1 //! Computes color for a single element.
3 use hir::{AsAssocItem, HasVisibility, Semantics};
5 defs::{Definition, NameClass, NameRefClass},
6 RootDatabase, SymbolKind,
8 use rustc_hash::FxHashMap;
10 ast, AstNode, AstToken, NodeOrToken, SyntaxElement,
11 SyntaxKind::{self, *},
12 SyntaxNode, SyntaxToken, T,
16 syntax_highlighting::tags::{HlOperator, HlPunct},
17 Highlight, HlMod, HlTag,
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>)> {
28 let mut binding_hash = None;
29 let highlight: Highlight = match element.kind() {
31 bindings_shadow_count.clear();
35 // Highlight definitions depending on the "type" of the definition.
37 let name = element.into_node().and_then(ast::Name::cast).unwrap();
38 let name_kind = NameClass::classify(sema, &name);
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();
44 binding_hash = Some(calc_binding_hash(&name, *shadow_count))
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) {
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) {
69 None => highlight_name_by_syntax(name) | HlMod::Definition,
72 // Highlight references like the definitions they resolve to
73 NAME_REF if element.ancestors().any(|it| it.kind() == ATTR) => {
74 // even though we track whether we are in an attribute or not we still need this special case
75 // as otherwise we would emit unresolved references for name refs inside attributes
76 SymbolKind::Function.into()
79 let name_ref = element.into_node().and_then(ast::NameRef::cast).unwrap();
80 highlight_func_by_name_ref(sema, krate, &name_ref).unwrap_or_else(|| {
81 let is_self = name_ref.self_token().is_some();
82 let h = match NameRefClass::classify(sema, &name_ref) {
83 Some(name_kind) => match name_kind {
84 NameRefClass::ExternCrate(_) => SymbolKind::Module.into(),
85 NameRefClass::Definition(def) => {
86 if let Definition::Local(local) = &def {
87 if let Some(name) = local.name(db) {
89 bindings_shadow_count.entry(name.clone()).or_default();
90 binding_hash = Some(calc_binding_hash(&name, *shadow_count))
94 let mut h = highlight_def(db, krate, def);
97 Definition::Local(local)
98 if is_consumed_lvalue(
99 name_ref.syntax().clone().into(),
104 h |= HlMod::Consuming;
106 Definition::ModuleDef(hir::ModuleDef::Trait(trait_))
107 if trait_.is_unsafe(db) =>
109 if ast::Impl::for_trait_name_ref(&name_ref).is_some() {
113 Definition::Field(field) => {
114 if let Some(parent) = name_ref.syntax().parent() {
115 if matches!(parent.kind(), FIELD_EXPR | RECORD_PAT_FIELD) {
116 if let hir::VariantDef::Union(_) = field.parent_def(db)
128 NameRefClass::FieldShorthand { .. } => SymbolKind::Field.into(),
130 None if syntactic_name_ref_highlighting => {
131 highlight_name_ref_by_syntax(name_ref, sema, krate)
133 None => HlTag::UnresolvedReference.into(),
135 if h.tag == HlTag::Symbol(SymbolKind::Module) && is_self {
136 SymbolKind::SelfParam.into()
143 // Simple token-based highlighting
145 let comment = element.into_token().and_then(ast::Comment::cast)?;
146 let h = HlTag::Comment;
147 match comment.kind().doc {
148 Some(_) => h | HlMod::Documentation,
152 STRING | BYTE_STRING => HlTag::StringLiteral.into(),
153 ATTR => HlTag::Attribute.into(),
154 INT_NUMBER if element.ancestors().nth(1).map_or(false, |it| it.kind() == FIELD_EXPR) => {
155 SymbolKind::Field.into()
157 INT_NUMBER | FLOAT_NUMBER => HlTag::NumericLiteral.into(),
158 BYTE => HlTag::ByteLiteral.into(),
159 CHAR => HlTag::CharLiteral.into(),
160 QUESTION => HlTag::Operator(HlOperator::Other) | HlMod::ControlFlow,
162 let lifetime = element.into_node().and_then(ast::Lifetime::cast).unwrap();
164 match NameClass::classify_lifetime(sema, &lifetime) {
165 Some(NameClass::Definition(def)) => {
