crates/ide_db/src/search.rs

   1 //! Implementation of find-usages functionality.
   2 //!
   3 //! It is based on the standard ide trick: first, we run a fast text search to
   4 //! get a super-set of matches. Then, we we confirm each match using precise
   5 //! name resolution.
   6
   7 use std::{convert::TryInto, mem, sync::Arc};
   8
   9 use base_db::{FileId, FileRange, SourceDatabase, SourceDatabaseExt};
  10 use hir::{
  11     AsAssocItem, DefWithBody, HasAttrs, HasSource, InFile, ModuleSource, Semantics, Visibility,
  12 };
  13 use once_cell::unsync::Lazy;
  14 use rustc_hash::FxHashMap;
  15 use syntax::{ast, match_ast, AstNode, TextRange, TextSize};
  16
  17 use crate::{
  18     defs::{Definition, NameClass, NameRefClass},
  19     RootDatabase,
  20 };
  21
  22 #[derive(Debug, Default, Clone)]
  23 pub struct UsageSearchResult {
  24     pub references: FxHashMap<FileId, Vec<FileReference>>,
  25 }
  26
  27 impl UsageSearchResult {
  28     pub fn is_empty(&self) -> bool {
  29         self.references.is_empty()
  30     }
  31
  32     pub fn len(&self) -> usize {
  33         self.references.len()
  34     }
  35
  36     pub fn iter(&self) -> impl Iterator<Item = (&FileId, &[FileReference])> + '_ {
  37         self.references.iter().map(|(file_id, refs)| (file_id, &**refs))
  38     }
  39
  40     pub fn file_ranges(&self) -> impl Iterator<Item = FileRange> + '_ {
  41         self.references.iter().flat_map(|(&file_id, refs)| {
  42             refs.iter().map(move |&FileReference { range, .. }| FileRange { file_id, range })
  43         })
  44     }
  45 }
  46
  47 impl IntoIterator for UsageSearchResult {
  48     type Item = (FileId, Vec<FileReference>);
  49     type IntoIter = <FxHashMap<FileId, Vec<FileReference>> as IntoIterator>::IntoIter;
  50
  51     fn into_iter(self) -> Self::IntoIter {
  52         self.references.into_iter()
  53     }
  54 }
  55
  56 #[derive(Debug, Clone)]
  57 pub struct FileReference {
  58     pub range: TextRange,
  59     pub name: ast::NameLike,
  60     pub category: Option<ReferenceCategory>,
  61 }
  62
  63 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
  64 pub enum ReferenceCategory {
  65     // FIXME: Add this variant and delete the `retain_adt_literal_usages` function.
  66     // Create
  67     Write,
  68     Read,
  69     // FIXME: Some day should be able to search in doc comments. Would probably
  70     // need to switch from enum to bitflags then?
  71     // DocComment
  72 }
  73
  74 /// Generally, `search_scope` returns files that might contain references for the element.
  75 /// For `pub(crate)` things it's a crate, for `pub` things it's a crate and dependant crates.
  76 /// In some cases, the location of the references is known to within a `TextRange`,
  77 /// e.g. for things like local variables.
