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::middle::privacy::AccessLevel;
11 use rustc_middle::ty::TyCtxt;
13 use rustc_span::def_id::{CRATE_DEF_ID, LOCAL_CRATE};
14 use rustc_span::source_map::Spanned;
15 use rustc_span::symbol::{kw, sym, Symbol};
19 use crate::clean::{self, cfg::Cfg, AttributesExt, NestedAttributesExt};
21 use crate::doctree::*;
23 // FIXME: Should this be replaced with tcx.def_path_str?
24 fn def_id_to_path(tcx: TyCtxt<'_>, did: DefId) -> Vec<String> {
25 let crate_name = tcx.crate_name(did.krate).to_string();
26 let relative = tcx.def_path(did).data.into_iter().filter_map(|elem| {
27 // extern blocks have an empty name
28 let s = elem.data.to_string();
29 if !s.is_empty() { Some(s) } else { None }
31 std::iter::once(crate_name).chain(relative).collect()
34 crate fn inherits_doc_hidden(tcx: TyCtxt<'_>, mut node: hir::HirId) -> bool {
35 while let Some(id) = tcx.hir().get_enclosing_scope(node) {
37 if tcx.hir().attrs(node).lists(sym::doc).has_word(sym::hidden) {
44 // Also, is there some reason that this doesn't use the 'visit'
45 // framework from syntax?.
47 crate struct RustdocVisitor<'a, 'tcx> {
48 cx: &'a mut core::DocContext<'tcx>,
49 view_item_stack: FxHashSet<hir::HirId>,
51 /// Are the current module and all of its parents public?
52 inside_public_path: bool,
53 exact_paths: FxHashMap<DefId, Vec<String>>,
56 impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
57 crate fn new(cx: &'a mut core::DocContext<'tcx>) -> RustdocVisitor<'a, 'tcx> {
58 // If the root is re-exported, terminate all recursion.
59 let mut stack = FxHashSet::default();
60 stack.insert(hir::CRATE_HIR_ID);
63 view_item_stack: stack,
65 inside_public_path: true,
66 exact_paths: FxHashMap::default(),
70 fn store_path(&mut self, did: DefId) {
71 let tcx = self.cx.tcx;
72 self.exact_paths.entry(did).or_insert_with(|| def_id_to_path(tcx, did));
75 crate fn visit(mut self) -> Module<'tcx> {
76 let span = self.cx.tcx.def_span(CRATE_DEF_ID);
77 let mut top_level_module = self.visit_mod_contents(
78 &Spanned { span, node: hir::VisibilityKind::Public },
80 self.cx.tcx.hir().root_module(),
81 self.cx.tcx.crate_name(LOCAL_CRATE),
84 // `#[macro_export] macro_rules!` items are reexported at the top level of the
85 // crate, regardless of where they're defined. We want to document the
86 // top level rexport of the macro, not its original definition, since
87 // the rexport defines the path that a user will actually see. Accordingly,
88 // we add the rexport as an item here, and then skip over the original
89 // definition in `visit_item()` below.
90 for export in self.cx.tcx.module_exports(CRATE_DEF_ID).unwrap_or(&[]) {
91 if let Res::Def(DefKind::Macro(_), def_id) = export.res {
92 if let Some(local_def_id) = def_id.as_local() {
93 if self.cx.tcx.has_attr(def_id, sym::macro_export) {
94 let hir_id = self.cx.tcx.hir().local_def_id_to_hir_id(local_def_id);
95 let item = self.cx.tcx.hir().expect_item(hir_id);
96 top_level_module.items.push((item, None));
102 self.cx.cache.hidden_cfg = self
108 .filter(|attr| attr.has_name(sym::doc))
109 .flat_map(|attr| attr.meta_item_list().into_iter().flatten())
110 .filter(|attr| attr.has_name(sym::cfg_hide))
112 attr.meta_item_list()
116 Cfg::parse(attr.meta_item()?)
117 .map_err(|e| self.cx.sess().diagnostic().span_err(e.span, e.msg))
124 self.cx.cache.exact_paths = self.exact_paths;
128 fn visit_mod_contents(
130 vis: &hir::Visibility<'_>,
132 m: &'tcx hir::Mod<'tcx>,
135 let mut om = Module::new(name, id, m.inner);
136 // Keep track of if there were any private modules in the path.
