compiler/rustc_middle/src/hir/map/collector.rs

   1 use crate::arena::Arena;
   2 use crate::hir::map::{Entry, HirOwnerData, Map};
   3 use crate::hir::{Owner, OwnerNodes, ParentedNode};
   4 use crate::ich::StableHashingContext;
   5 use crate::middle::cstore::CrateStore;
   6 use rustc_data_structures::fingerprint::Fingerprint;
   7 use rustc_data_structures::fx::FxHashMap;
   8 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
   9 use rustc_data_structures::svh::Svh;
  10 use rustc_hir as hir;
  11 use rustc_hir::def_id::CRATE_DEF_INDEX;
  12 use rustc_hir::def_id::{LocalDefId, LOCAL_CRATE};
  13 use rustc_hir::definitions::{self, DefPathHash};
  14 use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor};
  15 use rustc_hir::*;
  16 use rustc_index::vec::{Idx, IndexVec};
  17 use rustc_session::{CrateDisambiguator, Session};
  18 use rustc_span::source_map::SourceMap;
  19 use rustc_span::{Span, Symbol, DUMMY_SP};
  20
  21 use std::iter::repeat;
  22
  23 /// A visitor that walks over the HIR and collects `Node`s into a HIR map.
  24 pub(super) struct NodeCollector<'a, 'hir> {
  25     arena: &'hir Arena<'hir>,
  26
  27     /// The crate
  28     krate: &'hir Crate<'hir>,
  29
  30     /// Source map
  31     source_map: &'a SourceMap,
  32
  33     map: IndexVec<LocalDefId, HirOwnerData<'hir>>,
  34
  35     /// The parent of this node
  36     parent_node: hir::HirId,
  37
  38     current_dep_node_owner: LocalDefId,
  39
  40     definitions: &'a definitions::Definitions,
  41
  42     hcx: StableHashingContext<'a>,
  43
  44     // We are collecting HIR hashes here so we can compute the
  45     // crate hash from them later on.
  46     hir_body_nodes: Vec<(DefPathHash, Fingerprint)>,
  47 }
  48
  49 fn insert_vec_map<K: Idx, V: Clone>(map: &mut IndexVec<K, Option<V>>, k: K, v: V) {
  50     let i = k.index();
  51     let len = map.len();
  52     if i >= len {
  53         map.extend(repeat(None).take(i - len + 1));
  54     }
  55     map[k] = Some(v);
  56 }
  57
  58 fn hash(
  59     hcx: &mut StableHashingContext<'_>,
  60     input: impl for<'a> HashStable<StableHashingContext<'a>>,
  61 ) -> Fingerprint {
  62     let mut stable_hasher = StableHasher::new();
  63     input.hash_stable(hcx, &mut stable_hasher);
  64     stable_hasher.finish()
  65 }
  66
  67 fn hash_body(
  68     hcx: &mut StableHashingContext<'_>,
  69     def_path_hash: DefPathHash,
  70     item_like: impl for<'a> HashStable<StableHashingContext<'a>>,
  71     hir_body_nodes: &mut Vec<(DefPathHash, Fingerprint)>,
  72 ) -> Fingerprint {
  73     let hash = hash(hcx, HirItemLike { item_like: &item_like });
  74     hir_body_nodes.push((def_path_hash, hash));
  75     hash
  76 }
  77
  78 fn upstream_crates(cstore: &dyn CrateStore) -> Vec<(Symbol, Fingerprint, Svh)> {
  79     let mut upstream_crates: Vec<_> = cstore
  80         .crates_untracked()
  81         .iter()
  82         .map(|&cnum| {
  83             let name = cstore.crate_name_untracked(cnum);
  84             let disambiguator = cstore.crate_disambiguator_untracked(cnum).to_fingerprint();
  85             let hash = cstore.crate_hash_untracked(cnum);
  86             (name, disambiguator, hash)
  87         })
  88         .collect();
  89     upstream_crates.sort_unstable_by_key(|&(name, dis, _)| (name.as_str(), dis));
  90     upstream_crates
  91 }
  92
  93 impl<'a, 'hir> NodeCollector<'a, 'hir> {
