src/librustc_passes/hir_id_validator.rs

   1 use rustc_data_structures::fx::FxHashSet;
   2 use rustc_data_structures::sync::{par_iter, Lock, ParallelIterator};
   3 use rustc_hir as hir;
   4 use rustc_hir::def_id::{LocalDefId, CRATE_DEF_INDEX};
   5 use rustc_hir::intravisit;
   6 use rustc_hir::itemlikevisit::ItemLikeVisitor;
   7 use rustc_hir::{HirId, ItemLocalId};
   8 use rustc_middle::hir::map::Map;
   9 use rustc_middle::ty::TyCtxt;
  10
  11 pub fn check_crate(tcx: TyCtxt<'_>) {
  12     tcx.dep_graph.assert_ignored();
  13
  14     let errors = Lock::new(Vec::new());
  15     let hir_map = tcx.hir();
  16
  17     par_iter(&hir_map.krate().modules).for_each(|(module_id, _)| {
  18         let local_def_id = hir_map.local_def_id(*module_id);
  19         hir_map.visit_item_likes_in_module(
  20             local_def_id,
  21             &mut OuterVisitor { hir_map, errors: &errors },
  22         );
  23     });
  24
  25     let errors = errors.into_inner();
  26
  27     if !errors.is_empty() {
  28         let message = errors.iter().fold(String::new(), |s1, s2| s1 + "\n" + s2);
  29         tcx.sess.delay_span_bug(rustc_span::DUMMY_SP, &message);
  30     }
  31 }
  32
  33 struct HirIdValidator<'a, 'hir> {
  34     hir_map: Map<'hir>,
  35     owner: Option<LocalDefId>,
  36     hir_ids_seen: FxHashSet<ItemLocalId>,
  37     errors: &'a Lock<Vec<String>>,
  38 }
  39
  40 struct OuterVisitor<'a, 'hir> {
  41     hir_map: Map<'hir>,
  42     errors: &'a Lock<Vec<String>>,
  43 }
  44
  45 impl<'a, 'hir> OuterVisitor<'a, 'hir> {
  46     fn new_inner_visitor(&self, hir_map: Map<'hir>) -> HirIdValidator<'a, 'hir> {
  47         HirIdValidator {
  48             hir_map,
  49             owner: None,
  50             hir_ids_seen: Default::default(),
  51             errors: self.errors,
  52         }
  53     }
  54 }
  55
  56 impl<'a, 'hir> ItemLikeVisitor<'hir> for OuterVisitor<'a, 'hir> {
  57     fn visit_item(&mut self, i: &'hir hir::Item<'hir>) {
  58         let mut inner_visitor = self.new_inner_visitor(self.hir_map);
  59         inner_visitor.check(i.hir_id, |this| intravisit::walk_item(this, i));
  60     }
  61
  62     fn visit_trait_item(&mut self, i: &'hir hir::TraitItem<'hir>) {
  63         let mut inner_visitor = self.new_inner_visitor(self.hir_map);
  64         inner_visitor.check(i.hir_id, |this| intravisit::walk_trait_item(this, i));
  65     }
  66
  67     fn visit_impl_item(&mut self, i: &'hir hir::ImplItem<'hir>) {
  68         let mut inner_visitor = self.new_inner_visitor(self.hir_map);
  69         inner_visitor.check(i.hir_id, |this| intravisit::walk_impl_item(this, i));
  70     }
  71 }
  72
  73 impl<'a, 'hir> HirIdValidator<'a, 'hir> {
  74     #[cold]
  75     #[inline(never)]
  76     fn error(&self, f: impl FnOnce() -> String) {
  77         self.errors.lock().push(f());
  78     }
  79
  80     fn check<F: FnOnce(&mut HirIdValidator<'a, 'hir>)>(&mut self, hir_id: HirId, walk: F) {
  81         assert!(self.owner.is_none());
  82         let owner = self.hir_map.local_def_id(hir_id);
  83         self.owner = Some(owner);
  84         walk(self);
  85
  86         if owner.local_def_index == CRATE_DEF_INDEX {
  87             return;
  88         }
  89
  90         // There's always at least one entry for the owning item itself
  91         let max = self
  92             .hir_ids_seen
  93             .iter()
  94             .map(|local_id| local_id.as_usize())
  95             .max()
  96             .expect("owning item has no entry");
  97
  98         if max != self.hir_ids_seen.len() - 1 {
  99             // Collect the missing ItemLocalIds
 100             let missing: Vec<_> = (0..=max as u32)
 101                 .filter(|&i| !self.hir_ids_seen.contains(&ItemLocalId::from_u32(i)))
 102                 .collect();
 103
 104             // Try to map those to something more useful
 105             let mut missing_items = Vec::with_capacity(missing.len());
 106
 107             for local_id in missing {
 108                 let hir_id = HirId { owner, local_id: ItemLocalId::from_u32(local_id) };
 109
 110                 trace!("missing hir id {:#?}", hir_id);
 111
 112                 missing_items.push(format!(
 113                     "[local_id: {}, owner: {}]",
 114                     local_id,
 115                     self.hir_map.def_path(owner).to_string_no_crate()
 116                 ));
 117             }
 118             self.error(|| {
 119                 format!(
 120                     "ItemLocalIds not assigned densely in {}. \
 121                 Max ItemLocalId = {}, missing IDs = {:?}; seens IDs = {:?}",
 122                     self.hir_map.def_path(owner).to_string_no_crate(),
 123                     max,
 124                     missing_items,
 125                     self.hir_ids_seen
 126                         .iter()
 127                         .map(|&local_id| HirId { owner, local_id })
 128                         .map(|h| format!("({:?} {})", h, self.hir_map.node_to_string(h)))
 129                         .collect::<Vec<_>>()
 130                 )
 131             });
 132         }
 133     }
 134 }
 135
 136 impl<'a, 'hir> intravisit::Visitor<'hir> for HirIdValidator<'a, 'hir> {
 137     type Map = Map<'hir>;
 138
 139     fn nested_visit_map(&mut self) -> intravisit::NestedVisitorMap<Self::Map> {
 140         intravisit::NestedVisitorMap::OnlyBodies(self.hir_map)
 141     }
 142
 143     fn visit_id(&mut self, hir_id: HirId) {
 144         let owner = self.owner.expect("no owner");
 145
 146         if owner != hir_id.owner {
 147             self.error(|| {
 148                 format!(
 149                     "HirIdValidator: The recorded owner of {} is {} instead of {}",
 150                     self.hir_map.node_to_string(hir_id),
 151                     self.hir_map.def_path(hir_id.owner).to_string_no_crate(),
 152                     self.hir_map.def_path(owner).to_string_no_crate()
 153                 )
 154             });
 155         }
 156
 157         self.hir_ids_seen.insert(hir_id.local_id);
 158     }
 159
 160     fn visit_impl_item_ref(&mut self, _: &'hir hir::ImplItemRef<'hir>) {
 161         // Explicitly do nothing here. ImplItemRefs contain hir::Visibility
 162         // values that actually belong to an ImplItem instead of the ItemKind::Impl
 163         // we are currently in. So for those it's correct that they have a
 164         // different owner.
 165     }
 166 }