crates/ide_db/src/defs.rs

   1 //! `NameDefinition` keeps information about the element we want to search references for.
   2 //! The element is represented by `NameKind`. It's located inside some `container` and
   3 //! has a `visibility`, which defines a search scope.
   4 //! Note that the reference search is possible for not all of the classified items.
   5
   6 // FIXME: this badly needs rename/rewrite (matklad, 2020-02-06).
   7
   8 use hir::{
   9     db::HirDatabase, Crate, Field, GenericParam, HasVisibility, Impl, Label, Local, MacroDef,
  10     Module, ModuleDef, Name, PathResolution, Semantics, Visibility,
  11 };
  12 use syntax::{
  13     ast::{self, AstNode, PathSegmentKind},
  14     match_ast, SyntaxKind, SyntaxNode,
  15 };
  16
  17 use crate::RootDatabase;
  18
  19 // FIXME: a more precise name would probably be `Symbol`?
  20 #[derive(Debug, PartialEq, Eq, Copy, Clone)]
  21 pub enum Definition {
  22     Macro(MacroDef),
  23     Field(Field),
  24     ModuleDef(ModuleDef),
  25     SelfType(Impl),
  26     Local(Local),
  27     GenericParam(GenericParam),
  28     Label(Label),
  29 }
  30
  31 impl Definition {
  32     pub fn module(&self, db: &RootDatabase) -> Option<Module> {
  33         match self {
  34             Definition::Macro(it) => it.module(db),
  35             Definition::Field(it) => Some(it.parent_def(db).module(db)),
  36             Definition::ModuleDef(it) => it.module(db),
  37             Definition::SelfType(it) => Some(it.module(db)),
  38             Definition::Local(it) => Some(it.module(db)),
  39             Definition::GenericParam(it) => Some(it.module(db)),
  40             Definition::Label(it) => Some(it.module(db)),
  41         }
  42     }
  43
  44     pub fn visibility(&self, db: &RootDatabase) -> Option<Visibility> {
  45         match self {
  46             Definition::Macro(_) => None,
  47             Definition::Field(sf) => Some(sf.visibility(db)),
  48             Definition::ModuleDef(def) => def.definition_visibility(db),
  49             Definition::SelfType(_) => None,
  50             Definition::Local(_) => None,
  51             Definition::GenericParam(_) => None,
  52             Definition::Label(_) => None,
  53         }
  54     }
  55
  56     pub fn name(&self, db: &RootDatabase) -> Option<Name> {
  57         let name = match self {
  58             Definition::Macro(it) => it.name(db)?,
  59             Definition::Field(it) => it.name(db),
  60             Definition::ModuleDef(def) => match def {
  61                 hir::ModuleDef::Module(it) => it.name(db)?,
  62                 hir::ModuleDef::Function(it) => it.name(db),
  63                 hir::ModuleDef::Adt(def) => match def {
  64                     hir::Adt::Struct(it) => it.name(db),
  65                     hir::Adt::Union(it) => it.name(db),
  66                     hir::Adt::Enum(it) => it.name(db),
  67                 },
  68                 hir::ModuleDef::Variant(it) => it.name(db),
  69                 hir::ModuleDef::Const(it) => it.name(db)?,
  70                 hir::ModuleDef::Static(it) => it.name(db)?,
  71                 hir::ModuleDef::Trait(it) => it.name(db),
  72                 hir::ModuleDef::TypeAlias(it) => it.name(db),
  73                 hir::ModuleDef::BuiltinType(_) => return None,
  74             },
  75             Definition::SelfType(_) => return None,
  76             Definition::Local(it) => it.name(db)?,
  77             Definition::GenericParam(it) => it.name(db),
  78             Definition::Label(it) => it.name(db),
  79         };
  80         Some(name)
  81     }
  82 }
  83
  84 #[derive(Debug)]
  85 pub enum NameClass {
  86     ExternCrate(Crate),
  87     Definition(Definition),
  88     /// `None` in `if let None = Some(82) {}`.
