src/librustc/hir/map/collector.rs

   1 use super::*;
   2 use crate::dep_graph::{DepGraph, DepKind, DepNodeIndex};
   3 use crate::hir;
   4 use crate::hir::def_id::{LOCAL_CRATE, CrateNum};
   5 use crate::hir::intravisit::{Visitor, NestedVisitorMap};
   6 use rustc_data_structures::svh::Svh;
   7 use crate::ich::Fingerprint;
   8 use crate::middle::cstore::CrateStore;
   9 use crate::session::CrateDisambiguator;
  10 use crate::session::Session;
  11 use std::iter::repeat;
  12 use syntax::ast::{NodeId, CRATE_NODE_ID};
  13 use syntax::source_map::SourceMap;
  14 use syntax_pos::Span;
  15
  16 use crate::ich::StableHashingContext;
  17 use rustc_data_structures::stable_hasher::{HashStable, StableHasher, StableHasherResult};
  18
  19 /// A Visitor that walks over the HIR and collects Nodes into a HIR map
  20 pub(super) struct NodeCollector<'a, 'hir> {
  21     /// The crate
  22     krate: &'hir Crate,
  23
  24     /// Source map
  25     source_map: &'a SourceMap,
  26
  27     /// The node map
  28     map: Vec<Option<Entry<'hir>>>,
  29     /// The parent of this node
  30     parent_node: hir::HirId,
  31
  32     // These fields keep track of the currently relevant DepNodes during
  33     // the visitor's traversal.
  34     current_dep_node_owner: DefIndex,
  35     current_signature_dep_index: DepNodeIndex,
  36     current_full_dep_index: DepNodeIndex,
  37     currently_in_body: bool,
  38
  39     dep_graph: &'a DepGraph,
  40     definitions: &'a definitions::Definitions,
  41     hir_to_node_id: &'a FxHashMap<HirId, NodeId>,
  42
  43     hcx: StableHashingContext<'a>,
  44
  45     // We are collecting DepNode::HirBody hashes here so we can compute the
  46     // crate hash from then later on.
  47     hir_body_nodes: Vec<(DefPathHash, Fingerprint)>,
  48 }
  49
  50 fn input_dep_node_and_hash<I>(
  51     dep_graph: &DepGraph,
  52     hcx: &mut StableHashingContext<'_>,
  53     dep_node: DepNode,
  54     input: I,
  55 ) -> (DepNodeIndex, Fingerprint)
  56 where
  57     I: for<'a> HashStable<StableHashingContext<'a>>,
  58 {
  59     let dep_node_index = dep_graph.input_task(dep_node, &mut *hcx, &input).1;
  60
  61     let hash = if dep_graph.is_fully_enabled() {
  62         dep_graph.fingerprint_of(dep_node_index)
  63     } else {
  64         let mut stable_hasher = StableHasher::new();
  65         input.hash_stable(hcx, &mut stable_hasher);
  66         stable_hasher.finish()
  67     };
  68
  69     (dep_node_index, hash)
  70 }
  71
  72 fn alloc_hir_dep_nodes<I>(
  73     dep_graph: &DepGraph,
  74     hcx: &mut StableHashingContext<'_>,
  75     def_path_hash: DefPathHash,
  76     item_like: I,
  77     hir_body_nodes: &mut Vec<(DefPathHash, Fingerprint)>,
  78 ) -> (DepNodeIndex, DepNodeIndex)
  79 where
  80     I: for<'a> HashStable<StableHashingContext<'a>>,
  81 {
  82     let sig = dep_graph.input_task(
  83         def_path_hash.to_dep_node(DepKind::Hir),
  84         &mut *hcx,
  85         HirItemLike { item_like: &item_like, hash_bodies: false },
  86     ).1;
  87     let (full, hash) = input_dep_node_and_hash(
  88         dep_graph,
  89         hcx,
  90         def_path_hash.to_dep_node(DepKind::HirBody),
  91         HirItemLike { item_like: &item_like, hash_bodies: true },
  92     );
  93     hir_body_nodes.push((def_path_hash, hash));
  94     (sig, full)
  95 }
  96
  97 impl<'a, 'hir> NodeCollector<'a, 'hir> {
  98     pub(super) fn root(sess: &'a Session,
  99                        krate: &'hir Crate,
 100                        dep_graph: &'a DepGraph,
 101                        definitions: &'a definitions::Definitions,
 102                        hir_to_node_id: &'a FxHashMap<HirId, NodeId>,
 103                        mut hcx: StableHashingContext<'a>)
 104                 -> NodeCollector<'a, 'hir> {
 105         let root_mod_def_path_hash = definitions.def_path_hash(CRATE_DEF_INDEX);
 106
 107         let mut hir_body_nodes = Vec::new();
 108
 109         // Allocate DepNodes for the root module
 110         let (root_mod_sig_dep_index, root_mod_full_dep_index) = {
 111             let Crate {
 112                 ref module,
 113                 // Crate attributes are not copied over to the root `Mod`, so hash
 114                 // them explicitly here.
