src/librustdoc/visit_lib.rs

   1 use rustc_data_structures::fx::FxHashSet;
   2 use rustc_hir::def::{DefKind, Res};
   3 use rustc_hir::def_id::{CrateNum, DefId};
   4 use rustc_middle::middle::privacy::{AccessLevel, AccessLevels};
   5 use rustc_middle::ty::TyCtxt;
   6
   7 // FIXME: this may not be exhaustive, but is sufficient for rustdocs current uses
   8
   9 /// Similar to `librustc_privacy::EmbargoVisitor`, but also takes
  10 /// specific rustdoc annotations into account (i.e., `doc(hidden)`)
  11 pub(crate) struct LibEmbargoVisitor<'a, 'tcx> {
  12     tcx: TyCtxt<'tcx>,
  13     // Accessibility levels for reachable nodes
  14     access_levels: &'a mut AccessLevels<DefId>,
  15     // Previous accessibility level, None means unreachable
  16     prev_level: Option<AccessLevel>,
  17     // Keeps track of already visited modules, in case a module re-exports its parent
  18     visited_mods: FxHashSet<DefId>,
  19 }
  20
  21 impl<'a, 'tcx> LibEmbargoVisitor<'a, 'tcx> {
  22     pub(crate) fn new(cx: &'a mut crate::core::DocContext<'tcx>) -> LibEmbargoVisitor<'a, 'tcx> {
  23         LibEmbargoVisitor {
  24             tcx: cx.tcx,
  25             access_levels: &mut cx.cache.access_levels,
  26             prev_level: Some(AccessLevel::Public),
  27             visited_mods: FxHashSet::default(),
  28         }
  29     }
  30
  31     pub(crate) fn visit_lib(&mut self, cnum: CrateNum) {
  32         let did = cnum.as_def_id();
  33         self.update(did, Some(AccessLevel::Public));
  34         self.visit_mod(did);
  35     }
  36
  37     // Updates node level and returns the updated level
  38     fn update(&mut self, did: DefId, level: Option<AccessLevel>) -> Option<AccessLevel> {
  39         let is_hidden = self.tcx.is_doc_hidden(did);
  40
  41         let old_level = self.access_levels.map.get(&did).cloned();
  42         // Accessibility levels can only grow
  43         if level > old_level && !is_hidden {
  44             self.access_levels.map.insert(did, level.unwrap());
  45             level
  46         } else {
  47             old_level
  48         }
  49     }
  50
  51     pub(crate) fn visit_mod(&mut self, def_id: DefId) {
  52         if !self.visited_mods.insert(def_id) {
  53             return;
  54         }
  55
  56         for item in self.tcx.module_children(def_id).iter() {
  57             if let Some(def_id) = item.res.opt_def_id() {
  58                 if self.tcx.def_key(def_id).parent.map_or(false, |d| d == def_id.index)
  59                     || item.vis.is_public()
  60                 {
  61                     self.visit_item(item.res);
  62                 }
  63             }
  64         }
  65     }
  66
  67     fn visit_item(&mut self, res: Res<!>) {
  68         let def_id = res.def_id();
  69         let vis = self.tcx.visibility(def_id);
  70         let inherited_item_level = if vis.is_public() { self.prev_level } else { None };
  71
  72         let item_level = self.update(def_id, inherited_item_level);
  73
  74         if let Res::Def(DefKind::Mod, _) = res {
  75             let orig_level = self.prev_level;
  76
  77             self.prev_level = item_level;
  78             self.visit_mod(def_id);
  79             self.prev_level = orig_level;
  80         }
  81     }
  82 }