  94     pub(super) fn root(
  95         sess: &'a Session,
  96         arena: &'hir Arena<'hir>,
  97         krate: &'hir Crate<'hir>,
  98         definitions: &'a definitions::Definitions,
  99         mut hcx: StableHashingContext<'a>,
 100     ) -> NodeCollector<'a, 'hir> {
 101         let root_mod_def_path_hash =
 102             definitions.def_path_hash(LocalDefId { local_def_index: CRATE_DEF_INDEX });
 103
 104         let mut hir_body_nodes = Vec::new();
 105
 106         let hash = {
 107             let Crate {
 108                 ref item,
 109                 // These fields are handled separately:
 110                 exported_macros: _,
 111                 non_exported_macro_attrs: _,
 112                 items: _,
 113                 trait_items: _,
 114                 impl_items: _,
 115                 bodies: _,
 116                 trait_impls: _,
 117                 body_ids: _,
 118                 modules: _,
 119                 proc_macros: _,
 120                 trait_map: _,
 121             } = *krate;
 122
 123             hash_body(&mut hcx, root_mod_def_path_hash, item, &mut hir_body_nodes)
 124         };
 125
 126         let mut collector = NodeCollector {
 127             arena,
 128             krate,
 129             source_map: sess.source_map(),
 130             parent_node: hir::CRATE_HIR_ID,
 131             current_dep_node_owner: LocalDefId { local_def_index: CRATE_DEF_INDEX },
 132             definitions,
 133             hcx,
 134             hir_body_nodes,
 135             map: (0..definitions.def_index_count())
 136                 .map(|_| HirOwnerData { signature: None, with_bodies: None })
 137                 .collect(),
 138         };
 139         collector.insert_entry(
 140             hir::CRATE_HIR_ID,
 141             Entry { parent: hir::CRATE_HIR_ID, node: Node::Crate(&krate.item) },
 142             hash,
 143         );
 144
 145         collector
 146     }
 147
 148     pub(super) fn finalize_and_compute_crate_hash(
 149         mut self,
 150         crate_disambiguator: CrateDisambiguator,
 151         cstore: &dyn CrateStore,
 152         commandline_args_hash: u64,
 153     ) -> (IndexVec<LocalDefId, HirOwnerData<'hir>>, Svh) {
 154         // Insert bodies into the map
 155         for (id, body) in self.krate.bodies.iter() {
 156             let bodies = &mut self.map[id.hir_id.owner].with_bodies.as_mut().unwrap().bodies;
 157             assert!(bodies.insert(id.hir_id.local_id, body).is_none());
 158         }
 159
 160         self.hir_body_nodes.sort_unstable_by_key(|bn| bn.0);
 161
 162         let node_hashes = self.hir_body_nodes.iter().fold(
 163             Fingerprint::ZERO,
 164             |combined_fingerprint, &(def_path_hash, fingerprint)| {
 165                 combined_fingerprint.combine(def_path_hash.0.combine(fingerprint))
 166             },
 167         );
 168
 169         let upstream_crates = upstream_crates(cstore);
 170
 171         // We hash the final, remapped names of all local source files so we
 172         // don't have to include the path prefix remapping commandline args.
 173         // If we included the full mapping in the SVH, we could only have
 174         // reproducible builds by compiling from the same directory. So we just
 175         // hash the result of the mapping instead of the mapping itself.
