exported_macros,
122 let cur_mod_def_id = tcx.hir().local_def_id(cur_mod.id).to_def_id();
123 assert_eq!(cur_mod_def_id, macro_parent_def_id);
124 cur_mod.macros.push((def, None));
126 self.cx.cache.exact_paths = self.exact_paths;
130 fn visit_mod_contents(
132 vis: &hir::Visibility<'_>,
134 m: &'tcx hir::Mod<'tcx>,
137 let mut om = Module::new(name, id, m.inner);
138 // Keep track of if there were any private modules in the path.
139 let orig_inside_public_path = self.inside_public_path;
140 self.inside_public_path &= vis.node.is_pub();
141 for &i in m.item_ids {
142 let item = self.cx.tcx.hir().item(i);
143 self.visit_item(item, None, &mut om);
145 self.inside_public_path = orig_inside_public_path;
149 /// Tries to resolve the target of a `pub use` statement and inlines the
150 /// target if it is defined locally and would not be documented otherwise,
151 /// or when it is specifically requested with `please_inline`.
152 /// (the latter is the case when the import is marked `doc(inline)`)
154 /// Cross-crate inlining occurs later on during crate cleaning
155 /// and follows different rules.
157 /// Returns `true` if the target has been inlined.
158 fn maybe_inline_local(
162 renamed: Option<Symbol>,
164 om: &mut Module<'tcx>,
167 debug!("maybe_inline_local res: {:?}", res);
169 let tcx = self.cx.tcx;
170 let res_did = if let Some(did) = res.opt_def_id() {
176 let use_attrs = tcx.hir().attrs(id);
177 // Don't inline `doc(hidden)` imports so they can be stripped at a later stage.
178 let is_no_inline = use_attrs.lists(sym::doc).has_word(sym::no_inline)
179 || use_attrs.lists(sym::doc).has_word(sym::hidden);
181 // For cross-crate impl inlining we need to know whether items are
182 // reachable in documentation -- a previously unreachable item can be
183 // made reachable by cross-crate inlining which we're checking here.
184 // (this is done here because we need to know this upfront).
185 if !res_did.is_local() && !is_no_inline {
186 let attrs = clean::inline::load_attrs(self.cx, res_did);
187 let self_is_hidden = attrs.lists(sym::doc).has_word(sym::hidden);
189 if let Res::Def(kind, did) = res {
190 if kind == DefKind::Mod {
191 crate::visit_lib::LibEmbargoVisitor::new(self.cx).visit_mod(did)
193 // All items need to be handled here in case someone wishes to link
194 // to them with intra-doc links
195 self.cx.cache.access_levels.map.insert(did.into(), AccessLevel::Public);
202 let res_hir_id = match res_did.as_local() {
203 Some(n) => tcx.hir().local_def_id_to_hir_id(n),
204 None => return false,
207 let is_private = !self.cx.cache.access_levels.is_public(res_did.into());
208 let is_hidden = inherits_doc_hidden(self.cx.tcx, res_hir_id);
210 // Only inline if requested or if the item would otherwise be stripped.
211 if (!please_inline && !is_private && !is_hidden) || is_no_inline {
215 if !self.view_item_stack.insert(res_hir_id) {
219 let ret = match tcx.hir().get(res_hir_id) {
220 Node::Item(&hir::Item { kind: hir::ItemKind::Mod(ref m), .. }) if glob => {
221 let prev = mem::replace(&mut self.inlining, true);
222 for &i in m.item_ids {
223 let i = self.cx.tcx.hir().item(i);
224 self.visit_item(i, None, om);
226 self.inlining = prev;
229 Node::Item(it) if !glob => {
230 let prev = mem::replace(&mut self.inlining, true);
231 self.visit_item(it, renamed, om);
232 self.inlining = prev;
235 Node::ForeignItem(it) if !glob => {
236 let prev = mem::replace(&mut self.inlining, true);
237 self.visit_foreign_item(it, renamed, om);
238 self.inlining = prev;
241 Node::MacroDef(def) if !glob => {
242 om.macros.push((def, renamed));
247 self.view_item_stack.remove(&res_hir_id);
253 item: &'tcx hir::Item<'_>,
254 renamed: Option<Symbol>,
255 om: &mut Module<'tcx>,
257 debug!("visiting item {:?}", item);
258 let name = renamed.unwrap_or(item.ident.name);
260 if item.vis.node.is_pub() {
261 self.store_path(item.def_id.to_def_id());
265 hir::ItemKind::ForeignMod { items, .. } => {
267 let item = self.cx.tcx.hir().foreign_item(item.id);
268 self.visit_foreign_item(item, None, om);
271 // If we're inlining, skip private items.
272 _ if self.inlining && !item.vis.node.is_pub() => {}
273 hir::ItemKind::GlobalAsm(..) => {}
274 hir::ItemKind::Use(_, hir::UseKind::ListStem) => {}
275 hir::ItemKind::Use(ref path, kind) => {
276 let is_glob = kind == hir::UseKind::Glob;
278 // Struct and variant constructors and proc macro stubs always show up alongside
279 // their definitions, we've already processed them so just discard these.
280 if let Res::Def(DefKind::Ctor(..), _) | Res::SelfCtor(..) = path.res {
284 let attrs = self.cx.tcx.hir().attrs(item.hir_id());
286 // If there was a private module in the current path then don't bother inlining
287 // anything as it will probably be stripped anyway.
288 if item.vis.node.is_pub() && self.inside_public_path {
289 let please_inline = attrs.iter().any(|item| match item.meta_item_list() {
290 Some(ref list) if item.has_name(sym::doc) => {
291 list.iter().any(|i| i.has_name(sym::inline))
295 let ident = if is_glob { None } else { Some(name) };
296 if self.maybe_inline_local(
308 om.items.push((item, renamed))
310 hir::ItemKind::Mod(ref m) => {
311 om.mods.push(self.visit_mod_contents(&item.vis, item.hir_id(), m, name));
313 hir::ItemKind::Fn(..)
314 | hir::ItemKind::ExternCrate(..)
315 | hir::ItemKind::Enum(..)
316 | hir::ItemKind::Struct(..)
317 | hir::ItemKind::Union(..)
318 | hir::ItemKind::TyAlias(..)
319 | hir::ItemKind::OpaqueTy(..)
320 | hir::ItemKind::Static(..)
321 | hir::ItemKind::Trait(..)
322 | hir::ItemKind::TraitAlias(..) => om.items.push((item, renamed)),
323 hir::ItemKind::Const(..) => {
324 // Underscore constants do not correspond to a nameable item and
325 // so are never useful in documentation.
326 if name != kw::Underscore {
327 om.items.push((item, renamed));
330 hir::ItemKind::Impl(ref impl_) => {
331 // Don't duplicate impls when inlining or if it's implementing a trait, we'll pick
332 // them up regardless of where they're located.
333 if !self.inlining && impl_.of_trait.is_none() {
334 om.items.push((item, None));
340 fn visit_foreign_item(
342 item: &'tcx hir::ForeignItem<'_>,
343 renamed: Option<Symbol>,
344 om: &mut Module<'tcx>,
346 // If inlining we only want to include public functions.
347 if !self.inlining || item.vis.node.is_pub() {
348 om.foreigns.push((item, renamed));