  89     ConstReference(Definition),
  90     /// `field` in `if let Foo { field } = foo`.
  91     PatFieldShorthand {
  92         local_def: Local,
  93         field_ref: Definition,
  94     },
  95 }
  96
  97 impl NameClass {
  98     /// `Definition` defined by this name.
  99     pub fn defined(self, db: &dyn HirDatabase) -> Option<Definition> {
 100         let res = match self {
 101             NameClass::ExternCrate(krate) => Definition::ModuleDef(krate.root_module(db).into()),
 102             NameClass::Definition(it) => it,
 103             NameClass::ConstReference(_) => return None,
 104             NameClass::PatFieldShorthand { local_def, field_ref: _ } => {
 105                 Definition::Local(local_def)
 106             }
 107         };
 108         Some(res)
 109     }
 110
 111     /// `Definition` referenced or defined by this name.
 112     pub fn referenced_or_defined(self, db: &dyn HirDatabase) -> Definition {
 113         match self {
 114             NameClass::ExternCrate(krate) => Definition::ModuleDef(krate.root_module(db).into()),
 115             NameClass::Definition(it) | NameClass::ConstReference(it) => it,
 116             NameClass::PatFieldShorthand { local_def: _, field_ref } => field_ref,
 117         }
 118     }
 119
 120     pub fn classify(sema: &Semantics<RootDatabase>, name: &ast::Name) -> Option<NameClass> {
 121         let _p = profile::span("classify_name");
 122
 123         let parent = name.syntax().parent()?;
 124
 125         if let Some(bind_pat) = ast::IdentPat::cast(parent.clone()) {
 126             if let Some(def) = sema.resolve_bind_pat_to_const(&bind_pat) {
 127                 return Some(NameClass::ConstReference(Definition::ModuleDef(def)));
 128             }
 129         }
 130
 131         match_ast! {
 132             match parent {
 133                 ast::Rename(it) => {
 134                     if let Some(use_tree) = it.syntax().parent().and_then(ast::UseTree::cast) {
 135                         let path = use_tree.path()?;
 136                         let path_segment = path.segment()?;
 137                         let name_ref_class = path_segment
 138                             .kind()
 139                             .and_then(|kind| {
 140                                 match kind {
 141                                     // The rename might be from a `self` token, so fallback to the name higher
 142                                     // in the use tree.
 143                                     PathSegmentKind::SelfKw => {
 144                                         let use_tree = use_tree
 145                                             .syntax()
 146                                             .parent()
 147                                             .as_ref()
 148                                             // Skip over UseTreeList
 149                                             .and_then(SyntaxNode::parent)
 150                                             .and_then(ast::UseTree::cast)?;
 151                                         let path = use_tree.path()?;
 152                                         let path_segment = path.segment()?;
 153                                         path_segment.name_ref()
 154                                     },
 155                                     PathSegmentKind::Name(name_ref) => Some(name_ref),
 156                                     _ => return None,
 157                                 }
 158                             })
 159                             .and_then(|name_ref| NameRefClass::classify(sema, &name_ref))?;
 160
 161                         Some(NameClass::Definition(name_ref_class.referenced(sema.db)))
 162                     } else {
 163                         let extern_crate = it.syntax().parent().and_then(ast::ExternCrate::cast)?;
 164                         let resolved = sema.resolve_extern_crate(&extern_crate)?;
 165                         Some(NameClass::ExternCrate(resolved))
 166                     }
 167                 },
 168                 ast::IdentPat(it) => {
 169                     let local = sema.to_def(&it)?;
 170
 171                     if let Some(record_pat_field) = it.syntax().parent().and_then(ast::RecordPatField::cast) {
 172                         if record_pat_field.name_ref().is_none() {
 173                             if let Some(field) = sema.resolve_record_pat_field(&record_pat_field) {
 174                                 let field = Definition::Field(field);
 175                                 return Some(NameClass::PatFieldShorthand { local_def: local, field_ref: field });