166 highlight_def(db, krate, def) | HlMod::Definition
168 None => match NameRefClass::classify_lifetime(sema, &lifetime) {
169 Some(NameRefClass::Definition(def)) => highlight_def(db, krate, def),
170 _ => SymbolKind::LifetimeParam.into(),
172 _ => Highlight::from(SymbolKind::LifetimeParam) | HlMod::Definition,
175 p if p.is_punct() => match p {
176 T![&] if parent_matches::<ast::BinExpr>(&element) => HlOperator::Bitwise.into(),
178 let h = HlTag::Operator(HlOperator::Other).into();
179 let is_unsafe = element
181 .and_then(ast::RefExpr::cast)
182 .map_or(false, |ref_expr| sema.is_unsafe_ref_expr(&ref_expr));
189 T![::] | T![->] | T![=>] | T![..] | T![=] | T![@] | T![.] => HlOperator::Other.into(),
190 T![!] if parent_matches::<ast::MacroCall>(&element) => SymbolKind::Macro.into(),
191 T![!] if parent_matches::<ast::NeverType>(&element) => HlTag::BuiltinType.into(),
192 T![!] if parent_matches::<ast::PrefixExpr>(&element) => HlOperator::Logical.into(),
193 T![*] if parent_matches::<ast::PtrType>(&element) => HlTag::Keyword.into(),
194 T![*] if parent_matches::<ast::PrefixExpr>(&element) => {
195 let prefix_expr = element.parent().and_then(ast::PrefixExpr::cast)?;
197 let expr = prefix_expr.expr()?;
198 let ty = sema.type_of_expr(&expr)?;
200 HlTag::Operator(HlOperator::Other) | HlMod::Unsafe
201 } else if let Some(ast::PrefixOp::Deref) = prefix_expr.op_kind() {
202 HlOperator::Other.into()
204 HlPunct::Other.into()
207 T![-] if parent_matches::<ast::PrefixExpr>(&element) => {
208 let prefix_expr = element.parent().and_then(ast::PrefixExpr::cast)?;
210 let expr = prefix_expr.expr()?;
212 ast::Expr::Literal(_) => HlTag::NumericLiteral,
213 _ => HlTag::Operator(HlOperator::Other),
217 _ if parent_matches::<ast::PrefixExpr>(&element) => HlOperator::Other.into(),
218 T![+] | T![-] | T![*] | T![/] | T![+=] | T![-=] | T![*=] | T![/=]
219 if parent_matches::<ast::BinExpr>(&element) =>
221 HlOperator::Arithmetic.into()
223 T![|] | T![&] | T![!] | T![^] | T![|=] | T![&=] | T![^=]
224 if parent_matches::<ast::BinExpr>(&element) =>
226 HlOperator::Bitwise.into()
228 T![&&] | T![||] if parent_matches::<ast::BinExpr>(&element) => {
229 HlOperator::Logical.into()
231 T![>] | T![<] | T![==] | T![>=] | T![<=] | T![!=]
232 if parent_matches::<ast::BinExpr>(&element) =>
234 HlOperator::Comparison.into()
236 _ if parent_matches::<ast::BinExpr>(&element) => HlOperator::Other.into(),
237 _ if parent_matches::<ast::RangeExpr>(&element) => HlOperator::Other.into(),
238 _ if parent_matches::<ast::RangePat>(&element) => HlOperator::Other.into(),
239 _ if parent_matches::<ast::RestPat>(&element) => HlOperator::Other.into(),
240 _ if parent_matches::<ast::Attr>(&element) => HlTag::Attribute.into(),
242 T!['['] | T![']'] => HlPunct::Bracket,
243 T!['{'] | T!['}'] => HlPunct::Brace,
244 T!['('] | T![')'] => HlPunct::Parenthesis,
245 T![<] | T![>] => HlPunct::Angle,
246 T![,] => HlPunct::Comma,
247 T![:] => HlPunct::Colon,
248 T![;] => HlPunct::Semi,
249 T![.] => HlPunct::Dot,
255 k if k.is_keyword() => {
256 let h = Highlight::new(HlTag::Keyword);
258 T![await] => h | HlMod::Async | HlMod::ControlFlow,
268 | T![yield] => h | HlMod::ControlFlow,
269 T![for] if !is_child_of_impl(&element) => h | HlMod::ControlFlow,
270 T![unsafe] => h | HlMod::Unsafe,
271 T![true] | T![false] => HlTag::BoolLiteral.into(),
272 // self is handled as either a Name or NameRef already
273 T![self] => return None,
276 .and_then(ast::IdentPat::cast)
277 .and_then(|ident_pat| {
278 if sema.is_unsafe_ident_pat(&ident_pat) {
284 .map(|modifier| h | modifier)
286 T![async] => h | HlMod::Async,
294 return Some((highlight, binding_hash));
296 fn calc_binding_hash(name: &hir::Name, shadow_count: u32) -> u64 {
