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 crate fn inherits_doc_hidden(tcx: TyCtxt<'_>, mut node: hir::HirId) -> bool {
33 while let Some(id) = tcx.hir().get_enclosing_scope(node) {
35 if tcx.hir().attrs(node).lists(sym::doc).has_word(sym::hidden) {
42 // Also, is there some reason that this doesn't use the 'visit'
43 // framework from syntax?.
45 crate struct RustdocVisitor<'a, 'tcx> {
46 cx: &'a mut core::DocContext<'tcx>,
47 view_item_stack: FxHashSet<hir::HirId>,
49 /// Are the current module and all of its parents public?
50 inside_public_path: bool,
51 exact_paths: FxHashMap<DefId, Vec<String>>,
54 impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
55 crate fn new(cx: &'a mut core::DocContext<'tcx>) -> RustdocVisitor<'a, 'tcx> {
56 // If the root is re-exported, terminate all recursion.
57 let mut stack = FxHashSet::default();
58 stack.insert(hir::CRATE_HIR_ID);
61 view_item_stack: stack,
63 inside_public_path: true,
64 exact_paths: FxHashMap::default(),
68 fn store_path(&mut self, did: DefId) {
69 let tcx = self.cx.tcx;
70 self.exact_paths.entry(did).or_insert_with(|| def_id_to_path(tcx, did));
73 crate fn visit(mut self, krate: &'tcx hir::Crate<'_>) -> Module<'tcx> {
74 let mut top_level_module = self.visit_mod_contents(
76 &Spanned { span: rustc_span::DUMMY_SP, node: hir::VisibilityKind::Public },
79 self.cx.tcx.crate_name,
81 top_level_module.is_crate = true;
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(
133 vis: &'tcx hir::Visibility<'_>,
135 m: &'tcx hir::Mod<'tcx>,
138 let mut om = Module::new(name);
139 om.where_outer = span;
140 om.where_inner = m.inner;
142 // Keep track of if there were any private modules in the path.
143 let orig_inside_public_path = self.inside_public_path;
144 self.inside_public_path &= vis.node.is_pub();
145 for &i in m.item_ids {
146 let item = self.cx.tcx.hir().item(i);
147 self.visit_item(item, None, &mut om);
149 self.inside_public_path = orig_inside_public_path;
153 /// Tries to resolve the target of a `crate use` statement and inlines the
154 /// target if it is defined locally and would not be documented otherwise,
155 /// or when it is specifically requested with `please_inline`.
156 /// (the latter is the case when the import is marked `doc(inline)`)
158 /// Cross-crate inlining occurs later on during crate cleaning
159 /// and follows different rules.
161 /// Returns `true` if the target has been inlined.
162 fn maybe_inline_local(
166 renamed: Option<Symbol>,
168 om: &mut Module<'tcx>,
171 debug!("maybe_inline_local res: {:?}", res);
173 let tcx = self.cx.tcx;
174 let res_did = if let Some(did) = res.opt_def_id() {
180 let use_attrs = tcx.hir().attrs(id);
181 // Don't inline `doc(hidden)` imports so they can be stripped at a later stage.
182 let is_no_inline = use_attrs.lists(sym::doc).has_word(sym::no_inline)
183 || use_attrs.lists(sym::doc).has_word(sym::hidden);
185 // For cross-crate impl inlining we need to know whether items are
186 // reachable in documentation -- a previously nonreachable item can be
187 // made reachable by cross-crate inlining which we're checking here.
188 // (this is done here because we need to know this upfront).
189 if !res_did.is_local() && !is_no_inline {
190 let attrs = clean::inline::load_attrs(self.cx, res_did);
191 let self_is_hidden = attrs.lists(sym::doc).has_word(sym::hidden);
193 if let Res::Def(kind, did) = res {
194 if kind == DefKind::Mod {
195 crate::visit_lib::LibEmbargoVisitor::new(self.cx).visit_mod(did)
197 // All items need to be handled here in case someone wishes to link
198 // to them with intra-doc links
199 self.cx.cache.access_levels.map.insert(did, AccessLevel::Public);
206 let res_hir_id = match res_did.as_local() {
207 Some(n) => tcx.hir().local_def_id_to_hir_id(n),
208 None => return false,
211 let is_private = !self.cx.cache.access_levels.is_public(res_did);
212 let is_hidden = inherits_doc_hidden(self.cx.tcx, res_hir_id);
214 // Only inline if requested or if the item would otherwise be stripped.
