crates/ide/src/syntax_highlighting/highlight.rs

   1 //! Computes color for a single element.
   2
   3 use hir::{AsAssocItem, HasVisibility, Semantics};
   4 use ide_db::{
   5     defs::{Definition, NameClass, NameRefClass},
   6     RootDatabase, SymbolKind,
   7 };
   8 use rustc_hash::FxHashMap;
   9 use syntax::{
  10     ast, AstNode, AstToken, NodeOrToken, SyntaxElement,
  11     SyntaxKind::{self, *},
  12     SyntaxNode, SyntaxToken, T,
  13 };
  14
  15 use crate::{
  16     syntax_highlighting::tags::{HlOperator, HlPunct},
  17     Highlight, HlMod, HlTag,
  18 };
  19
  20 pub(super) fn element(
  21     sema: &Semantics<RootDatabase>,
  22     krate: Option<hir::Crate>,
  23     bindings_shadow_count: &mut FxHashMap<hir::Name, u32>,
  24     syntactic_name_ref_highlighting: bool,
  25     element: SyntaxElement,
  26 ) -> Option<(Highlight, Option<u64>)> {
  27     let db = sema.db;
  28     let mut binding_hash = None;
  29     let highlight: Highlight = match element.kind() {
  30         FN => {
  31             bindings_shadow_count.clear();
  32             return None;
  33         }
  34
  35         // Highlight definitions depending on the "type" of the definition.
  36         NAME => {
  37             let name = element.into_node().and_then(ast::Name::cast).unwrap();
  38             let name_kind = NameClass::classify(sema, &name);
  39
  40             if let Some(NameClass::Definition(Definition::Local(local))) = &name_kind {
  41                 if let Some(name) = local.name(db) {
  42                     let shadow_count = bindings_shadow_count.entry(name.clone()).or_default();
  43                     *shadow_count += 1;
  44                     binding_hash = Some(calc_binding_hash(&name, *shadow_count))
  45                 }
  46             };
  47
  48             match name_kind {
  49                 Some(NameClass::ExternCrate(_)) => SymbolKind::Module.into(),
  50                 Some(NameClass::Definition(def)) => {
  51                     let mut h = highlight_def(db, krate, def) | HlMod::Definition;
  52                     if let Definition::ModuleDef(hir::ModuleDef::Trait(trait_)) = &def {
  53                         if trait_.is_unsafe(db) {
  54                             h |= HlMod::Unsafe;
  55                         }
  56                     }
  57                     h
  58                 }
  59                 Some(NameClass::ConstReference(def)) => highlight_def(db, krate, def),
  60                 Some(NameClass::PatFieldShorthand { field_ref, .. }) => {
  61                     let mut h = HlTag::Symbol(SymbolKind::Field).into();
  62                     if let Definition::Field(field) = field_ref {
  63                         if let hir::VariantDef::Union(_) = field.parent_def(db) {
  64                             h |= HlMod::Unsafe;
  65                         }
  66                     }
  67                     h
  68                 }
  69                 None => highlight_name_by_syntax(name) | HlMod::Definition,
  70             }
  71         }
  72         // Highlight references like the definitions they resolve to
  73         NAME_REF if element.ancestors().any(|it| it.kind() == ATTR) => {
  74             // FIXME: We highlight paths in attributes slightly differently to work around this module
  75             // currently not knowing about tool attributes and rustc builtin attributes as
  76             // we do not want to resolve those to functions that may be defined in scope.