  78 #[derive(Clone, Debug)]
  79 pub struct SearchScope {
  80     entries: FxHashMap<FileId, Option<TextRange>>,
  81 }
  82
  83 impl SearchScope {
  84     fn new(entries: FxHashMap<FileId, Option<TextRange>>) -> SearchScope {
  85         SearchScope { entries }
  86     }
  87
  88     fn crate_graph(db: &RootDatabase) -> SearchScope {
  89         let mut entries = FxHashMap::default();
  90
  91         let graph = db.crate_graph();
  92         for krate in graph.iter() {
  93             let root_file = graph[krate].root_file_id;
  94             let source_root_id = db.file_source_root(root_file);
  95             let source_root = db.source_root(source_root_id);
  96             entries.extend(source_root.iter().map(|id| (id, None)));
  97         }
  98         SearchScope { entries }
  99     }
 100
 101     fn reverse_dependencies(db: &RootDatabase, of: hir::Crate) -> SearchScope {
 102         let mut entries = FxHashMap::default();
 103         for rev_dep in of.transitive_reverse_dependencies(db) {
 104             let root_file = rev_dep.root_file(db);
 105             let source_root_id = db.file_source_root(root_file);
 106             let source_root = db.source_root(source_root_id);
 107             entries.extend(source_root.iter().map(|id| (id, None)));
 108         }
 109         SearchScope { entries }
 110     }
 111
 112     fn krate(db: &RootDatabase, of: hir::Crate) -> SearchScope {
 113         let root_file = of.root_file(db);
 114         let source_root_id = db.file_source_root(root_file);
 115         let source_root = db.source_root(source_root_id);
 116         SearchScope {
 117             entries: source_root.iter().map(|id| (id, None)).collect::<FxHashMap<_, _>>(),
 118         }
 119     }
 120
 121     fn module(db: &RootDatabase, module: hir::Module) -> SearchScope {
 122         let mut entries = FxHashMap::default();
 123
 124         let mut to_visit = vec![module];
 125         let mut is_first = true;
 126         while let Some(module) = to_visit.pop() {
 127             let src = module.definition_source(db);
 128             let file_id = src.file_id.original_file(db);
 129             match src.value {
 130                 ModuleSource::Module(m) => {
 131                     if is_first {
 132                         let range = Some(m.syntax().text_range());
 133                         entries.insert(file_id, range);
 134                     } else {
 135                         // We have already added the enclosing file to the search scope,
 136                         // so do nothing.
 137                     }
 138                 }
 139                 ModuleSource::BlockExpr(b) => {
 140                     if is_first {
 141                         let range = Some(b.syntax().text_range());
 142                         entries.insert(file_id, range);
 143                     } else {
 144                         // We have already added the enclosing file to the search scope,
 145                         // so do nothing.
 146                     }
 147                 }
 148                 ModuleSource::SourceFile(_) => {
 149                     entries.insert(file_id, None);
 150                 }
 151             };
 152             is_first = false;
 153             to_visit.extend(module.children(db));
 154         }
 155         SearchScope { entries }
 156     }
 157
 158     pub fn empty() -> SearchScope {
 159         SearchScope::new(FxHashMap::default())
 160     }
 161
 162     pub fn single_file(file: FileId) -> SearchScope {
 163         SearchScope::new(std::iter::once((file, None)).collect())
 164     }
 165
 166     pub fn file_range(range: FileRange) -> SearchScope {
 167         SearchScope::new(std::iter::once((range.file_id, Some(range.range))).collect())
 168     }
 169
 170     pub fn files(files: &[FileId]) -> SearchScope {
 171         SearchScope::new(files.iter().map(|f| (*f, None)).collect())
 172     }
 173
 174     pub fn intersection(&self, other: &SearchScope) -> SearchScope {
 175         let (mut small, mut large) = (&self.entries, &other.entries);
 176         if small.len() > large.len() {
 177             mem::swap(&mut small, &mut large)
 178         }
 179
 180         let res = small
 181             .iter()
 182             .filter_map(|(file_id, r1)| {
 183                 let r2 = large.get(file_id)?;
 184                 let r = intersect_ranges(*r1, *r2)?;
 185                 Some((*file_id, r))
 186             })
 187             .collect();
 188
 189         return SearchScope::new(res);