 115                 ref attrs,
 116                 span,
 117                 // These fields are handled separately:
 118                 exported_macros: _,
 119                 items: _,
 120                 trait_items: _,
 121                 impl_items: _,
 122                 bodies: _,
 123                 trait_impls: _,
 124                 trait_auto_impl: _,
 125                 body_ids: _,
 126                 modules: _,
 127             } = *krate;
 128
 129             alloc_hir_dep_nodes(
 130                 dep_graph,
 131                 &mut hcx,
 132                 root_mod_def_path_hash,
 133                 (module, attrs, span),
 134                 &mut hir_body_nodes,
 135             )
 136         };
 137
 138         {
 139             dep_graph.input_task(
 140                 DepNode::new_no_params(DepKind::AllLocalTraitImpls),
 141                 &mut hcx,
 142                 &krate.trait_impls,
 143             );
 144         }
 145
 146         let mut collector = NodeCollector {
 147             krate,
 148             source_map: sess.source_map(),
 149             map: repeat(None).take(sess.current_node_id_count()).collect(),
 150             parent_node: hir::CRATE_HIR_ID,
 151             current_signature_dep_index: root_mod_sig_dep_index,
 152             current_full_dep_index: root_mod_full_dep_index,
 153             current_dep_node_owner: CRATE_DEF_INDEX,
 154             currently_in_body: false,
 155             dep_graph,
 156             definitions,
 157             hir_to_node_id,
 158             hcx,
 159             hir_body_nodes,
 160         };
 161         collector.insert_entry(CRATE_NODE_ID, Entry {
 162             parent: CRATE_NODE_ID,
 163             parent_hir: hir::CRATE_HIR_ID,
 164             dep_node: root_mod_sig_dep_index,
 165             node: Node::Crate,
 166         });
 167
 168         collector
 169     }
 170
 171     pub(super) fn finalize_and_compute_crate_hash(mut self,
 172                                                   crate_disambiguator: CrateDisambiguator,
 173                                                   cstore: &dyn CrateStore,
 174                                                   commandline_args_hash: u64)
 175                                                   -> (Vec<Option<Entry<'hir>>>, Svh)
 176     {
 177         self.hir_body_nodes.sort_unstable_by_key(|bn| bn.0);
 178
 179         let node_hashes = self
 180             .hir_body_nodes
 181             .iter()
 182             .fold(Fingerprint::ZERO, |combined_fingerprint, &(def_path_hash, fingerprint)| {
 183                 combined_fingerprint.combine(def_path_hash.0.combine(fingerprint))
 184             });
 185
 186         let mut upstream_crates: Vec<_> = cstore.crates_untracked().iter().map(|&cnum| {
 187             let name = cstore.crate_name_untracked(cnum).as_str();
 188             let disambiguator = cstore.crate_disambiguator_untracked(cnum).to_fingerprint();
 189             let hash = cstore.crate_hash_untracked(cnum);
 190             (name, disambiguator, hash)
 191         }).collect();
 192
 193         upstream_crates.sort_unstable_by_key(|&(name, dis, _)| (name, dis));
 194
 195         // We hash the final, remapped names of all local source files so we
 196         // don't have to include the path prefix remapping commandline args.