 176         let mut source_file_names: Vec<_> = self
 177             .source_map
 178             .files()
 179             .iter()
 180             .filter(|source_file| source_file.cnum == LOCAL_CRATE)
 181             .map(|source_file| source_file.name_hash)
 182             .collect();
 183
 184         source_file_names.sort_unstable();
 185
 186         let crate_hash_input = (
 187             ((node_hashes, upstream_crates), source_file_names),
 188             (commandline_args_hash, crate_disambiguator.to_fingerprint()),
 189         );
 190
 191         let mut stable_hasher = StableHasher::new();
 192         crate_hash_input.hash_stable(&mut self.hcx, &mut stable_hasher);
 193         let crate_hash: Fingerprint = stable_hasher.finish();
 194
 195         let svh = Svh::new(crate_hash.to_smaller_hash());
 196         (self.map, svh)
 197     }
 198
 199     fn insert_entry(&mut self, id: HirId, entry: Entry<'hir>, hash: Fingerprint) {
 200         let i = id.local_id.as_u32() as usize;
 201
 202         let arena = self.arena;
 203
 204         let data = &mut self.map[id.owner];
 205
 206         if data.with_bodies.is_none() {
 207             data.with_bodies = Some(arena.alloc(OwnerNodes {
 208                 hash,
 209                 nodes: IndexVec::new(),
 210                 bodies: FxHashMap::default(),
 211             }));
 212         }
 213
 214         let nodes = data.with_bodies.as_mut().unwrap();
 215
 216         if i == 0 {
 217             // Overwrite the dummy hash with the real HIR owner hash.
 218             nodes.hash = hash;
 219
 220             // FIXME: feature(impl_trait_in_bindings) broken and trigger this assert
 221             //assert!(data.signature.is_none());
 222
 223             data.signature =
 224                 Some(self.arena.alloc(Owner { parent: entry.parent, node: entry.node }));
 225         } else {
 226             assert_eq!(entry.parent.owner, id.owner);
 227             insert_vec_map(
 228                 &mut nodes.nodes,
 229                 id.local_id,
 230                 ParentedNode { parent: entry.parent.local_id, node: entry.node },
 231             );
 232         }
 233     }
 234
 235     fn insert(&mut self, span: Span, hir_id: HirId, node: Node<'hir>) {
 236         self.insert_with_hash(span, hir_id, node, Fingerprint::ZERO)
 237     }
 238
 239     fn insert_with_hash(&mut self, span: Span, hir_id: HirId, node: Node<'hir>, hash: Fingerprint) {
 240         let entry = Entry { parent: self.parent_node, node };
 241
 242         // Make sure that the DepNode of some node coincides with the HirId
 243         // owner of that node.
 244         if cfg!(debug_assertions) {
 245             if hir_id.owner != self.current_dep_node_owner {
 246                 let node_str = match self.definitions.opt_hir_id_to_local_def_id(hir_id) {
 247                     Some(def_id) => self.definitions.def_path(def_id).to_string_no_crate_verbose(),
 248                     None => format!("{:?}", node),
 249                 };
 250
 251                 span_bug!(
 252                     span,
 253                     "inconsistent DepNode at `{:?}` for `{}`: \
 254                      current_dep_node_owner={} ({:?}), hir_id.owner={} ({:?})",
 255                     self.source_map.span_to_string(span),
 256                     node_str,
 257                     self.definitions
 258                         .def_path(self.current_dep_node_owner)
 259                         .to_string_no_crate_verbose(),
 260                     self.current_dep_node_owner,
 261                     self.definitions.def_path(hir_id.owner).to_string_no_crate_verbose(),
 262                     hir_id.owner,
 263                 )
 264             }
 265         }
 266
 267         self.insert_entry(hir_id, entry, hash);
 268     }
 269
 270     fn with_parent<F: FnOnce(&mut Self)>(&mut self, parent_node_id: HirId, f: F) {
 271         let parent_node = self.parent_node;
 272         self.parent_node = parent_node_id;
 273         f(self);
 274         self.parent_node = parent_node;
 275     }
 276
 277     fn with_dep_node_owner<
 278         T: for<'b> HashStable<StableHashingContext<'b>>,
 279         F: FnOnce(&mut Self, Fingerprint),
 280     >(
 281         &mut self,
 282         dep_node_owner: LocalDefId,
 283         item_like: &T,
 284         f: F,
 285     ) {
 286         let prev_owner = self.current_dep_node_owner;
 287
 288         let def_path_hash = self.definitions.def_path_hash(dep_node_owner);
 289
 290         let hash = hash_body(&mut self.hcx, def_path_hash, item_like, &mut self.hir_body_nodes);
 291
 292         self.current_dep_node_owner = dep_node_owner;
 293         f(self, hash);
 294         self.current_dep_node_owner = prev_owner;
 295     }
 296 }
 297
 298 impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
 299     type Map = Map<'hir>;
 300
 301     /// Because we want to track parent items and so forth, enable
 302     /// deep walking so that we walk nested items in the context of
 303     /// their outer items.