 190
 191         fn intersect_ranges(
 192             r1: Option<TextRange>,
 193             r2: Option<TextRange>,
 194         ) -> Option<Option<TextRange>> {
 195             match (r1, r2) {
 196                 (None, r) | (r, None) => Some(r),
 197                 (Some(r1), Some(r2)) => {
 198                     let r = r1.intersect(r2)?;
 199                     Some(Some(r))
 200                 }
 201             }
 202         }
 203     }
 204 }
 205
 206 impl IntoIterator for SearchScope {
 207     type Item = (FileId, Option<TextRange>);
 208     type IntoIter = std::collections::hash_map::IntoIter<FileId, Option<TextRange>>;
 209
 210     fn into_iter(self) -> Self::IntoIter {
 211         self.entries.into_iter()
 212     }
 213 }
 214
 215 impl Definition {
 216     fn search_scope(&self, db: &RootDatabase) -> SearchScope {
 217         let _p = profile::span("search_scope");
 218
 219         if let Definition::BuiltinType(_) = self {
 220             return SearchScope::crate_graph(db);
 221         }
 222
 223         // def is crate root
 224         // FIXME: We don't do searches for crates currently, as a crate does not actually have a single name
 225         if let &Definition::Module(module) = self {
 226             if module.is_crate_root(db) {
 227                 return SearchScope::reverse_dependencies(db, module.krate());
 228             }
 229         }
 230
 231         let module = match self.module(db) {
 232             Some(it) => it,
 233             None => return SearchScope::empty(),
 234         };
 235         let InFile { file_id, value: module_source } = module.definition_source(db);
 236         let file_id = file_id.original_file(db);
 237
 238         if let Definition::Local(var) = self {
 239             let def = match var.parent(db) {
 240                 DefWithBody::Function(f) => f.source(db).map(|src| src.syntax().cloned()),
 241                 DefWithBody::Const(c) => c.source(db).map(|src| src.syntax().cloned()),
 242                 DefWithBody::Static(s) => s.source(db).map(|src| src.syntax().cloned()),
 243             };
 244             return match def {
 245                 Some(def) => SearchScope::file_range(def.as_ref().original_file_range(db)),
 246                 None => SearchScope::single_file(file_id),
 247             };
 248         }
 249
 250         if let Definition::SelfType(impl_) = self {
 251             return match impl_.source(db).map(|src| src.syntax().cloned()) {
 252                 Some(def) => SearchScope::file_range(def.as_ref().original_file_range(db)),
 253                 None => SearchScope::single_file(file_id),
 254             };
 255         }
 256
 257         if let Definition::GenericParam(hir::GenericParam::LifetimeParam(param)) = self {
 258             let def = match param.parent(db) {
 259                 hir::GenericDef::Function(it) => it.source(db).map(|src| src.syntax().cloned()),
 260                 hir::GenericDef::Adt(it) => it.source(db).map(|src| src.syntax().cloned()),
 261                 hir::GenericDef::Trait(it) => it.source(db).map(|src| src.syntax().cloned()),
 262                 hir::GenericDef::TypeAlias(it) => it.source(db).map(|src| src.syntax().cloned()),
 263                 hir::GenericDef::Impl(it) => it.source(db).map(|src| src.syntax().cloned()),
 264                 hir::GenericDef::Variant(it) => it.source(db).map(|src| src.syntax().cloned()),
 265                 hir::GenericDef::Const(it) => it.source(db).map(|src| src.syntax().cloned()),
 266             };
 267             return match def {
 268                 Some(def) => SearchScope::file_range(def.as_ref().original_file_range(db)),
 269                 None => SearchScope::single_file(file_id),
 270             };
 271         }
 272
 273         if let Definition::Macro(macro_def) = self {
 274             return match macro_def.kind(db) {
 275                 hir::MacroKind::Declarative => {
 276                     if macro_def.attrs(db).by_key("macro_export").exists() {
 277                         SearchScope::reverse_dependencies(db, module.krate())
 278                     } else {
 279                         SearchScope::krate(db, module.krate())
 280                     }
 281                 }
 282                 hir::MacroKind::BuiltIn => SearchScope::crate_graph(db),
 283                 // FIXME: We don't actually see derives in derive attributes as these do not
 284                 // expand to something that references the derive macro in the output.