  77             let name_ref = element.into_node().and_then(ast::NameRef::cast).unwrap();
  78             match NameRefClass::classify(sema, &name_ref) {
  79                 Some(name_class) => match name_class {
  80                     NameRefClass::Definition(Definition::ModuleDef(hir::ModuleDef::Module(_)))
  81                         if name_ref
  82                             .syntax()
  83                             .ancestors()
  84                             .find_map(ast::Path::cast)
  85                             .map_or(false, |it| it.parent_path().is_some()) =>
  86                     {
  87                         HlTag::Symbol(SymbolKind::Module)
  88                     }
  89                     NameRefClass::Definition(Definition::Macro(m))
  90                         if m.kind() == hir::MacroKind::Attr =>
  91                     {
  92                         HlTag::Symbol(SymbolKind::Macro)
  93                     }
  94                     _ => HlTag::BuiltinAttr,
  95                 },
  96                 None => HlTag::BuiltinAttr,
  97             }
  98             .into()
  99         }
 100         NAME_REF => {
 101             let name_ref = element.into_node().and_then(ast::NameRef::cast).unwrap();
 102             highlight_method_call_by_name_ref(sema, krate, &name_ref).unwrap_or_else(|| {
 103                 let name_class = match NameRefClass::classify(sema, &name_ref) {
 104                     Some(name_kind) => name_kind,
 105                     None => {
 106                         return if syntactic_name_ref_highlighting {
 107                             highlight_name_ref_by_syntax(name_ref, sema, krate)
 108                         } else {
 109                             HlTag::UnresolvedReference.into()
 110                         }
 111                     }
 112                 };
 113                 let h = match name_class {
 114                     NameRefClass::ExternCrate(_) => SymbolKind::Module.into(),
 115                     NameRefClass::Definition(def) => {
 116                         if let Definition::Local(local) = &def {
 117                             if let Some(name) = local.name(db) {
 118                                 let shadow_count =
 119                                     bindings_shadow_count.entry(name.clone()).or_default();
 120                                 binding_hash = Some(calc_binding_hash(&name, *shadow_count))
 121                             }
 122                         };
 123
 124                         let mut h = highlight_def(db, krate, def);
 125
 126                         match def {
 127                             Definition::Local(local)
 128                                 if is_consumed_lvalue(name_ref.syntax(), &local, db) =>
 129                             {
 130                                 h |= HlMod::Consuming;
 131                             }
 132                             Definition::ModuleDef(hir::ModuleDef::Trait(trait_))
 133                                 if trait_.is_unsafe(db) =>
 134                             {
 135                                 if ast::Impl::for_trait_name_ref(&name_ref).is_some() {
 136                                     h |= HlMod::Unsafe;
 137                                 }
 138                             }
 139                             Definition::Field(field) => {
 140                                 if let Some(parent) = name_ref.syntax().parent() {
 141                                     if matches!(parent.kind(), FIELD_EXPR | RECORD_PAT_FIELD) {
 142                                         if let hir::VariantDef::Union(_) = field.parent_def(db) {
 143                                             h |= HlMod::Unsafe;
 144                                         }
 145                                     }
 146                                 }
 147                             }
 148                             _ => (),
 149                         }
 150
 151                         h
 152                     }
 153                     NameRefClass::FieldShorthand { .. } => SymbolKind::Field.into(),
 154                 };
 155                 if h.tag == HlTag::Symbol(SymbolKind::Module) && name_ref.self_token().is_some() {
 156                     SymbolKind::SelfParam.into()