215 if (!please_inline && !is_private && !is_hidden) || is_no_inline {
219 if !self.view_item_stack.insert(res_hir_id) {
223 let ret = match tcx.hir().get(res_hir_id) {
224 Node::Item(&hir::Item { kind: hir::ItemKind::Mod(ref m), .. }) if glob => {
225 let prev = mem::replace(&mut self.inlining, true);
226 for &i in m.item_ids {
227 let i = self.cx.tcx.hir().item(i);
228 self.visit_item(i, None, om);
230 self.inlining = prev;
233 Node::Item(it) if !glob => {
234 let prev = mem::replace(&mut self.inlining, true);
235 self.visit_item(it, renamed, om);
236 self.inlining = prev;
239 Node::ForeignItem(it) if !glob => {
240 let prev = mem::replace(&mut self.inlining, true);
241 self.visit_foreign_item(it, renamed, om);
242 self.inlining = prev;
245 Node::MacroDef(def) if !glob => {
246 om.macros.push((def, renamed));
251 self.view_item_stack.remove(&res_hir_id);
257 item: &'tcx hir::Item<'_>,
258 renamed: Option<Symbol>,
259 om: &mut Module<'tcx>,
261 debug!("visiting item {:?}", item);
262 let name = renamed.unwrap_or(item.ident.name);
264 if item.vis.node.is_pub() {
265 self.store_path(item.def_id.to_def_id());
269 hir::ItemKind::ForeignMod { items, .. } => {
271 let item = self.cx.tcx.hir().foreign_item(item.id);
272 self.visit_foreign_item(item, None, om);
275 // If we're inlining, skip private items.
276 _ if self.inlining && !item.vis.node.is_pub() => {}
277 hir::ItemKind::GlobalAsm(..) => {}
278 hir::ItemKind::Use(_, hir::UseKind::ListStem) => {}
279 hir::ItemKind::Use(ref path, kind) => {
280 let is_glob = kind == hir::UseKind::Glob;
282 // Struct and variant constructors and proc macro stubs always show up alongside
283 // their definitions, we've already processed them so just discard these.
284 if let Res::Def(DefKind::Ctor(..), _) | Res::SelfCtor(..) = path.res {
288 let attrs = self.cx.tcx.hir().attrs(item.hir_id());
290 // If there was a private module in the current path then don't bother inlining
291 // anything as it will probably be stripped anyway.
292 if item.vis.node.is_pub() && self.inside_public_path {
293 let please_inline = attrs.iter().any(|item| match item.meta_item_list() {
294 Some(ref list) if item.has_name(sym::doc) => {
295 list.iter().any(|i| i.has_name(sym::inline))
299 let ident = if is_glob { None } else { Some(name) };
300 if self.maybe_inline_local(
312 om.items.push((item, renamed))
314 hir::ItemKind::Mod(ref m) => {
315 om.mods.push(self.visit_mod_contents(item.span, &item.vis, item.hir_id(), m, name));
317 hir::ItemKind::Fn(..)
318 | hir::ItemKind::ExternCrate(..)
319 | hir::ItemKind::Enum(..)
320 | hir::ItemKind::Struct(..)
321 | hir::ItemKind::Union(..)
322 | hir::ItemKind::TyAlias(..)
323 | hir::ItemKind::OpaqueTy(..)
324 | hir::ItemKind::Static(..)
325 | hir::ItemKind::Trait(..)
326 | hir::ItemKind::TraitAlias(..) => om.items.push((item, renamed)),
327 hir::ItemKind::Const(..) => {
328 // Underscore constants do not correspond to a nameable item and
329 // so are never useful in documentation.
330 if name != kw::Underscore {
331 om.items.push((item, renamed));
334 hir::ItemKind::Impl(ref impl_) => {
335 // Don't duplicate impls when inlining or if it's implementing a trait, we'll pick
336 // them up regardless of where they're located.
337 if !self.inlining && impl_.of_trait.is_none() {
338 om.items.push((item, None));
344 fn visit_foreign_item(
346 item: &'tcx hir::ForeignItem<'_>,
347 renamed: Option<Symbol>,
348 om: &mut Module<'tcx>,
350 // If inlining we only want to include public functions.
351 if !self.inlining || item.vis.node.is_pub() {
352 om.foreigns.push((item, renamed));