 285                 // We could get around this by emitting dummy `use DeriveMacroPathHere as _;` items maybe?
 286                 hir::MacroKind::Derive | hir::MacroKind::Attr | hir::MacroKind::ProcMacro => {
 287                     SearchScope::reverse_dependencies(db, module.krate())
 288                 }
 289             };
 290         }
 291
 292         let vis = self.visibility(db);
 293         if let Some(Visibility::Public) = vis {
 294             return SearchScope::reverse_dependencies(db, module.krate());
 295         }
 296         if let Some(Visibility::Module(module)) = vis {
 297             return SearchScope::module(db, module.into());
 298         }
 299
 300         let range = match module_source {
 301             ModuleSource::Module(m) => Some(m.syntax().text_range()),
 302             ModuleSource::BlockExpr(b) => Some(b.syntax().text_range()),
 303             ModuleSource::SourceFile(_) => None,
 304         };
 305         match range {
 306             Some(range) => SearchScope::file_range(FileRange { file_id, range }),
 307             None => SearchScope::single_file(file_id),
 308         }
 309     }
 310
 311     pub fn usages<'a>(self, sema: &'a Semantics<RootDatabase>) -> FindUsages<'a> {
 312         FindUsages {
 313             local_repr: match self {
 314                 Definition::Local(local) => Some(local.representative(sema.db)),
 315                 _ => None,
 316             },
 317             def: self,
 318             sema,
 319             scope: None,
 320             include_self_kw_refs: None,
 321             search_self_mod: false,
 322         }
 323     }
 324 }
 325
 326 #[derive(Clone)]
 327 pub struct FindUsages<'a> {
 328     def: Definition,
 329     sema: &'a Semantics<'a, RootDatabase>,
 330     scope: Option<SearchScope>,
 331     include_self_kw_refs: Option<hir::Type>,
 332     local_repr: Option<hir::Local>,
 333     search_self_mod: bool,
 334 }
 335
 336 impl<'a> FindUsages<'a> {
 337     /// Enable searching for `Self` when the definition is a type or `self` for modules.
 338     pub fn include_self_refs(mut self) -> FindUsages<'a> {
 339         self.include_self_kw_refs = def_to_ty(self.sema, &self.def);
 340         self.search_self_mod = true;
 341         self
 342     }
 343
 344     pub fn in_scope(self, scope: SearchScope) -> FindUsages<'a> {
 345         self.set_scope(Some(scope))
 346     }
 347
 348     pub fn set_scope(mut self, scope: Option<SearchScope>) -> FindUsages<'a> {
 349         assert!(self.scope.is_none());
 350         self.scope = scope;
 351         self
 352     }
 353
 354     pub fn at_least_one(&self) -> bool {
 355         let mut found = false;
 356         self.search(&mut |_, _| {
 357             found = true;
 358             true
 359         });
 360         found
 361     }
 362
 363     pub fn all(self) -> UsageSearchResult {
 364         let mut res = UsageSearchResult::default();
 365         self.search(&mut |file_id, reference| {
 366             res.references.entry(file_id).or_default().push(reference);
 367             false
 368         });
 369         res
 370     }
 371
 372     fn search(&self, sink: &mut dyn FnMut(FileId, FileReference) -> bool) {
 373         let _p = profile::span("FindUsages:search");
 374         let sema = self.sema;
 375
 376         let search_scope = {
 377             let base = self.def.search_scope(sema.db);
 378             match &self.scope {
 379                 None => base,
 380                 Some(scope) => base.intersection(scope),
 381             }
 382         };
 383
 384         let name = match self.def {
 385             // special case crate modules as these do not have a proper name
 386             Definition::Module(module) if module.is_crate_root(self.sema.db) => {
 387                 // FIXME: This assumes the crate name is always equal to its display name when it really isn't
 388                 module
 389                     .krate()
 390                     .display_name(self.sema.db)
 391                     .map(|crate_name| crate_name.crate_name().as_smol_str().clone())
 392             }
 393             _ => {
 394                 let self_kw_refs = || {
 395                     self.include_self_kw_refs.as_ref().and_then(|ty| {
 396                         ty.as_adt()
 397                             .map(|adt| adt.name(self.sema.db))
 398                             .or_else(|| ty.as_builtin().map(|builtin| builtin.name()))
 399                     })
 400                 };
 401                 self.def.name(sema.db).or_else(self_kw_refs).map(|it| it.to_smol_str())
 402             }
 403         };
 404         let name = match &name {
 405             Some(s) => s.as_str(),
 406             None => return,
 407         };
 408
 409         // these can't be closures because rust infers the lifetimes wrong ...