 157                 } else {
 158                     h
 159                 }
 160             })
 161         }
 162
 163         // Simple token-based highlighting
 164         COMMENT => {
 165             let comment = element.into_token().and_then(ast::Comment::cast)?;
 166             let h = HlTag::Comment;
 167             match comment.kind().doc {
 168                 Some(_) => h | HlMod::Documentation,
 169                 None => h.into(),
 170             }
 171         }
 172         STRING | BYTE_STRING => HlTag::StringLiteral.into(),
 173         ATTR => HlTag::Attribute.into(),
 174         INT_NUMBER if element.ancestors().nth(1).map_or(false, |it| it.kind() == FIELD_EXPR) => {
 175             SymbolKind::Field.into()
 176         }
 177         INT_NUMBER | FLOAT_NUMBER => HlTag::NumericLiteral.into(),
 178         BYTE => HlTag::ByteLiteral.into(),
 179         CHAR => HlTag::CharLiteral.into(),
 180         QUESTION => HlTag::Operator(HlOperator::Other) | HlMod::ControlFlow,
 181         LIFETIME => {
 182             let lifetime = element.into_node().and_then(ast::Lifetime::cast).unwrap();
 183
 184             match NameClass::classify_lifetime(sema, &lifetime) {
 185                 Some(NameClass::Definition(def)) => {
 186                     highlight_def(db, krate, def) | HlMod::Definition
 187                 }
 188                 None => match NameRefClass::classify_lifetime(sema, &lifetime) {
 189                     Some(NameRefClass::Definition(def)) => highlight_def(db, krate, def),
 190                     _ => SymbolKind::LifetimeParam.into(),
 191                 },
 192                 _ => Highlight::from(SymbolKind::LifetimeParam) | HlMod::Definition,
 193             }
 194         }
 195         IDENT if parent_matches::<ast::TokenTree>(&element) => HlTag::None.into(),
 196         p if p.is_punct() => match p {
 197             T![&] if parent_matches::<ast::BinExpr>(&element) => HlOperator::Bitwise.into(),
 198             T![&] => {
 199                 let h = HlTag::Operator(HlOperator::Other).into();
 200                 let is_unsafe = element
 201                     .parent()
 202                     .and_then(ast::RefExpr::cast)
 203                     .map_or(false, |ref_expr| sema.is_unsafe_ref_expr(&ref_expr));
 204                 if is_unsafe {
 205                     h | HlMod::Unsafe
 206                 } else {
 207                     h
 208                 }
 209             }
 210             T![::] | T![->] | T![=>] | T![..] | T![=] | T![@] | T![.] => HlOperator::Other.into(),
 211             T![!] if parent_matches::<ast::MacroCall>(&element) => SymbolKind::Macro.into(),
 212             T![!] if parent_matches::<ast::NeverType>(&element) => HlTag::BuiltinType.into(),
 213             T![!] if parent_matches::<ast::PrefixExpr>(&element) => HlOperator::Logical.into(),
 214             T![*] if parent_matches::<ast::PtrType>(&element) => HlTag::Keyword.into(),
 215             T![*] if parent_matches::<ast::PrefixExpr>(&element) => {
 216                 let prefix_expr = element.parent().and_then(ast::PrefixExpr::cast)?;
 217
 218                 let expr = prefix_expr.expr()?;
 219                 let ty = sema.type_of_expr(&expr)?;
 220                 if ty.is_raw_ptr() {
 221                     HlTag::Operator(HlOperator::Other) | HlMod::Unsafe
 222                 } else if let Some(ast::PrefixOp::Deref) = prefix_expr.op_kind() {
 223                     HlOperator::Other.into()
 224                 } else {
 225                     HlPunct::Other.into()
 226                 }
 227             }
 228             T![-] if parent_matches::<ast::PrefixExpr>(&element) => {
 229                 let prefix_expr = element.parent().and_then(ast::PrefixExpr::cast)?;
 230
 231                 let expr = prefix_expr.expr()?;
 232                 match expr {
 233                     ast::Expr::Literal(_) => HlTag::NumericLiteral,
 234                     _ => HlTag::Operator(HlOperator::Other),
 235                 }
 236                 .into()
 237             }
 238             _ if parent_matches::<ast::PrefixExpr>(&element) => HlOperator::Other.into(),
 239             T![+] | T![-] | T![*] | T![/] | T![+=] | T![-=] | T![*=] | T![/=]