297 fn hash<T: std::hash::Hash + std::fmt::Debug>(x: T) -> u64 {
298 use std::{collections::hash_map::DefaultHasher, hash::Hasher};
300 let mut hasher = DefaultHasher::new();
305 hash((name, shadow_count))
308 fn highlight_def(db: &RootDatabase, krate: Option<hir::Crate>, def: Definition) -> Highlight {
309 let mut h = match def {
310 Definition::Macro(_) => Highlight::new(HlTag::Symbol(SymbolKind::Macro)),
311 Definition::Field(_) => Highlight::new(HlTag::Symbol(SymbolKind::Field)),
312 Definition::ModuleDef(def) => match def {
313 hir::ModuleDef::Module(_) => Highlight::new(HlTag::Symbol(SymbolKind::Module)),
314 hir::ModuleDef::Function(func) => {
315 let mut h = Highlight::new(HlTag::Symbol(SymbolKind::Function));
316 if let Some(item) = func.as_assoc_item(db) {
317 h |= HlMod::Associated;
318 match func.self_param(db) {
320 if let hir::Access::Exclusive = sp.access(db) {
324 None => h |= HlMod::Static,
327 match item.container(db) {
328 hir::AssocItemContainer::Impl(i) => {
329 if i.trait_(db).is_some() {
333 hir::AssocItemContainer::Trait(_t) => {
339 if func.is_unsafe(db) {
342 if func.is_async(db) {
348 hir::ModuleDef::Adt(adt) => {
350 hir::Adt::Struct(_) => HlTag::Symbol(SymbolKind::Struct),
351 hir::Adt::Enum(_) => HlTag::Symbol(SymbolKind::Enum),
352 hir::Adt::Union(_) => HlTag::Symbol(SymbolKind::Union),
357 hir::ModuleDef::Variant(_) => Highlight::new(HlTag::Symbol(SymbolKind::Variant)),
358 hir::ModuleDef::Const(konst) => {
359 let mut h = Highlight::new(HlTag::Symbol(SymbolKind::Const));
361 if let Some(item) = konst.as_assoc_item(db) {
362 h |= HlMod::Associated;
363 match item.container(db) {
364 hir::AssocItemContainer::Impl(i) => {
365 if i.trait_(db).is_some() {
369 hir::AssocItemContainer::Trait(_t) => {
377 hir::ModuleDef::Trait(_) => Highlight::new(HlTag::Symbol(SymbolKind::Trait)),
378 hir::ModuleDef::TypeAlias(type_) => {
379 let mut h = Highlight::new(HlTag::Symbol(SymbolKind::TypeAlias));
381 if let Some(item) = type_.as_assoc_item(db) {
382 h |= HlMod::Associated;
383 match item.container(db) {
384 hir::AssocItemContainer::Impl(i) => {
385 if i.trait_(db).is_some() {
389 hir::AssocItemContainer::Trait(_t) => {
397 hir::ModuleDef::BuiltinType(_) => Highlight::new(HlTag::BuiltinType),
398 hir::ModuleDef::Static(s) => {
399 let mut h = Highlight::new(HlTag::Symbol(SymbolKind::Static));
409 Definition::SelfType(_) => Highlight::new(HlTag::Symbol(SymbolKind::Impl)),
410 Definition::GenericParam(it) => match it {
411 hir::GenericParam::TypeParam(_) => Highlight::new(HlTag::Symbol(SymbolKind::TypeParam)),
412 hir::GenericParam::ConstParam(_) => {
413 Highlight::new(HlTag::Symbol(SymbolKind::ConstParam))
415 hir::GenericParam::LifetimeParam(_) => {
416 Highlight::new(HlTag::Symbol(SymbolKind::LifetimeParam))
419 Definition::Local(local) => {
420 let tag = if local.is_self(db) {
421 HlTag::Symbol(SymbolKind::SelfParam)
422 } else if local.is_param(db) {
423 HlTag::Symbol(SymbolKind::ValueParam)
425 HlTag::Symbol(SymbolKind::Local)
427 let mut h = Highlight::new(tag);
428 let ty = local.ty(db);
429 if local.is_mut(db) || ty.is_mutable_reference() {
432 if ty.as_callable(db).is_some() || ty.impls_fnonce(db) {
433 h |= HlMod::Callable;
437 Definition::Label(_) => Highlight::new(HlTag::Symbol(SymbolKind::Label)),
440 let is_from_other_crate = def.module(db).map(hir::Module::krate) != krate;
441 let is_builtin_type = matches!(def, Definition::ModuleDef(hir::ModuleDef::BuiltinType(_)));
442 let is_public = def.visibility(db) == Some(hir::Visibility::Public);
444 match (is_from_other_crate, is_builtin_type, is_public) {
445 (true, false, _) => h |= HlMod::Library,