 410         fn match_indices<'a>(
 411             text: &'a str,
 412             name: &'a str,
 413             search_range: TextRange,
 414         ) -> impl Iterator<Item = TextSize> + 'a {
 415             text.match_indices(name).filter_map(move |(idx, _)| {
 416                 let offset: TextSize = idx.try_into().unwrap();
 417                 if !search_range.contains_inclusive(offset) {
 418                     return None;
 419                 }
 420                 Some(offset)
 421             })
 422         }
 423         fn scope_files<'a>(
 424             sema: &'a Semantics<RootDatabase>,
 425             scope: &'a SearchScope,
 426         ) -> impl Iterator<Item = (Arc<String>, FileId, TextRange)> + 'a {
 427             scope.entries.iter().map(|(&file_id, &search_range)| {
 428                 let text = sema.db.file_text(file_id);
 429                 let search_range =
 430                     search_range.unwrap_or_else(|| TextRange::up_to(TextSize::of(text.as_str())));
 431
 432                 (text, file_id, search_range)
 433             })
 434         }
 435
 436         for (text, file_id, search_range) in scope_files(sema, &search_scope) {
 437             let tree = Lazy::new(move || sema.parse(file_id).syntax().clone());
 438
 439             // Search for occurrences of the items name
 440             for offset in match_indices(&text, name, search_range) {
 441                 for name in sema.find_nodes_at_offset_with_descend(&tree, offset) {
 442                     if match name {
 443                         ast::NameLike::NameRef(name_ref) => self.found_name_ref(&name_ref, sink),
 444                         ast::NameLike::Name(name) => self.found_name(&name, sink),
 445                         ast::NameLike::Lifetime(lifetime) => self.found_lifetime(&lifetime, sink),
 446                     } {
 447                         return;
 448                     }
 449                 }
 450             }
 451             // Search for occurrences of the `Self` referring to our type
 452             if let Some(self_ty) = &self.include_self_kw_refs {
 453                 for offset in match_indices(&text, "Self", search_range) {
 454                     for name_ref in sema.find_nodes_at_offset_with_descend(&tree, offset) {
 455                         if self.found_self_ty_name_ref(self_ty, &name_ref, sink) {
 456                             return;
 457                         }
 458                     }
 459                 }
 460             }
 461         }
 462
 463         // Search for `super` and `crate` resolving to our module
 464         match self.def {
 465             Definition::Module(module) => {
 466                 let scope = search_scope.intersection(&SearchScope::module(self.sema.db, module));
 467
 468                 let is_crate_root = module.is_crate_root(self.sema.db);
 469
 470                 for (text, file_id, search_range) in scope_files(sema, &scope) {
 471                     let tree = Lazy::new(move || sema.parse(file_id).syntax().clone());
 472
 473                     for offset in match_indices(&text, "super", search_range) {
 474                         for name_ref in sema.find_nodes_at_offset_with_descend(&tree, offset) {
 475                             if self.found_name_ref(&name_ref, sink) {
 476                                 return;
 477                             }
 478                         }
 479                     }
 480                     if is_crate_root {
 481                         for offset in match_indices(&text, "crate", search_range) {
 482                             for name_ref in sema.find_nodes_at_offset_with_descend(&tree, offset) {
 483                                 if self.found_name_ref(&name_ref, sink) {
 484                                     return;
 485                                 }
 486                             }
 487                         }
 488                     }
 489                 }
 490             }
 491             _ => (),
 492         }
 493
 494         // search for module `self` references in our module's definition source
 495         match self.def {
 496             Definition::Module(module) if self.search_self_mod => {
 497                 let src = module.definition_source(sema.db);