 240                 if parent_matches::<ast::BinExpr>(&element) =>
 241             {
 242                 HlOperator::Arithmetic.into()
 243             }
 244             T![|] | T![&] | T![!] | T![^] | T![|=] | T![&=] | T![^=]
 245                 if parent_matches::<ast::BinExpr>(&element) =>
 246             {
 247                 HlOperator::Bitwise.into()
 248             }
 249             T![&&] | T![||] if parent_matches::<ast::BinExpr>(&element) => {
 250                 HlOperator::Logical.into()
 251             }
 252             T![>] | T![<] | T![==] | T![>=] | T![<=] | T![!=]
 253                 if parent_matches::<ast::BinExpr>(&element) =>
 254             {
 255                 HlOperator::Comparison.into()
 256             }
 257             _ if parent_matches::<ast::BinExpr>(&element) => HlOperator::Other.into(),
 258             _ if parent_matches::<ast::RangeExpr>(&element) => HlOperator::Other.into(),
 259             _ if parent_matches::<ast::RangePat>(&element) => HlOperator::Other.into(),
 260             _ if parent_matches::<ast::RestPat>(&element) => HlOperator::Other.into(),
 261             _ if parent_matches::<ast::Attr>(&element) => HlTag::Attribute.into(),
 262             kind => match kind {
 263                 T!['['] | T![']'] => HlPunct::Bracket,
 264                 T!['{'] | T!['}'] => HlPunct::Brace,
 265                 T!['('] | T![')'] => HlPunct::Parenthesis,
 266                 T![<] | T![>] => HlPunct::Angle,
 267                 T![,] => HlPunct::Comma,
 268                 T![:] => HlPunct::Colon,
 269                 T![;] => HlPunct::Semi,
 270                 T![.] => HlPunct::Dot,
 271                 _ => HlPunct::Other,
 272             }
 273             .into(),
 274         },
 275
 276         k if k.is_keyword() => {
 277             let h = Highlight::new(HlTag::Keyword);
 278             match k {
 279                 T![await] => h | HlMod::Async | HlMod::ControlFlow,
 280                 T![break]
 281                 | T![continue]
 282                 | T![else]
 283                 | T![if]
 284                 | T![in]
 285                 | T![loop]
 286                 | T![match]
 287                 | T![return]
 288                 | T![while]
 289                 | T![yield] => h | HlMod::ControlFlow,
 290                 T![for] if !is_child_of_impl(&element) => h | HlMod::ControlFlow,
 291                 T![unsafe] => h | HlMod::Unsafe,
 292                 T![true] | T![false] => HlTag::BoolLiteral.into(),
 293                 // self is handled as either a Name or NameRef already
 294                 T![self] => return None,
 295                 T![ref] => element
 296                     .parent()
 297                     .and_then(ast::IdentPat::cast)
 298                     .and_then(|ident_pat| {
 299                         if sema.is_unsafe_ident_pat(&ident_pat) {
 300                             Some(HlMod::Unsafe)
 301                         } else {
 302                             None
 303                         }
 304                     })
 305                     .map(|modifier| h | modifier)
 306                     .unwrap_or(h),
 307                 T![async] => h | HlMod::Async,
 308                 _ => h,
 309             }
 310         }
 311
 312         _ => return None,
 313     };
 314
 315     return Some((highlight, binding_hash));
 316
 317     fn calc_binding_hash(name: &hir::Name, shadow_count: u32) -> u64 {
 318         fn hash<T: std::hash::Hash + std::fmt::Debug>(x: T) -> u64 {
 319             use std::{collections::hash_map::DefaultHasher, hash::Hasher};
 320
 321             let mut hasher = DefaultHasher::new();
 322             x.hash(&mut hasher);
 323             hasher.finish()
 324         }
 325
 326         hash((name, shadow_count))
 327     }
 328 }
 329 fn highlight_def(db: &RootDatabase, krate: Option<hir::Crate>, def: Definition) -> Highlight {
 330     let mut h = match def {
 331         Definition::Macro(_) => Highlight::new(HlTag::Symbol(SymbolKind::Macro)),
 332         Definition::Field(_) => Highlight::new(HlTag::Symbol(SymbolKind::Field)),
 333         Definition::ModuleDef(def) => match def {
 334             hir::ModuleDef::Module(_) => Highlight::new(HlTag::Symbol(SymbolKind::Module)),