 304
 305     fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
 306         panic!("`visit_nested_xxx` must be manually implemented in this visitor");
 307     }
 308
 309     fn visit_nested_item(&mut self, item: ItemId) {
 310         debug!("visit_nested_item: {:?}", item);
 311         self.visit_item(self.krate.item(item.id));
 312     }
 313
 314     fn visit_nested_trait_item(&mut self, item_id: TraitItemId) {
 315         self.visit_trait_item(self.krate.trait_item(item_id));
 316     }
 317
 318     fn visit_nested_impl_item(&mut self, item_id: ImplItemId) {
 319         self.visit_impl_item(self.krate.impl_item(item_id));
 320     }
 321
 322     fn visit_nested_body(&mut self, id: BodyId) {
 323         self.visit_body(self.krate.body(id));
 324     }
 325
 326     fn visit_param(&mut self, param: &'hir Param<'hir>) {
 327         let node = Node::Param(param);
 328         self.insert(param.pat.span, param.hir_id, node);
 329         self.with_parent(param.hir_id, |this| {
 330             intravisit::walk_param(this, param);
 331         });
 332     }
 333
 334     fn visit_item(&mut self, i: &'hir Item<'hir>) {
 335         debug!("visit_item: {:?}", i);
 336         debug_assert_eq!(
 337             i.hir_id.owner,
 338             self.definitions.opt_hir_id_to_local_def_id(i.hir_id).unwrap()
 339         );
 340         self.with_dep_node_owner(i.hir_id.owner, i, |this, hash| {
 341             this.insert_with_hash(i.span, i.hir_id, Node::Item(i), hash);
 342             this.with_parent(i.hir_id, |this| {
 343                 if let ItemKind::Struct(ref struct_def, _) = i.kind {
 344                     // If this is a tuple or unit-like struct, register the constructor.
 345                     if let Some(ctor_hir_id) = struct_def.ctor_hir_id() {
 346                         this.insert(i.span, ctor_hir_id, Node::Ctor(struct_def));
 347                     }
 348                 }
 349                 intravisit::walk_item(this, i);
 350             });
 351         });
 352     }
 353
 354     fn visit_foreign_item(&mut self, foreign_item: &'hir ForeignItem<'hir>) {
 355         self.insert(foreign_item.span, foreign_item.hir_id, Node::ForeignItem(foreign_item));
 356
 357         self.with_parent(foreign_item.hir_id, |this| {
 358             intravisit::walk_foreign_item(this, foreign_item);
 359         });
 360     }
 361
 362     fn visit_generic_param(&mut self, param: &'hir GenericParam<'hir>) {
 363         self.insert(param.span, param.hir_id, Node::GenericParam(param));
 364         intravisit::walk_generic_param(self, param);
 365     }
 366
 367     fn visit_trait_item(&mut self, ti: &'hir TraitItem<'hir>) {
 368         debug_assert_eq!(
 369             ti.hir_id.owner,
 370             self.definitions.opt_hir_id_to_local_def_id(ti.hir_id).unwrap()
 371         );
 372         self.with_dep_node_owner(ti.hir_id.owner, ti, |this, hash| {
 373             this.insert_with_hash(ti.span, ti.hir_id, Node::TraitItem(ti), hash);
 374
 375             this.with_parent(ti.hir_id, |this| {
 376                 intravisit::walk_trait_item(this, ti);
 377             });
 378         });
 379     }
 380
 381     fn visit_impl_item(&mut self, ii: &'hir ImplItem<'hir>) {
 382         debug_assert_eq!(
 383             ii.hir_id.owner,
 384             self.definitions.opt_hir_id_to_local_def_id(ii.hir_id).unwrap()