 498                 let file_id = src.file_id.original_file(sema.db);
 499                 let (file_id, search_range) = match src.value {
 500                     ModuleSource::Module(m) => (file_id, Some(m.syntax().text_range())),
 501                     ModuleSource::BlockExpr(b) => (file_id, Some(b.syntax().text_range())),
 502                     ModuleSource::SourceFile(_) => (file_id, None),
 503                 };
 504
 505                 let search_range = if let Some(&range) = search_scope.entries.get(&file_id) {
 506                     match (range, search_range) {
 507                         (None, range) | (range, None) => range,
 508                         (Some(range), Some(search_range)) => match range.intersect(search_range) {
 509                             Some(range) => Some(range),
 510                             None => return,
 511                         },
 512                     }
 513                 } else {
 514                     return;
 515                 };
 516
 517                 let text = sema.db.file_text(file_id);
 518                 let search_range =
 519                     search_range.unwrap_or_else(|| TextRange::up_to(TextSize::of(text.as_str())));
 520
 521                 let tree = Lazy::new(|| sema.parse(file_id).syntax().clone());
 522
 523                 for offset in match_indices(&text, "self", search_range) {
 524                     for name_ref in sema.find_nodes_at_offset_with_descend(&tree, offset) {
 525                         if self.found_self_module_name_ref(&name_ref, sink) {
 526                             return;
 527                         }
 528                     }
 529                 }
 530             }
 531             _ => {}
 532         }
 533     }
 534
 535     fn found_self_ty_name_ref(
 536         &self,
 537         self_ty: &hir::Type,
 538         name_ref: &ast::NameRef,
 539         sink: &mut dyn FnMut(FileId, FileReference) -> bool,
 540     ) -> bool {
 541         match NameRefClass::classify(self.sema, name_ref) {
 542             Some(NameRefClass::Definition(Definition::SelfType(impl_)))
 543                 if impl_.self_ty(self.sema.db) == *self_ty =>
 544             {
 545                 let FileRange { file_id, range } = self.sema.original_range(name_ref.syntax());
 546                 let reference = FileReference {
 547                     range,
 548                     name: ast::NameLike::NameRef(name_ref.clone()),
 549                     category: None,
 550                 };
 551                 sink(file_id, reference)
 552             }
 553             _ => false,
 554         }
 555     }
 556
 557     fn found_self_module_name_ref(
 558         &self,
 559         name_ref: &ast::NameRef,
 560         sink: &mut dyn FnMut(FileId, FileReference) -> bool,
 561     ) -> bool {
 562         match NameRefClass::classify(self.sema, name_ref) {
 563             Some(NameRefClass::Definition(def @ Definition::Module(_))) if def == self.def => {
 564                 let FileRange { file_id, range } = self.sema.original_range(name_ref.syntax());
 565                 let reference = FileReference {
 566                     range,
 567                     name: ast::NameLike::NameRef(name_ref.clone()),
 568                     category: None,
 569                 };
 570                 sink(file_id, reference)
 571             }
 572             _ => false,
 573         }
 574     }
 575
 576     fn found_lifetime(
 577         &self,
 578         lifetime: &ast::Lifetime,
 579         sink: &mut dyn FnMut(FileId, FileReference) -> bool,
 580     ) -> bool {
 581         match NameRefClass::classify_lifetime(self.sema, lifetime) {
 582             Some(NameRefClass::Definition(def)) if def == self.def => {
 583                 let FileRange { file_id, range } = self.sema.original_range(lifetime.syntax());
 584                 let reference = FileReference {
 585                     range,
 586                     name: ast::NameLike::Lifetime(lifetime.clone()),
 587                     category: None,
 588                 };
 589                 sink(file_id, reference)
 590             }
 591             _ => false,
 592         }
 593     }
 594
 595     fn found_name_ref(
 596         &self,
 597         name_ref: &ast::NameRef,