 197         // If we included the full mapping in the SVH, we could only have
 198         // reproducible builds by compiling from the same directory. So we just
 199         // hash the result of the mapping instead of the mapping itself.
 200         let mut source_file_names: Vec<_> = self
 201             .source_map
 202             .files()
 203             .iter()
 204             .filter(|source_file| CrateNum::from_u32(source_file.crate_of_origin) == LOCAL_CRATE)
 205             .map(|source_file| source_file.name_hash)
 206             .collect();
 207
 208         source_file_names.sort_unstable();
 209
 210         let crate_hash_input = (
 211             ((node_hashes, upstream_crates), source_file_names),
 212             (commandline_args_hash, crate_disambiguator.to_fingerprint())
 213         );
 214
 215         let (_, crate_hash) = input_dep_node_and_hash(
 216             self.dep_graph,
 217             &mut self.hcx,
 218             DepNode::new_no_params(DepKind::Krate),
 219             crate_hash_input,
 220         );
 221
 222         let svh = Svh::new(crate_hash.to_smaller_hash());
 223         (self.map, svh)
 224     }
 225
 226     fn insert_entry(&mut self, id: NodeId, entry: Entry<'hir>) {
 227         debug!("hir_map: {:?} => {:?}", id, entry);
 228         self.map[id.as_usize()] = Some(entry);
 229     }
 230
 231     fn insert(&mut self, span: Span, hir_id: HirId, node: Node<'hir>) {
 232         let entry = Entry {
 233             parent: self.hir_to_node_id[&self.parent_node],
 234             parent_hir: self.parent_node,
 235             dep_node: if self.currently_in_body {
 236                 self.current_full_dep_index
 237             } else {
 238                 self.current_signature_dep_index
 239             },
 240             node,
 241         };
 242
 243         let node_id = self.hir_to_node_id[&hir_id];
 244
 245         // Make sure that the DepNode of some node coincides with the HirId
 246         // owner of that node.
 247         if cfg!(debug_assertions) {
 248            assert_eq!(self.definitions.node_to_hir_id(node_id), hir_id);
 249
 250             if hir_id.owner != self.current_dep_node_owner {
 251                 let node_str = match self.definitions.opt_def_index(node_id) {
 252                     Some(def_index) => {
 253                         self.definitions.def_path(def_index).to_string_no_crate()
 254                     }
 255                     None => format!("{:?}", node)
 256                 };
 257
 258                 let forgot_str = if hir_id == crate::hir::DUMMY_HIR_ID {
 259                     format!("\nMaybe you forgot to lower the node id {:?}?", node_id)
 260                 } else {
 261                     String::new()
 262                 };
 263
 264                 span_bug!(
 265                     span,
 266                     "inconsistent DepNode at `{:?}` for `{}`: \
 267                      current_dep_node_owner={} ({:?}), hir_id.owner={} ({:?}){}",
 268                     self.source_map.span_to_string(span),
 269                     node_str,
 270                     self.definitions
 271                         .def_path(self.current_dep_node_owner)
 272                         .to_string_no_crate(),
 273                     self.current_dep_node_owner,
 274                     self.definitions.def_path(hir_id.owner).to_string_no_crate(),
 275                     hir_id.owner,
 276                     forgot_str,
 277                 )
 278             }
 279         }
 280
 281         self.insert_entry(node_id, entry);
