compiler/rustc_middle/src/hir/mod.rs

   1 //! HIR datatypes. See the [rustc dev guide] for more info.
   2 //!
   3 //! [rustc dev guide]: https://rustc-dev-guide.rust-lang.org/hir.html
   4
   5 pub mod map;
   6 pub mod nested_filter;
   7 pub mod place;
   8
   9 use crate::ty::query::Providers;
  10 use crate::ty::{ImplSubject, TyCtxt};
  11 use rustc_data_structures::fingerprint::Fingerprint;
  12 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
  13 use rustc_hir::def_id::{DefId, LocalDefId};
  14 use rustc_hir::*;
  15 use rustc_query_system::ich::StableHashingContext;
  16 use rustc_span::DUMMY_SP;
  17
  18 /// Top-level HIR node for current owner. This only contains the node for which
  19 /// `HirId::local_id == 0`, and excludes bodies.
  20 ///
  21 /// This struct exists to encapsulate all access to the hir_owner query in this module, and to
  22 /// implement HashStable without hashing bodies.
  23 #[derive(Copy, Clone, Debug)]
  24 pub struct Owner<'tcx> {
  25     node: OwnerNode<'tcx>,
  26     hash_without_bodies: Fingerprint,
  27 }
  28
  29 impl<'a, 'tcx> HashStable<StableHashingContext<'a>> for Owner<'tcx> {
  30     #[inline]
  31     fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
  32         let Owner { node: _, hash_without_bodies } = self;
  33         hash_without_bodies.hash_stable(hcx, hasher)
  34     }
  35 }
  36
  37 /// Gather the LocalDefId for each item-like within a module, including items contained within
  38 /// bodies.  The Ids are in visitor order.  This is used to partition a pass between modules.
  39 #[derive(Debug, HashStable)]
  40 pub struct ModuleItems {
  41     submodules: Box<[LocalDefId]>,
  42     items: Box<[ItemId]>,
  43     trait_items: Box<[TraitItemId]>,
  44     impl_items: Box<[ImplItemId]>,
  45     foreign_items: Box<[ForeignItemId]>,
  46 }
  47
  48 impl<'tcx> TyCtxt<'tcx> {
  49     #[inline(always)]
  50     pub fn hir(self) -> map::Map<'tcx> {
  51         map::Map { tcx: self }
  52     }
  53
  54     pub fn parent_module(self, id: HirId) -> LocalDefId {
  55         self.parent_module_from_def_id(id.owner)
  56     }
  57
  58     pub fn impl_subject(self, def_id: DefId) -> ImplSubject<'tcx> {
  59         self.impl_trait_ref(def_id)
  60             .map(ImplSubject::Trait)
  61             .unwrap_or_else(|| ImplSubject::Inherent(self.type_of(def_id)))
  62     }
  63 }
  64
  65 pub fn provide(providers: &mut Providers) {
  66     providers.parent_module_from_def_id = |tcx, id| {
  67         let hir = tcx.hir();
  68         hir.get_module_parent_node(hir.local_def_id_to_hir_id(id))
  69     };
  70     providers.hir_crate = |tcx, ()| tcx.untracked_crate;
  71     providers.crate_hash = map::crate_hash;
  72     providers.hir_module_items = map::hir_module_items;
  73     providers.hir_owner = |tcx, id| {
  74         let owner = tcx.hir_crate(()).owners.get(id)?.as_owner()?;
  75         let node = owner.node();
  76         Some(Owner { node, hash_without_bodies: owner.nodes.hash_without_bodies })
  77     };
  78     providers.local_def_id_to_hir_id = |tcx, id| {
  79         let owner = tcx.hir_crate(()).owners[id].map(|_| ());
  80         match owner {
  81             MaybeOwner::Owner(_) => HirId::make_owner(id),
  82             MaybeOwner::Phantom => bug!("No HirId for {:?}", id),
  83             MaybeOwner::NonOwner(hir_id) => hir_id,
  84         }
  85     };
  86     providers.hir_owner_nodes = |tcx, id| tcx.hir_crate(()).owners[id].map(|i| &i.nodes);
  87     providers.hir_owner_parent = |tcx, id| {
  88         // Accessing the def_key is ok since its value is hashed as part of `id`'s DefPathHash.
  89         let parent = tcx.untracked_resolutions.definitions.def_key(id).parent;
  90         let parent = parent.map_or(CRATE_HIR_ID, |local_def_index| {
  91             let def_id = LocalDefId { local_def_index };
  92             let mut parent_hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
  93             if let Some(local_id) =
  94                 tcx.hir_crate(()).owners[parent_hir_id.owner].unwrap().parenting.get(&id)
  95             {
  96                 parent_hir_id.local_id = *local_id;
  97             }
  98             parent_hir_id
  99         });
 100         parent
 101     };
 102     providers.hir_attrs =
 103         |tcx, id| tcx.hir_crate(()).owners[id].as_owner().map_or(AttributeMap::EMPTY, |o| &o.attrs);
 104     providers.source_span = |tcx, def_id| tcx.resolutions(()).definitions.def_span(def_id);
 105     providers.def_span = |tcx, def_id| tcx.hir().span_if_local(def_id).unwrap_or(DUMMY_SP);
 106     providers.fn_arg_names = |tcx, id| {
 107         let hir = tcx.hir();
 108         let hir_id = hir.local_def_id_to_hir_id(id.expect_local());
 109         if let Some(body_id) = hir.maybe_body_owned_by(hir_id) {
 110             tcx.arena.alloc_from_iter(hir.body_param_names(body_id))
 111         } else if let Node::TraitItem(&TraitItem {
 112             kind: TraitItemKind::Fn(_, TraitFn::Required(idents)),
 113             ..
 114         }) = hir.get(hir_id)
 115         {
 116             tcx.arena.alloc_slice(idents)
 117         } else {
 118             span_bug!(hir.span(hir_id), "fn_arg_names: unexpected item {:?}", id);
 119         }
 120     };
 121     providers.opt_def_kind = |tcx, def_id| tcx.hir().opt_def_kind(def_id.expect_local());
 122     providers.all_local_trait_impls = |tcx, ()| &tcx.resolutions(()).trait_impls;
 123     providers.expn_that_defined = |tcx, id| {
 124         let id = id.expect_local();
 125         tcx.resolutions(()).definitions.expansion_that_defined(id)
 126     };
 127     providers.in_scope_traits_map =
 128         |tcx, id| tcx.hir_crate(()).owners[id].as_owner().map(|owner_info| &owner_info.trait_map);
 129 }