 176                             }
 177                         }
 178                     }
 179
 180                     Some(NameClass::Definition(Definition::Local(local)))
 181                 },
 182                 ast::SelfParam(it) => {
 183                     let def = sema.to_def(&it)?;
 184                     Some(NameClass::Definition(Definition::Local(def.into())))
 185                 },
 186                 ast::RecordField(it) => {
 187                     let field: hir::Field = sema.to_def(&it)?;
 188                     Some(NameClass::Definition(Definition::Field(field)))
 189                 },
 190                 ast::Module(it) => {
 191                     let def = sema.to_def(&it)?;
 192                     Some(NameClass::Definition(Definition::ModuleDef(def.into())))
 193                 },
 194                 ast::Struct(it) => {
 195                     let def: hir::Struct = sema.to_def(&it)?;
 196                     Some(NameClass::Definition(Definition::ModuleDef(def.into())))
 197                 },
 198                 ast::Union(it) => {
 199                     let def: hir::Union = sema.to_def(&it)?;
 200                     Some(NameClass::Definition(Definition::ModuleDef(def.into())))
 201                 },
 202                 ast::Enum(it) => {
 203                     let def: hir::Enum = sema.to_def(&it)?;
 204                     Some(NameClass::Definition(Definition::ModuleDef(def.into())))
 205                 },
 206                 ast::Trait(it) => {
 207                     let def: hir::Trait = sema.to_def(&it)?;
 208                     Some(NameClass::Definition(Definition::ModuleDef(def.into())))
 209                 },
 210                 ast::Static(it) => {
 211                     let def: hir::Static = sema.to_def(&it)?;
 212                     Some(NameClass::Definition(Definition::ModuleDef(def.into())))
 213                 },
 214                 ast::Variant(it) => {
 215                     let def: hir::Variant = sema.to_def(&it)?;
 216                     Some(NameClass::Definition(Definition::ModuleDef(def.into())))
 217                 },
 218                 ast::Fn(it) => {
 219                     let def: hir::Function = sema.to_def(&it)?;
 220                     Some(NameClass::Definition(Definition::ModuleDef(def.into())))
 221                 },
 222                 ast::Const(it) => {
 223                     let def: hir::Const = sema.to_def(&it)?;
 224                     Some(NameClass::Definition(Definition::ModuleDef(def.into())))
 225                 },
 226                 ast::TypeAlias(it) => {
 227                     let def: hir::TypeAlias = sema.to_def(&it)?;
 228                     Some(NameClass::Definition(Definition::ModuleDef(def.into())))
 229                 },
 230                 ast::MacroRules(it) => {
 231                     let def = sema.to_def(&it)?;
 232                     Some(NameClass::Definition(Definition::Macro(def)))
 233                 },
 234                 ast::TypeParam(it) => {
 235                     let def = sema.to_def(&it)?;
 236                     Some(NameClass::Definition(Definition::GenericParam(def.into())))
 237                 },
 238                 ast::ConstParam(it) => {
 239                     let def = sema.to_def(&it)?;
 240                     Some(NameClass::Definition(Definition::GenericParam(def.into())))
 241                 },
 242                 _ => None,
 243             }
 244         }
 245     }
 246
 247     pub fn classify_lifetime(
 248         sema: &Semantics<RootDatabase>,
 249         lifetime: &ast::Lifetime,
 250     ) -> Option<NameClass> {
 251         let _p = profile::span("classify_lifetime").detail(|| lifetime.to_string());
 252         let parent = lifetime.syntax().parent()?;
 253
 254         match_ast! {
 255             match parent {
 256                 ast::LifetimeParam(it) => {
 257                     let def = sema.to_def(&it)?;
 258                     Some(NameClass::Definition(Definition::GenericParam(def.into())))
 259                 },
 260                 ast::Label(it) => {
 261                     let def = sema.to_def(&it)?;
 262                     Some(NameClass::Definition(Definition::Label(def)))
 263                 },
 264                 _ => None,
 265             }
 266         }
 267     }
 268 }
 269
 270 #[derive(Debug)]
 271 pub enum NameRefClass {
 272     ExternCrate(Crate),
 273     Definition(Definition),
 274     FieldShorthand { local_ref: Local, field_ref: Definition },
 275 }
 276
 277 impl NameRefClass {
 278     /// `Definition`, which this name refers to.