 335             hir::ModuleDef::Function(func) => {
 336                 let mut h = Highlight::new(HlTag::Symbol(SymbolKind::Function));
 337                 if let Some(item) = func.as_assoc_item(db) {
 338                     h |= HlMod::Associated;
 339                     match func.self_param(db) {
 340                         Some(sp) => {
 341                             if let hir::Access::Exclusive = sp.access(db) {
 342                                 h |= HlMod::Mutable;
 343                             }
 344                         }
 345                         None => h |= HlMod::Static,
 346                     }
 347
 348                     match item.container(db) {
 349                         hir::AssocItemContainer::Impl(i) => {
 350                             if i.trait_(db).is_some() {
 351                                 h |= HlMod::Trait;
 352                             }
 353                         }
 354                         hir::AssocItemContainer::Trait(_t) => {
 355                             h |= HlMod::Trait;
 356                         }
 357                     }
 358                 }
 359
 360                 if func.is_unsafe(db) {
 361                     h |= HlMod::Unsafe;
 362                 }
 363                 if func.is_async(db) {
 364                     h |= HlMod::Async;
 365                 }
 366
 367                 h
 368             }
 369             hir::ModuleDef::Adt(adt) => {
 370                 let h = match adt {
 371                     hir::Adt::Struct(_) => HlTag::Symbol(SymbolKind::Struct),
 372                     hir::Adt::Enum(_) => HlTag::Symbol(SymbolKind::Enum),
 373                     hir::Adt::Union(_) => HlTag::Symbol(SymbolKind::Union),
 374                 };
 375
 376                 Highlight::new(h)
 377             }
 378             hir::ModuleDef::Variant(_) => Highlight::new(HlTag::Symbol(SymbolKind::Variant)),
 379             hir::ModuleDef::Const(konst) => {
 380                 let mut h = Highlight::new(HlTag::Symbol(SymbolKind::Const));
 381
 382                 if let Some(item) = konst.as_assoc_item(db) {
 383                     h |= HlMod::Associated;
 384                     match item.container(db) {
 385                         hir::AssocItemContainer::Impl(i) => {
 386                             if i.trait_(db).is_some() {
 387                                 h |= HlMod::Trait;
 388                             }
 389                         }
 390                         hir::AssocItemContainer::Trait(_t) => {
 391                             h |= HlMod::Trait;
 392                         }
 393                     }
 394                 }
 395
 396                 h
 397             }
 398             hir::ModuleDef::Trait(_) => Highlight::new(HlTag::Symbol(SymbolKind::Trait)),
 399             hir::ModuleDef::TypeAlias(type_) => {
 400                 let mut h = Highlight::new(HlTag::Symbol(SymbolKind::TypeAlias));
 401
 402                 if let Some(item) = type_.as_assoc_item(db) {
 403                     h |= HlMod::Associated;
 404                     match item.container(db) {
 405                         hir::AssocItemContainer::Impl(i) => {
 406                             if i.trait_(db).is_some() {
 407                                 h |= HlMod::Trait;
 408                             }
 409                         }
 410                         hir::AssocItemContainer::Trait(_t) => {
 411                             h |= HlMod::Trait;
 412                         }
 413                     }
 414                 }
 415
 416                 h
 417             }
 418             hir::ModuleDef::BuiltinType(_) => Highlight::new(HlTag::BuiltinType),
 419             hir::ModuleDef::Static(s) => {
 420                 let mut h = Highlight::new(HlTag::Symbol(SymbolKind::Static));
 421
 422                 if s.is_mut(db) {
 423                     h |= HlMod::Mutable;
 424                     h |= HlMod::Unsafe;
 425                 }
 426
 427                 h
 428             }
 429         },
 430         Definition::SelfType(_) => Highlight::new(HlTag::Symbol(SymbolKind::Impl)),
 431         Definition::GenericParam(it) => match it {
 432             hir::GenericParam::TypeParam(_) => Highlight::new(HlTag::Symbol(SymbolKind::TypeParam)),
