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