 598         sink: &mut dyn FnMut(FileId, FileReference) -> bool,
 599     ) -> bool {
 600         match NameRefClass::classify(self.sema, name_ref) {
 601             Some(NameRefClass::Definition(def @ Definition::Local(local)))
 602                 if matches!(
 603                     self.local_repr, Some(repr) if repr == local.representative(self.sema.db)
 604                 ) =>
 605             {
 606                 let FileRange { file_id, range } = self.sema.original_range(name_ref.syntax());
 607                 let reference = FileReference {
 608                     range,
 609                     name: ast::NameLike::NameRef(name_ref.clone()),
 610                     category: ReferenceCategory::new(&def, name_ref),
 611                 };
 612                 sink(file_id, reference)
 613             }
 614             Some(NameRefClass::Definition(def)) if def == self.def => {
 615                 let FileRange { file_id, range } = self.sema.original_range(name_ref.syntax());
 616                 let reference = FileReference {
 617                     range,
 618                     name: ast::NameLike::NameRef(name_ref.clone()),
 619                     category: ReferenceCategory::new(&def, name_ref),
 620                 };
 621                 sink(file_id, reference)
 622             }
 623             Some(NameRefClass::Definition(def)) if self.include_self_kw_refs.is_some() => {
 624                 if self.include_self_kw_refs == def_to_ty(self.sema, &def) {
 625                     let FileRange { file_id, range } = self.sema.original_range(name_ref.syntax());
 626                     let reference = FileReference {
 627                         range,
 628                         name: ast::NameLike::NameRef(name_ref.clone()),
 629                         category: ReferenceCategory::new(&def, name_ref),
 630                     };
 631                     sink(file_id, reference)
 632                 } else {
 633                     false
 634                 }
 635             }
 636             Some(NameRefClass::FieldShorthand { local_ref: local, field_ref: field }) => {
 637                 let field = Definition::Field(field);
 638                 let FileRange { file_id, range } = self.sema.original_range(name_ref.syntax());
 639                 let access = match self.def {
 640                     Definition::Field(_) if field == self.def => {
 641                         ReferenceCategory::new(&field, name_ref)
 642                     }
 643                     Definition::Local(_) if matches!(self.local_repr, Some(repr) if repr == local.representative(self.sema.db)) => {
 644                         ReferenceCategory::new(&Definition::Local(local), name_ref)
 645                     }
 646                     _ => return false,
 647                 };
 648                 let reference = FileReference {
 649                     range,
 650                     name: ast::NameLike::NameRef(name_ref.clone()),
 651                     category: access,
 652                 };
 653                 sink(file_id, reference)
 654             }
 655             _ => false,
 656         }
 657     }
 658
 659     fn found_name(
 660         &self,
 661         name: &ast::Name,
 662         sink: &mut dyn FnMut(FileId, FileReference) -> bool,
 663     ) -> bool {
 664         match NameClass::classify(self.sema, name) {
 665             Some(NameClass::PatFieldShorthand { local_def: _, field_ref })
 666                 if matches!(
 667                     self.def, Definition::Field(_) if Definition::Field(field_ref) == self.def
 668                 ) =>
 669             {
 670                 let FileRange { file_id, range } = self.sema.original_range(name.syntax());
 671                 let reference = FileReference {
 672                     range,
 673                     name: ast::NameLike::Name(name.clone()),
 674                     // FIXME: mutable patterns should have `Write` access
 675                     category: Some(ReferenceCategory::Read),
 676                 };
 677                 sink(file_id, reference)
 678             }
 679             Some(NameClass::ConstReference(def)) if self.def == def => {
 680                 let FileRange { file_id, range } = self.sema.original_range(name.syntax());