 279     pub fn referenced(self, db: &dyn HirDatabase) -> Definition {
 280         match self {
 281             NameRefClass::ExternCrate(krate) => Definition::ModuleDef(krate.root_module(db).into()),
 282             NameRefClass::Definition(def) => def,
 283             NameRefClass::FieldShorthand { local_ref, field_ref: _ } => {
 284                 // FIXME: this is inherently ambiguous -- this name refers to
 285                 // two different defs....
 286                 Definition::Local(local_ref)
 287             }
 288         }
 289     }
 290
 291     // Note: we don't have unit-tests for this rather important function.
 292     // It is primarily exercised via goto definition tests in `ide`.
 293     pub fn classify(
 294         sema: &Semantics<RootDatabase>,
 295         name_ref: &ast::NameRef,
 296     ) -> Option<NameRefClass> {
 297         let _p = profile::span("classify_name_ref").detail(|| name_ref.to_string());
 298
 299         let parent = name_ref.syntax().parent()?;
 300
 301         if let Some(method_call) = ast::MethodCallExpr::cast(parent.clone()) {
 302             if let Some(func) = sema.resolve_method_call(&method_call) {
 303                 return Some(NameRefClass::Definition(Definition::ModuleDef(func.into())));
 304             }
 305         }
 306
 307         if let Some(field_expr) = ast::FieldExpr::cast(parent.clone()) {
 308             if let Some(field) = sema.resolve_field(&field_expr) {
 309                 return Some(NameRefClass::Definition(Definition::Field(field)));
 310             }
 311         }
 312
 313         if let Some(record_field) = ast::RecordExprField::for_field_name(name_ref) {
 314             if let Some((field, local)) = sema.resolve_record_field(&record_field) {
 315                 let field = Definition::Field(field);
 316                 let res = match local {
 317                     None => NameRefClass::Definition(field),
 318                     Some(local) => {
 319                         NameRefClass::FieldShorthand { field_ref: field, local_ref: local }
 320                     }
 321                 };
 322                 return Some(res);
 323             }
 324         }
 325
 326         if let Some(record_pat_field) = ast::RecordPatField::cast(parent.clone()) {
 327             if let Some(field) = sema.resolve_record_pat_field(&record_pat_field) {
 328                 let field = Definition::Field(field);
 329                 return Some(NameRefClass::Definition(field));
 330             }
 331         }
 332
 333         if ast::AssocTypeArg::cast(parent.clone()).is_some() {
 334             // `Trait<Assoc = Ty>`
 335             //        ^^^^^
 336             let path = name_ref.syntax().ancestors().find_map(ast::Path::cast)?;
 337             let resolved = sema.resolve_path(&path)?;
 338             if let PathResolution::Def(ModuleDef::Trait(tr)) = resolved {
 339                 if let Some(ty) = tr
 340                     .items(sema.db)
 341                     .iter()
 342                     .filter_map(|assoc| match assoc {
 343                         hir::AssocItem::TypeAlias(it) => Some(*it),
 344                         _ => None,
 345                     })
 346                     .find(|alias| alias.name(sema.db).to_string() == **name_ref.text())
 347                 {
 348                     return Some(NameRefClass::Definition(Definition::ModuleDef(
 349                         ModuleDef::TypeAlias(ty),
 350                     )));
 351                 }
 352             }
 353         }
 354
 355         if let Some(macro_call) = parent.ancestors().find_map(ast::MacroCall::cast) {
 356             if let Some(path) = macro_call.path() {
 357                 if path.qualifier().is_none() {
 358                     // Only use this to resolve single-segment macro calls like `foo!()`. Multi-segment
 359                     // paths are handled below (allowing `log$0::info!` to resolve to the log crate).