137 let orig_inside_public_path = self.inside_public_path;
138 self.inside_public_path &= vis.node.is_pub();
139 for &i in m.item_ids {
140 let item = self.cx.tcx.hir().item(i);
141 self.visit_item(item, None, &mut om);
143 self.inside_public_path = orig_inside_public_path;
147 /// Tries to resolve the target of a `pub use` statement and inlines the
148 /// target if it is defined locally and would not be documented otherwise,
149 /// or when it is specifically requested with `please_inline`.
150 /// (the latter is the case when the import is marked `doc(inline)`)
152 /// Cross-crate inlining occurs later on during crate cleaning
153 /// and follows different rules.
155 /// Returns `true` if the target has been inlined.
156 fn maybe_inline_local(
160 renamed: Option<Symbol>,
162 om: &mut Module<'tcx>,
165 debug!("maybe_inline_local res: {:?}", res);
167 let tcx = self.cx.tcx;
168 let res_did = if let Some(did) = res.opt_def_id() {
174 let use_attrs = tcx.hir().attrs(id);
175 // Don't inline `doc(hidden)` imports so they can be stripped at a later stage.
176 let is_no_inline = use_attrs.lists(sym::doc).has_word(sym::no_inline)
177 || use_attrs.lists(sym::doc).has_word(sym::hidden);
179 // For cross-crate impl inlining we need to know whether items are
180 // reachable in documentation -- a previously unreachable item can be
181 // made reachable by cross-crate inlining which we're checking here.
182 // (this is done here because we need to know this upfront).
183 if !res_did.is_local() && !is_no_inline {
184 let attrs = clean::inline::load_attrs(self.cx, res_did);
185 let self_is_hidden = attrs.lists(sym::doc).has_word(sym::hidden);
187 if let Res::Def(kind, did) = res {
188 if kind == DefKind::Mod {
189 crate::visit_lib::LibEmbargoVisitor::new(self.cx).visit_mod(did)
191 // All items need to be handled here in case someone wishes to link
192 // to them with intra-doc links
193 self.cx.cache.access_levels.map.insert(did, AccessLevel::Public);
200 let res_hir_id = match res_did.as_local() {
201 Some(n) => tcx.hir().local_def_id_to_hir_id(n),
202 None => return false,
205 let is_private = !self.cx.cache.access_levels.is_public(res_did);
206 let is_hidden = inherits_doc_hidden(self.cx.tcx, res_hir_id);
208 // Only inline if requested or if the item would otherwise be stripped.
209 if (!please_inline && !is_private && !is_hidden) || is_no_inline {
213 if !self.view_item_stack.insert(res_hir_id) {
217 let ret = match tcx.hir().get(res_hir_id) {
218 Node::Item(&hir::Item { kind: hir::ItemKind::Mod(ref m), .. }) if glob => {
219 let prev = mem::replace(&mut self.inlining, true);
220 for &i in m.item_ids {
221 let i = self.cx.tcx.hir().item(i);
222 self.visit_item(i, None, om);
224 self.inlining = prev;
227 Node::Item(it) if !glob => {
228 let prev = mem::replace(&mut self.inlining, true);
229 self.visit_item(it, renamed, om);
230 self.inlining = prev;
233 Node::ForeignItem(it) if !glob => {
234 let prev = mem::replace(&mut self.inlining, true);
235 self.visit_foreign_item(it, renamed, om);
236 self.inlining = prev;
241 self.view_item_stack.remove(&res_hir_id);
247 item: &'tcx hir::Item<'_>,
248 renamed: Option<Symbol>,
249 om: &mut Module<'tcx>,
251 debug!("visiting item {:?}", item);
252 let name = renamed.unwrap_or(item.ident.name);
254 let def_id = item.def_id.to_def_id();
255 let is_pub = item.vis.node.is_pub() || self.cx.tcx.has_attr(def_id, sym::macro_export);
258 self.store_path(item.def_id.to_def_id());
262 hir::ItemKind::ForeignMod { items, .. } => {
264 let item = self.cx.tcx.hir().foreign_item(item.id);
265 self.visit_foreign_item(item, None, om);
268 // If we're inlining, skip private items.