 385         );
 386         self.with_dep_node_owner(ii.hir_id.owner, ii, |this, hash| {
 387             this.insert_with_hash(ii.span, ii.hir_id, Node::ImplItem(ii), hash);
 388
 389             this.with_parent(ii.hir_id, |this| {
 390                 intravisit::walk_impl_item(this, ii);
 391             });
 392         });
 393     }
 394
 395     fn visit_pat(&mut self, pat: &'hir Pat<'hir>) {
 396         let node =
 397             if let PatKind::Binding(..) = pat.kind { Node::Binding(pat) } else { Node::Pat(pat) };
 398         self.insert(pat.span, pat.hir_id, node);
 399
 400         self.with_parent(pat.hir_id, |this| {
 401             intravisit::walk_pat(this, pat);
 402         });
 403     }
 404
 405     fn visit_arm(&mut self, arm: &'hir Arm<'hir>) {
 406         let node = Node::Arm(arm);
 407
 408         self.insert(arm.span, arm.hir_id, node);
 409
 410         self.with_parent(arm.hir_id, |this| {
 411             intravisit::walk_arm(this, arm);
 412         });
 413     }
 414
 415     fn visit_anon_const(&mut self, constant: &'hir AnonConst) {
 416         self.insert(DUMMY_SP, constant.hir_id, Node::AnonConst(constant));
 417
 418         self.with_parent(constant.hir_id, |this| {
 419             intravisit::walk_anon_const(this, constant);
 420         });
 421     }
 422
 423     fn visit_expr(&mut self, expr: &'hir Expr<'hir>) {
 424         self.insert(expr.span, expr.hir_id, Node::Expr(expr));
 425
 426         self.with_parent(expr.hir_id, |this| {
 427             intravisit::walk_expr(this, expr);
 428         });
 429     }
 430
 431     fn visit_stmt(&mut self, stmt: &'hir Stmt<'hir>) {
 432         self.insert(stmt.span, stmt.hir_id, Node::Stmt(stmt));
 433
 434         self.with_parent(stmt.hir_id, |this| {
 435             intravisit::walk_stmt(this, stmt);
 436         });
 437     }
 438
 439     fn visit_path_segment(&mut self, path_span: Span, path_segment: &'hir PathSegment<'hir>) {
 440         if let Some(hir_id) = path_segment.hir_id {
 441             self.insert(path_span, hir_id, Node::PathSegment(path_segment));
 442         }
 443         intravisit::walk_path_segment(self, path_span, path_segment);
 444     }
 445
 446     fn visit_ty(&mut self, ty: &'hir Ty<'hir>) {
 447         self.insert(ty.span, ty.hir_id, Node::Ty(ty));
 448
 449         self.with_parent(ty.hir_id, |this| {
 450             intravisit::walk_ty(this, ty);
 451         });
 452     }
 453
 454     fn visit_trait_ref(&mut self, tr: &'hir TraitRef<'hir>) {
 455         self.insert(tr.path.span, tr.hir_ref_id, Node::TraitRef(tr));
 456
 457         self.with_parent(tr.hir_ref_id, |this| {
 458             intravisit::walk_trait_ref(this, tr);
 459         });
 460     }
 461
 462     fn visit_fn(
 463         &mut self,
 464         fk: intravisit::FnKind<'hir>,
 465         fd: &'hir FnDecl<'hir>,
 466         b: BodyId,
 467         s: Span,
 468         id: HirId,
 469     ) {
 470         assert_eq!(self.parent_node, id);
 471         intravisit::walk_fn(self, fk, fd, b, s, id);
 472     }
 473
 474     fn visit_block(&mut self, block: &'hir Block<'hir>) {
 475         self.insert(block.span, block.hir_id, Node::Block(block));
 476         self.with_parent(block.hir_id, |this| {
 477             intravisit::walk_block(this, block);
 478         });
 479     }
 480