 433             hir::GenericParam::ConstParam(_) => {
 434                 Highlight::new(HlTag::Symbol(SymbolKind::ConstParam))
 435             }
 436             hir::GenericParam::LifetimeParam(_) => {
 437                 Highlight::new(HlTag::Symbol(SymbolKind::LifetimeParam))
 438             }
 439         },
 440         Definition::Local(local) => {
 441             let tag = if local.is_self(db) {
 442                 HlTag::Symbol(SymbolKind::SelfParam)
 443             } else if local.is_param(db) {
 444                 HlTag::Symbol(SymbolKind::ValueParam)
 445             } else {
 446                 HlTag::Symbol(SymbolKind::Local)
 447             };
 448             let mut h = Highlight::new(tag);
 449             let ty = local.ty(db);
 450             if local.is_mut(db) || ty.is_mutable_reference() {
 451                 h |= HlMod::Mutable;
 452             }
 453             if ty.as_callable(db).is_some() || ty.impls_fnonce(db) {
 454                 h |= HlMod::Callable;
 455             }
 456             h
 457         }
 458         Definition::Label(_) => Highlight::new(HlTag::Symbol(SymbolKind::Label)),
 459     };
 460
 461     let is_from_other_crate = def.module(db).map(hir::Module::krate) != krate;
 462     let is_builtin_type = matches!(def, Definition::ModuleDef(hir::ModuleDef::BuiltinType(_)));
 463     let is_public = def.visibility(db) == Some(hir::Visibility::Public);
 464
 465     match (is_from_other_crate, is_builtin_type, is_public) {
 466         (true, false, _) => h |= HlMod::Library,
 467         (false, _, true) => h |= HlMod::Public,
 468         _ => {}
 469     }
 470
 471     h
 472 }
 473
 474 fn highlight_method_call_by_name_ref(
 475     sema: &Semantics<RootDatabase>,
 476     krate: Option<hir::Crate>,
 477     name_ref: &ast::NameRef,
 478 ) -> Option<Highlight> {
 479     let mc = name_ref.syntax().parent().and_then(ast::MethodCallExpr::cast)?;
 480     highlight_method_call(sema, krate, &mc)
 481 }
 482
 483 fn highlight_method_call(
 484     sema: &Semantics<RootDatabase>,
 485     krate: Option<hir::Crate>,
 486     method_call: &ast::MethodCallExpr,
 487 ) -> Option<Highlight> {
 488     let func = sema.resolve_method_call(method_call)?;
 489
 490     let mut h = SymbolKind::Function.into();
 491     h |= HlMod::Associated;
 492
 493     if func.is_unsafe(sema.db) || sema.is_unsafe_method_call(method_call) {
 494         h |= HlMod::Unsafe;
 495     }
 496     if func.is_async(sema.db) {
 497         h |= HlMod::Async;
 498     }
 499     if func.as_assoc_item(sema.db).and_then(|it| it.containing_trait(sema.db)).is_some() {
 500         h |= HlMod::Trait;
 501     }
 502
 503     let is_from_other_crate = Some(func.module(sema.db).krate()) != krate;
 504     let is_public = func.visibility(sema.db) == hir::Visibility::Public;
 505
 506     if is_from_other_crate {
 507         h |= HlMod::Library;
 508     } else if is_public {
 509         h |= HlMod::Public;
 510     }
 511
 512     if let Some(self_param) = func.self_param(sema.db) {
 513         match self_param.access(sema.db) {
 514             hir::Access::Shared => (),
 515             hir::Access::Exclusive => h |= HlMod::Mutable,
 516             hir::Access::Owned => {
 517                 if let Some(receiver_ty) =
 518                     method_call.receiver().and_then(|it| sema.type_of_expr(&it))
 519                 {
 520                     if !receiver_ty.is_copy(sema.db) {
 521                         h |= HlMod::Consuming
 522                     }
 523                 }
 524             }
 525         }
 526     }
 527     Some(h)
 528 }
 529
 530 fn highlight_name_by_syntax(name: ast::Name) -> Highlight {
 531     let default = HlTag::UnresolvedReference;
 532
 533     let parent = match name.syntax().parent() {
 534         Some(it) => it,
 535         _ => return default.into(),
 536     };
 537
 538     let tag = match parent.kind() {
 539         STRUCT => SymbolKind::Struct,
 540         ENUM => SymbolKind::Enum,
 541         VARIANT => SymbolKind::Variant,
 542         UNION => SymbolKind::Union,
 543         TRAIT => SymbolKind::Trait,
 544         TYPE_ALIAS => SymbolKind::TypeAlias,
 545         TYPE_PARAM => SymbolKind::TypeParam,
 546         RECORD_FIELD => SymbolKind::Field,