269 _ if self.inlining && !is_pub => {}
270 hir::ItemKind::GlobalAsm(..) => {}
271 hir::ItemKind::Use(_, hir::UseKind::ListStem) => {}
272 hir::ItemKind::Use(ref path, kind) => {
273 let is_glob = kind == hir::UseKind::Glob;
275 // Struct and variant constructors and proc macro stubs always show up alongside
276 // their definitions, we've already processed them so just discard these.
277 if let Res::Def(DefKind::Ctor(..), _) | Res::SelfCtor(..) = path.res {
281 let attrs = self.cx.tcx.hir().attrs(item.hir_id());
283 // If there was a private module in the current path then don't bother inlining
284 // anything as it will probably be stripped anyway.
285 if is_pub && self.inside_public_path {
286 let please_inline = attrs.iter().any(|item| match item.meta_item_list() {
287 Some(ref list) if item.has_name(sym::doc) => {
288 list.iter().any(|i| i.has_name(sym::inline))
292 let ident = if is_glob { None } else { Some(name) };
293 if self.maybe_inline_local(
305 om.items.push((item, renamed))
307 hir::ItemKind::Macro(ref macro_def) => {
308 // `#[macro_export] macro_rules!` items are handled seperately in `visit()`,
309 // above, since they need to be documented at the module top level. Accordingly,
310 // we only want to handle macros if one of three conditions holds:
312 // 1. This macro was defined by `macro`, and thus isn't covered by the case
314 // 2. This macro isn't marked with `#[macro_export]`, and thus isn't covered
315 // by the case above.
316 // 3. We're inlining, since a reexport where inlining has been requested
317 // should be inlined even if it is also documented at the top level.
319 let def_id = item.def_id.to_def_id();
320 let is_macro_2_0 = !macro_def.macro_rules;
321 let nonexported = !self.cx.tcx.has_attr(def_id, sym::macro_export);
323 if is_macro_2_0 || nonexported || self.inlining {
324 om.items.push((item, renamed));
327 hir::ItemKind::Mod(ref m) => {
328 om.mods.push(self.visit_mod_contents(&item.vis, item.hir_id(), m, name));
330 hir::ItemKind::Fn(..)
331 | hir::ItemKind::ExternCrate(..)
332 | hir::ItemKind::Enum(..)
333 | hir::ItemKind::Struct(..)
334 | hir::ItemKind::Union(..)
335 | hir::ItemKind::TyAlias(..)
336 | hir::ItemKind::OpaqueTy(..)
337 | hir::ItemKind::Static(..)
338 | hir::ItemKind::Trait(..)
339 | hir::ItemKind::TraitAlias(..) => om.items.push((item, renamed)),
340 hir::ItemKind::Const(..) => {
341 // Underscore constants do not correspond to a nameable item and
342 // so are never useful in documentation.
343 if name != kw::Underscore {
344 om.items.push((item, renamed));
347 hir::ItemKind::Impl(ref impl_) => {
348 // Don't duplicate impls when inlining or if it's implementing a trait, we'll pick
349 // them up regardless of where they're located.
350 if !self.inlining && impl_.of_trait.is_none() {
351 om.items.push((item, None));
357 fn visit_foreign_item(
359 item: &'tcx hir::ForeignItem<'_>,
360 renamed: Option<Symbol>,
361 om: &mut Module<'tcx>,
363 // If inlining we only want to include public functions.
364 if !self.inlining || item.vis.node.is_pub() {
365 om.foreigns.push((item, renamed));