 360                     if let Some(macro_def) = sema.resolve_macro_call(&macro_call) {
 361                         return Some(NameRefClass::Definition(Definition::Macro(macro_def)));
 362                     }
 363                 }
 364             }
 365         }
 366
 367         if let Some(path) = name_ref.syntax().ancestors().find_map(ast::Path::cast) {
 368             if let Some(resolved) = sema.resolve_path(&path) {
 369                 return Some(NameRefClass::Definition(resolved.into()));
 370             }
 371         }
 372
 373         let extern_crate = ast::ExternCrate::cast(parent)?;
 374         let resolved = sema.resolve_extern_crate(&extern_crate)?;
 375         Some(NameRefClass::ExternCrate(resolved))
 376     }
 377
 378     pub fn classify_lifetime(
 379         sema: &Semantics<RootDatabase>,
 380         lifetime: &ast::Lifetime,
 381     ) -> Option<NameRefClass> {
 382         let _p = profile::span("classify_lifetime_ref").detail(|| lifetime.to_string());
 383         let parent = lifetime.syntax().parent()?;
 384         match parent.kind() {
 385             SyntaxKind::BREAK_EXPR | SyntaxKind::CONTINUE_EXPR => {
 386                 sema.resolve_label(lifetime).map(Definition::Label).map(NameRefClass::Definition)
 387             }
 388             SyntaxKind::LIFETIME_ARG
 389             | SyntaxKind::SELF_PARAM
 390             | SyntaxKind::TYPE_BOUND
 391             | SyntaxKind::WHERE_PRED
 392             | SyntaxKind::REF_TYPE => sema
 393                 .resolve_lifetime_param(lifetime)
 394                 .map(GenericParam::LifetimeParam)
 395                 .map(Definition::GenericParam)
 396                 .map(NameRefClass::Definition),
 397             // lifetime bounds, as in the 'b in 'a: 'b aren't wrapped in TypeBound nodes so we gotta check
 398             // if our lifetime is in a LifetimeParam without being the constrained lifetime
 399             _ if ast::LifetimeParam::cast(parent).and_then(|param| param.lifetime()).as_ref()
 400                 != Some(lifetime) =>
 401             {
 402                 sema.resolve_lifetime_param(lifetime)
 403                     .map(GenericParam::LifetimeParam)
 404                     .map(Definition::GenericParam)
 405                     .map(NameRefClass::Definition)
 406             }
 407             _ => None,
 408         }
 409     }
 410 }
 411
 412 impl From<PathResolution> for Definition {
 413     fn from(path_resolution: PathResolution) -> Self {
 414         match path_resolution {
 415             PathResolution::Def(def) => Definition::ModuleDef(def),
 416             PathResolution::AssocItem(item) => {
 417                 let def = match item {
 418                     hir::AssocItem::Function(it) => it.into(),
 419                     hir::AssocItem::Const(it) => it.into(),
 420                     hir::AssocItem::TypeAlias(it) => it.into(),
 421                 };
 422                 Definition::ModuleDef(def)
 423             }
 424             PathResolution::Local(local) => Definition::Local(local),
 425             PathResolution::TypeParam(par) => Definition::GenericParam(par.into()),
 426             PathResolution::Macro(def) => Definition::Macro(def),
 427             PathResolution::SelfType(impl_def) => Definition::SelfType(impl_def),
 428             PathResolution::ConstParam(par) => Definition::GenericParam(par.into()),
 429         }
 430     }
 431 }