 282     }
 283
 284     fn with_parent<F: FnOnce(&mut Self)>(
 285         &mut self,
 286         parent_node_id: HirId,
 287         f: F,
 288     ) {
 289         let parent_node = self.parent_node;
 290         self.parent_node = parent_node_id;
 291         f(self);
 292         self.parent_node = parent_node;
 293     }
 294
 295     fn with_dep_node_owner<T: for<'b> HashStable<StableHashingContext<'b>>,
 296                            F: FnOnce(&mut Self)>(&mut self,
 297                                                  dep_node_owner: DefIndex,
 298                                                  item_like: &T,
 299                                                  f: F) {
 300         let prev_owner = self.current_dep_node_owner;
 301         let prev_signature_dep_index = self.current_signature_dep_index;
 302         let prev_full_dep_index = self.current_full_dep_index;
 303         let prev_in_body = self.currently_in_body;
 304
 305         let def_path_hash = self.definitions.def_path_hash(dep_node_owner);
 306
 307         let (signature_dep_index, full_dep_index) = alloc_hir_dep_nodes(
 308             self.dep_graph,
 309             &mut self.hcx,
 310             def_path_hash,
 311             item_like,
 312             &mut self.hir_body_nodes,
 313         );
 314         self.current_signature_dep_index = signature_dep_index;
 315         self.current_full_dep_index = full_dep_index;
 316
 317         self.current_dep_node_owner = dep_node_owner;
 318         self.currently_in_body = false;
 319         f(self);
 320         self.currently_in_body = prev_in_body;
 321         self.current_dep_node_owner = prev_owner;
 322         self.current_full_dep_index = prev_full_dep_index;
 323         self.current_signature_dep_index = prev_signature_dep_index;
 324     }
 325 }
 326
 327 impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
 328     /// Because we want to track parent items and so forth, enable
 329     /// deep walking so that we walk nested items in the context of
 330     /// their outer items.
 331
 332     fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'hir> {
 333         panic!("visit_nested_xxx must be manually implemented in this visitor")
 334     }
 335
 336     fn visit_nested_item(&mut self, item: ItemId) {
 337         debug!("visit_nested_item: {:?}", item);
 338         self.visit_item(self.krate.item(item.id));
 339     }
 340
 341     fn visit_nested_trait_item(&mut self, item_id: TraitItemId) {
 342         self.visit_trait_item(self.krate.trait_item(item_id));
 343     }
 344
 345     fn visit_nested_impl_item(&mut self, item_id: ImplItemId) {
 346         self.visit_impl_item(self.krate.impl_item(item_id));
 347     }
 348
 349     fn visit_nested_body(&mut self, id: BodyId) {
 350         let prev_in_body = self.currently_in_body;
 351         self.currently_in_body = true;
 352         self.visit_body(self.krate.body(id));
 353         self.currently_in_body = prev_in_body;
 354     }
 355
 356     fn visit_item(&mut self, i: &'hir Item) {
 357         debug!("visit_item: {:?}", i);
 358         debug_assert_eq!(i.hir_id.owner,
 359                          self.definitions.opt_def_index(i.id).unwrap());
 360         self.with_dep_node_owner(i.hir_id.owner, i, |this| {
 361             this.insert(i.span, i.hir_id, Node::Item(i));
 362             this.with_parent(i.hir_id, |this| {
 363                 if let ItemKind::Struct(ref struct_def, _) = i.node {
 364                     // If this is a tuple-like struct, register the constructor.