 547         MODULE => SymbolKind::Module,
 548         FN => SymbolKind::Function,
 549         CONST => SymbolKind::Const,
 550         STATIC => SymbolKind::Static,
 551         IDENT_PAT => SymbolKind::Local,
 552         _ => return default.into(),
 553     };
 554
 555     tag.into()
 556 }
 557
 558 fn highlight_name_ref_by_syntax(
 559     name: ast::NameRef,
 560     sema: &Semantics<RootDatabase>,
 561     krate: Option<hir::Crate>,
 562 ) -> Highlight {
 563     let default = HlTag::UnresolvedReference;
 564
 565     let parent = match name.syntax().parent() {
 566         Some(it) => it,
 567         _ => return default.into(),
 568     };
 569
 570     match parent.kind() {
 571         METHOD_CALL_EXPR => ast::MethodCallExpr::cast(parent)
 572             .and_then(|it| highlight_method_call(sema, krate, &it))
 573             .unwrap_or_else(|| SymbolKind::Function.into()),
 574         FIELD_EXPR => {
 575             let h = HlTag::Symbol(SymbolKind::Field);
 576             let is_union = ast::FieldExpr::cast(parent)
 577                 .and_then(|field_expr| sema.resolve_field(&field_expr))
 578                 .map_or(false, |field| {
 579                     matches!(field.parent_def(sema.db), hir::VariantDef::Union(_))
 580                 });
 581             if is_union {
 582                 h | HlMod::Unsafe
 583             } else {
 584                 h.into()
 585             }
 586         }
 587         PATH_SEGMENT => {
 588             let path = match parent.parent().and_then(ast::Path::cast) {
 589                 Some(it) => it,
 590                 _ => return default.into(),
 591             };
 592             let expr = match path.syntax().parent().and_then(ast::PathExpr::cast) {
 593                 Some(it) => it,
 594                 _ => {
 595                     // within path, decide whether it is module or adt by checking for uppercase name
 596                     return if name.text().chars().next().unwrap_or_default().is_uppercase() {
 597                         SymbolKind::Struct
 598                     } else {
 599                         SymbolKind::Module
 600                     }
 601                     .into();
 602                 }
 603             };
 604             let parent = match expr.syntax().parent() {
 605                 Some(it) => it,
 606                 None => return default.into(),
 607             };
 608
 609             match parent.kind() {
 610                 CALL_EXPR => SymbolKind::Function.into(),
 611                 _ => if name.text().chars().next().unwrap_or_default().is_uppercase() {
 612                     SymbolKind::Struct
 613                 } else {
 614                     SymbolKind::Const
 615                 }
 616                 .into(),
 617             }
 618         }
 619         _ => default.into(),
 620     }
 621 }
 622
 623 fn is_consumed_lvalue(node: &SyntaxNode, local: &hir::Local, db: &RootDatabase) -> bool {
 624     // When lvalues are passed as arguments and they're not Copy, then mark them as Consuming.
 625     parents_match(node.clone().into(), &[PATH_SEGMENT, PATH, PATH_EXPR, ARG_LIST])
 626         && !local.ty(db).is_copy(db)
 627 }
 628
 629 /// Returns true if the parent nodes of `node` all match the `SyntaxKind`s in `kinds` exactly.
 630 fn parents_match(mut node: NodeOrToken<SyntaxNode, SyntaxToken>, mut kinds: &[SyntaxKind]) -> bool {
 631     while let (Some(parent), [kind, rest @ ..]) = (&node.parent(), kinds) {
 632         if parent.kind() != *kind {
 633             return false;
 634         }
 635
 636         // FIXME: Would be nice to get parent out of the match, but binding by-move and by-value
 637         // in the same pattern is unstable: rust-lang/rust#68354.
 638         node = node.parent().unwrap().into();
 639         kinds = rest;
 640     }
 641
 642     // Only true if we matched all expected kinds
 643     kinds.len() == 0
 644 }
 645
 646 #[inline]
 647 fn parent_matches<N: AstNode>(element: &SyntaxElement) -> bool {
 648     element.parent().map_or(false, |it| N::can_cast(it.kind()))
 649 }
 650
 651 fn is_child_of_impl(element: &SyntaxElement) -> bool {
 652     match element.parent() {
 653         Some(e) => e.kind() == IMPL,
 654         _ => false,
 655     }
 656 }