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()
117 Cfg::parse(attr.meta_item()?)
118 .map_err(|e| self.cx.sess().diagnostic().span_err(e.span, e.msg))
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, 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);
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;
243 self.view_item_stack.remove(&res_hir_id);
249 item: &'tcx hir::Item<'_>,
250 renamed: Option<Symbol>,
251 om: &mut Module<'tcx>,
253 debug!("visiting item {:?}", item);
254 let name = renamed.unwrap_or(item.ident.name);
256 let def_id = item.def_id.to_def_id();
257 let is_pub = item.vis.node.is_pub() || self.cx.tcx.has_attr(def_id, sym::macro_export);
260 self.store_path(item.def_id.to_def_id());
264 hir::ItemKind::ForeignMod { items, .. } => {
266 let item = self.cx.tcx.hir().foreign_item(item.id);
267 self.visit_foreign_item(item, None, om);
270 // If we're inlining, skip private items.
271 _ if self.inlining && !is_pub => {}
272 hir::ItemKind::GlobalAsm(..) => {}
273 hir::ItemKind::Use(_, hir::UseKind::ListStem) => {}
274 hir::ItemKind::Use(ref path, kind) => {
275 let is_glob = kind == hir::UseKind::Glob;
277 // Struct and variant constructors and proc macro stubs always show up alongside
278 // their definitions, we've already processed them so just discard these.
279 if let Res::Def(DefKind::Ctor(..), _) | Res::SelfCtor(..) = path.res {
283 let attrs = self.cx.tcx.hir().attrs(item.hir_id());
285 // If there was a private module in the current path then don't bother inlining
286 // anything as it will probably be stripped anyway.
287 if is_pub && self.inside_public_path {
288 let please_inline = attrs.iter().any(|item| match item.meta_item_list() {
289 Some(ref list) if item.has_name(sym::doc) => {
290 list.iter().any(|i| i.has_name(sym::inline))
294 let ident = if is_glob { None } else { Some(name) };
295 if self.maybe_inline_local(
307 om.items.push((item, renamed))
309 hir::ItemKind::Macro(ref macro_def) => {
310 // `#[macro_export] macro_rules!` items are handled seperately in `visit()`,
311 // above, since they need to be documented at the module top level. Accordingly,
312 // we only want to handle macros if one of three conditions holds:
314 // 1. This macro was defined by `macro`, and thus isn't covered by the case
316 // 2. This macro isn't marked with `#[macro_export]`, and thus isn't covered
317 // by the case above.
318 // 3. We're inlining, since a reexport where inlining has been requested
319 // should be inlined even if it is also documented at the top level.
321 let def_id = item.def_id.to_def_id();
322 let is_macro_2_0 = !macro_def.macro_rules;
323 let nonexported = !self.cx.tcx.has_attr(def_id, sym::macro_export);
325 if is_macro_2_0 || nonexported || self.inlining {
326 om.items.push((item, renamed));
329 hir::ItemKind::Mod(ref m) => {
330 om.mods.push(self.visit_mod_contents(&item.vis, item.hir_id(), m, name));
332 hir::ItemKind::Fn(..)
333 | hir::ItemKind::ExternCrate(..)
334 | hir::ItemKind::Enum(..)
335 | hir::ItemKind::Struct(..)
336 | hir::ItemKind::Union(..)
337 | hir::ItemKind::TyAlias(..)
338 | hir::ItemKind::OpaqueTy(..)
339 | hir::ItemKind::Static(..)
340 | hir::ItemKind::Trait(..)
341 | hir::ItemKind::TraitAlias(..) => om.items.push((item, renamed)),
342 hir::ItemKind::Const(..) => {
343 // Underscore constants do not correspond to a nameable item and
344 // so are never useful in documentation.
345 if name != kw::Underscore {
346 om.items.push((item, renamed));
349 hir::ItemKind::Impl(ref impl_) => {
350 // Don't duplicate impls when inlining or if it's implementing a trait, we'll pick
351 // them up regardless of where they're located.
352 if !self.inlining && impl_.of_trait.is_none() {
353 om.items.push((item, None));
359 fn visit_foreign_item(
361 item: &'tcx hir::ForeignItem<'_>,
362 renamed: Option<Symbol>,
363 om: &mut Module<'tcx>,
365 // If inlining we only want to include public functions.
366 if !self.inlining || item.vis.node.is_pub() {
367 om.foreigns.push((item, renamed));