 681                 let reference = FileReference {
 682                     range,
 683                     name: ast::NameLike::Name(name.clone()),
 684                     category: None,
 685                 };
 686                 sink(file_id, reference)
 687             }
 688             Some(NameClass::Definition(def @ Definition::Local(local))) if def != self.def => {
 689                 if matches!(
 690                     self.local_repr,
 691                     Some(repr) if local.representative(self.sema.db) == repr
 692                 ) {
 693                     let FileRange { file_id, range } = self.sema.original_range(name.syntax());
 694                     let reference = FileReference {
 695                         range,
 696                         name: ast::NameLike::Name(name.clone()),
 697                         category: None,
 698                     };
 699                     return sink(file_id, reference);
 700                 }
 701                 false
 702             }
 703             // Resolve trait impl function definitions to the trait definition's version if self.def is the trait definition's
 704             Some(NameClass::Definition(def)) if def != self.def => {
 705                 /* poor man's try block */
 706                 (|| {
 707                     let this_trait = self
 708                         .def
 709                         .as_assoc_item(self.sema.db)?
 710                         .containing_trait_or_trait_impl(self.sema.db)?;
 711                     let trait_ = def
 712                         .as_assoc_item(self.sema.db)?
 713                         .containing_trait_or_trait_impl(self.sema.db)?;
 714                     (trait_ == this_trait && self.def.name(self.sema.db) == def.name(self.sema.db))
 715                         .then(|| {
 716                             let FileRange { file_id, range } =
 717                                 self.sema.original_range(name.syntax());
 718                             let reference = FileReference {
 719                                 range,
 720                                 name: ast::NameLike::Name(name.clone()),
 721                                 category: None,
 722                             };
 723                             sink(file_id, reference)
 724                         })
 725                 })()
 726                 .unwrap_or(false)
 727             }
 728             _ => false,
 729         }
 730     }
 731 }
 732
 733 fn def_to_ty(sema: &Semantics<RootDatabase>, def: &Definition) -> Option<hir::Type> {
 734     match def {
 735         Definition::Adt(adt) => Some(adt.ty(sema.db)),
 736         Definition::TypeAlias(it) => Some(it.ty(sema.db)),
 737         Definition::BuiltinType(it) => Some(it.ty(sema.db)),
 738         Definition::SelfType(it) => Some(it.self_ty(sema.db)),
 739         _ => None,
 740     }
 741 }
 742
 743 impl ReferenceCategory {
 744     fn new(def: &Definition, r: &ast::NameRef) -> Option<ReferenceCategory> {
 745         // Only Locals and Fields have accesses for now.
 746         if !matches!(def, Definition::Local(_) | Definition::Field(_)) {
 747             return None;
 748         }
 749
 750         let mode = r.syntax().ancestors().find_map(|node| {
 751         match_ast! {
 752             match node {
 753                 ast::BinExpr(expr) => {
 754                     if matches!(expr.op_kind()?, ast::BinaryOp::Assignment { .. }) {
 755                         // If the variable or field ends on the LHS's end then it's a Write (covers fields and locals).
 756                         // FIXME: This is not terribly accurate.
 757                         if let Some(lhs) = expr.lhs() {
 758                             if lhs.syntax().text_range().end() == r.syntax().text_range().end() {
 759                                 return Some(ReferenceCategory::Write);
 760                             }
 761                         }
 762                     }
 763                     Some(ReferenceCategory::Read)
 764                 },
 765                 _ => None
 766             }
 767         }
 768     });
 769
 770         // Default Locals and Fields to read
 771         mode.or(Some(ReferenceCategory::Read))
 772     }
 773 }