 365                     if !struct_def.is_struct() {
 366                         this.insert(i.span, struct_def.hir_id(), Node::StructCtor(struct_def));
 367                     }
 368                 }
 369                 intravisit::walk_item(this, i);
 370             });
 371         });
 372     }
 373
 374     fn visit_foreign_item(&mut self, foreign_item: &'hir ForeignItem) {
 375         self.insert(foreign_item.span, foreign_item.hir_id, Node::ForeignItem(foreign_item));
 376
 377         self.with_parent(foreign_item.hir_id, |this| {
 378             intravisit::walk_foreign_item(this, foreign_item);
 379         });
 380     }
 381
 382     fn visit_generic_param(&mut self, param: &'hir GenericParam) {
 383         self.insert(param.span, param.hir_id, Node::GenericParam(param));
 384         intravisit::walk_generic_param(self, param);
 385     }
 386
 387     fn visit_trait_item(&mut self, ti: &'hir TraitItem) {
 388         debug_assert_eq!(ti.hir_id.owner,
 389                          self.definitions.opt_def_index(ti.id).unwrap());
 390         self.with_dep_node_owner(ti.hir_id.owner, ti, |this| {
 391             this.insert(ti.span, ti.hir_id, Node::TraitItem(ti));
 392
 393             this.with_parent(ti.hir_id, |this| {
 394                 intravisit::walk_trait_item(this, ti);
 395             });
 396         });
 397     }
 398
 399     fn visit_impl_item(&mut self, ii: &'hir ImplItem) {
 400         debug_assert_eq!(ii.hir_id.owner,
 401                          self.definitions.opt_def_index(ii.id).unwrap());
 402         self.with_dep_node_owner(ii.hir_id.owner, ii, |this| {
 403             this.insert(ii.span, ii.hir_id, Node::ImplItem(ii));
 404
 405             this.with_parent(ii.hir_id, |this| {
 406                 intravisit::walk_impl_item(this, ii);
 407             });
 408         });
 409     }
 410
 411     fn visit_pat(&mut self, pat: &'hir Pat) {
 412         let node = if let PatKind::Binding(..) = pat.node {
 413             Node::Binding(pat)
 414         } else {
 415             Node::Pat(pat)
 416         };
 417         self.insert(pat.span, pat.hir_id, node);
 418
 419         self.with_parent(pat.hir_id, |this| {
 420             intravisit::walk_pat(this, pat);
 421         });
 422     }
 423
 424     fn visit_anon_const(&mut self, constant: &'hir AnonConst) {
 425         self.insert(DUMMY_SP, constant.hir_id, Node::AnonConst(constant));
 426
 427         self.with_parent(constant.hir_id, |this| {
 428             intravisit::walk_anon_const(this, constant);
 429         });
 430     }
 431
 432     fn visit_expr(&mut self, expr: &'hir Expr) {
 433         self.insert(expr.span, expr.hir_id, Node::Expr(expr));
 434
 435         self.with_parent(expr.hir_id, |this| {
 436             intravisit::walk_expr(this, expr);
 437         });
 438     }
 439
 440     fn visit_stmt(&mut self, stmt: &'hir Stmt) {
 441         self.insert(stmt.span, stmt.hir_id, Node::Stmt(stmt));
 442
 443         self.with_parent(stmt.hir_id, |this| {
 444             intravisit::walk_stmt(this, stmt);
 445         });
 446     }
 447
 448     fn visit_path_segment(&mut self, path_span: Span, path_segment: &'hir PathSegment) {
 449         if let Some(hir_id) = path_segment.hir_id {
 450             self.insert(path_span, hir_id, Node::PathSegment(path_segment));
 451         }
 452         intravisit::walk_path_segment(self, path_span, path_segment);
 453     }
 454
 455     fn visit_ty(&mut self, ty: &'hir Ty) {
 456         self.insert(ty.span, ty.hir_id, Node::Ty(ty));
 457
 458         self.with_parent(ty.hir_id, |this| {
 459             intravisit::walk_ty(this, ty);
 460         });
 461     }
 462
 463     fn visit_trait_ref(&mut self, tr: &'hir TraitRef) {
 464         self.insert(tr.path.span, tr.hir_ref_id, Node::TraitRef(tr));
 465
 466         self.with_parent(tr.hir_ref_id, |this| {