 481     fn visit_local(&mut self, l: &'hir Local<'hir>) {
 482         self.insert(l.span, l.hir_id, Node::Local(l));
 483         self.with_parent(l.hir_id, |this| intravisit::walk_local(this, l))
 484     }
 485
 486     fn visit_lifetime(&mut self, lifetime: &'hir Lifetime) {
 487         self.insert(lifetime.span, lifetime.hir_id, Node::Lifetime(lifetime));
 488     }
 489
 490     fn visit_vis(&mut self, visibility: &'hir Visibility<'hir>) {
 491         match visibility.node {
 492             VisibilityKind::Public | VisibilityKind::Crate(_) | VisibilityKind::Inherited => {}
 493             VisibilityKind::Restricted { hir_id, .. } => {
 494                 self.insert(visibility.span, hir_id, Node::Visibility(visibility));
 495                 self.with_parent(hir_id, |this| {
 496                     intravisit::walk_vis(this, visibility);
 497                 });
 498             }
 499         }
 500     }
 501
 502     fn visit_macro_def(&mut self, macro_def: &'hir MacroDef<'hir>) {
 503         self.with_dep_node_owner(macro_def.hir_id.owner, macro_def, |this, hash| {
 504             this.insert_with_hash(
 505                 macro_def.span,
 506                 macro_def.hir_id,
 507                 Node::MacroDef(macro_def),
 508                 hash,
 509             );
 510         });
 511     }
 512
 513     fn visit_variant(&mut self, v: &'hir Variant<'hir>, g: &'hir Generics<'hir>, item_id: HirId) {
 514         self.insert(v.span, v.id, Node::Variant(v));
 515         self.with_parent(v.id, |this| {
 516             // Register the constructor of this variant.
 517             if let Some(ctor_hir_id) = v.data.ctor_hir_id() {
 518                 this.insert(v.span, ctor_hir_id, Node::Ctor(&v.data));
 519             }
 520             intravisit::walk_variant(this, v, g, item_id);
 521         });
 522     }
 523
 524     fn visit_struct_field(&mut self, field: &'hir StructField<'hir>) {
 525         self.insert(field.span, field.hir_id, Node::Field(field));
 526         self.with_parent(field.hir_id, |this| {
 527             intravisit::walk_struct_field(this, field);
 528         });
 529     }
 530
 531     fn visit_trait_item_ref(&mut self, ii: &'hir TraitItemRef) {
 532         // Do not visit the duplicate information in TraitItemRef. We want to
 533         // map the actual nodes, not the duplicate ones in the *Ref.
 534         let TraitItemRef { id, ident: _, kind: _, span: _, defaultness: _ } = *ii;
 535
 536         self.visit_nested_trait_item(id);
 537     }
 538
 539     fn visit_impl_item_ref(&mut self, ii: &'hir ImplItemRef<'hir>) {
 540         // Do not visit the duplicate information in ImplItemRef. We want to
 541         // map the actual nodes, not the duplicate ones in the *Ref.
 542         let ImplItemRef { id, ident: _, kind: _, span: _, vis: _, defaultness: _ } = *ii;
 543
 544         self.visit_nested_impl_item(id);
 545     }
 546 }
 547
 548 struct HirItemLike<T> {
 549     item_like: T,
 550 }
 551
 552 impl<'hir, T> HashStable<StableHashingContext<'hir>> for HirItemLike<T>
 553 where
 554     T: HashStable<StableHashingContext<'hir>>,
 555 {
 556     fn hash_stable(&self, hcx: &mut StableHashingContext<'hir>, hasher: &mut StableHasher) {
 557         hcx.while_hashing_hir_bodies(true, |hcx| {
 558             self.item_like.hash_stable(hcx, hasher);
 559         });
 560     }
 561 }