 467             intravisit::walk_trait_ref(this, tr);
 468         });
 469     }
 470
 471     fn visit_fn(&mut self, fk: intravisit::FnKind<'hir>, fd: &'hir FnDecl,
 472                 b: BodyId, s: Span, id: HirId) {
 473         assert_eq!(self.parent_node, id);
 474         intravisit::walk_fn(self, fk, fd, b, s, id);
 475     }
 476
 477     fn visit_block(&mut self, block: &'hir Block) {
 478         self.insert(block.span, block.hir_id, Node::Block(block));
 479         self.with_parent(block.hir_id, |this| {
 480             intravisit::walk_block(this, block);
 481         });
 482     }
 483
 484     fn visit_local(&mut self, l: &'hir Local) {
 485         self.insert(l.span, l.hir_id, Node::Local(l));
 486         self.with_parent(l.hir_id, |this| {
 487             intravisit::walk_local(this, l)
 488         })
 489     }
 490
 491     fn visit_lifetime(&mut self, lifetime: &'hir Lifetime) {
 492         self.insert(lifetime.span, lifetime.hir_id, Node::Lifetime(lifetime));
 493     }
 494
 495     fn visit_vis(&mut self, visibility: &'hir Visibility) {
 496         match visibility.node {
 497             VisibilityKind::Public |
 498             VisibilityKind::Crate(_) |
 499             VisibilityKind::Inherited => {}
 500             VisibilityKind::Restricted { hir_id, .. } => {
 501                 self.insert(visibility.span, hir_id, Node::Visibility(visibility));
 502                 self.with_parent(hir_id, |this| {
 503                     intravisit::walk_vis(this, visibility);
 504                 });
 505             }
 506         }
 507     }
 508
 509     fn visit_macro_def(&mut self, macro_def: &'hir MacroDef) {
 510         let def_index = self.definitions.opt_def_index(macro_def.id).unwrap();
 511
 512         self.with_dep_node_owner(def_index, macro_def, |this| {
 513             this.insert(macro_def.span, macro_def.hir_id, Node::MacroDef(macro_def));
 514         });
 515     }
 516
 517     fn visit_variant(&mut self, v: &'hir Variant, g: &'hir Generics, item_id: HirId) {
 518         self.insert(v.span, v.node.data.hir_id(), Node::Variant(v));
 519         self.with_parent(v.node.data.hir_id(), |this| {
 520             intravisit::walk_variant(this, v, g, item_id);
 521         });
 522     }
 523
 524     fn visit_struct_field(&mut self, field: &'hir StructField) {
 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 {
 535             id,
 536             ident: _,
 537             kind: _,
 538             span: _,
 539             defaultness: _,
 540         } = *ii;
 541
 542         self.visit_nested_trait_item(id);
 543     }
 544
 545     fn visit_impl_item_ref(&mut self, ii: &'hir ImplItemRef) {
 546         // Do not visit the duplicate information in ImplItemRef. We want to
 547         // map the actual nodes, not the duplicate ones in the *Ref.
 548         let ImplItemRef {
 549             id,
 550             ident: _,
 551             kind: _,
 552             span: _,
 553             vis: _,
 554             defaultness: _,
 555         } = *ii;
 556
 557         self.visit_nested_impl_item(id);
 558     }
 559 }
 560
 561 // This is a wrapper structure that allows determining if span values within
 562 // the wrapped item should be hashed or not.
 563 struct HirItemLike<T> {
 564     item_like: T,
 565     hash_bodies: bool,
 566 }
 567
 568 impl<'a, 'hir, T> HashStable<StableHashingContext<'hir>> for HirItemLike<T>
 569     where T: HashStable<StableHashingContext<'hir>>
 570 {
 571     fn hash_stable<W: StableHasherResult>(&self,
 572                                           hcx: &mut StableHashingContext<'hir>,
 573                                           hasher: &mut StableHasher<W>) {
 574         hcx.while_hashing_hir_bodies(self.hash_bodies, |hcx| {
 575             self.item_like.hash_stable(hcx, hasher);
 576         });
 577     }
 578 }