446 (false, _, true) => h |= HlMod::Public,
453 fn highlight_func_by_name_ref(
454 sema: &Semantics<RootDatabase>,
455 krate: Option<hir::Crate>,
456 name_ref: &ast::NameRef,
457 ) -> Option<Highlight> {
458 let mc = name_ref.syntax().parent().and_then(ast::MethodCallExpr::cast)?;
459 highlight_method_call(sema, krate, &mc)
462 fn highlight_method_call(
463 sema: &Semantics<RootDatabase>,
464 krate: Option<hir::Crate>,
465 method_call: &ast::MethodCallExpr,
466 ) -> Option<Highlight> {
467 let func = sema.resolve_method_call(method_call)?;
469 let mut h = SymbolKind::Function.into();
470 h |= HlMod::Associated;
472 if func.is_unsafe(sema.db) || sema.is_unsafe_method_call(method_call) {
475 if func.is_async(sema.db) {
478 if func.as_assoc_item(sema.db).and_then(|it| it.containing_trait(sema.db)).is_some() {
482 let is_from_other_crate = Some(func.module(sema.db).krate()) != krate;
483 let is_public = func.visibility(sema.db) == hir::Visibility::Public;
485 if is_from_other_crate {
487 } else if is_public {
491 if let Some(self_param) = func.self_param(sema.db) {
492 match self_param.access(sema.db) {
493 hir::Access::Shared => (),
494 hir::Access::Exclusive => h |= HlMod::Mutable,
495 hir::Access::Owned => {
496 if let Some(receiver_ty) =
497 method_call.receiver().and_then(|it| sema.type_of_expr(&it))
499 if !receiver_ty.is_copy(sema.db) {
500 h |= HlMod::Consuming
509 fn highlight_name_by_syntax(name: ast::Name) -> Highlight {
510 let default = HlTag::UnresolvedReference;
512 let parent = match name.syntax().parent() {
514 _ => return default.into(),
517 let tag = match parent.kind() {
518 STRUCT => SymbolKind::Struct,
519 ENUM => SymbolKind::Enum,
520 VARIANT => SymbolKind::Variant,
521 UNION => SymbolKind::Union,
522 TRAIT => SymbolKind::Trait,
523 TYPE_ALIAS => SymbolKind::TypeAlias,
524 TYPE_PARAM => SymbolKind::TypeParam,
525 RECORD_FIELD => SymbolKind::Field,
526 MODULE => SymbolKind::Module,
527 FN => SymbolKind::Function,
528 CONST => SymbolKind::Const,
529 STATIC => SymbolKind::Static,
530 IDENT_PAT => SymbolKind::Local,
531 _ => return default.into(),
537 fn highlight_name_ref_by_syntax(
539 sema: &Semantics<RootDatabase>,
540 krate: Option<hir::Crate>,
542 let default = HlTag::UnresolvedReference;
544 let parent = match name.syntax().parent() {
546 _ => return default.into(),
549 match parent.kind() {
550 METHOD_CALL_EXPR => ast::MethodCallExpr::cast(parent)
551 .and_then(|it| highlight_method_call(sema, krate, &it))
552 .unwrap_or_else(|| SymbolKind::Function.into()),
554 let h = HlTag::Symbol(SymbolKind::Field);
555 let is_union = ast::FieldExpr::cast(parent)
556 .and_then(|field_expr| sema.resolve_field(&field_expr))
557 .map_or(false, |field| {
558 matches!(field.parent_def(sema.db), hir::VariantDef::Union(_))
567 let path = match parent.parent().and_then(ast::Path::cast) {
569 _ => return default.into(),
571 let expr = match path.syntax().parent().and_then(ast::PathExpr::cast) {
574 // within path, decide whether it is module or adt by checking for uppercase name
575 return if name.text().chars().next().unwrap_or_default().is_uppercase() {
583 let parent = match expr.syntax().parent() {
585 None => return default.into(),
588 match parent.kind() {
589 CALL_EXPR => SymbolKind::Function.into(),
590 _ => if name.text().chars().next().unwrap_or_default().is_uppercase() {
602 fn is_consumed_lvalue(
603 node: NodeOrToken<SyntaxNode, SyntaxToken>,
607 // When lvalues are passed as arguments and they're not Copy, then mark them as Consuming.
608 parents_match(node, &[PATH_SEGMENT, PATH, PATH_EXPR, ARG_LIST]) && !local.ty(db).is_copy(db)
611 /// Returns true if the parent nodes of `node` all match the `SyntaxKind`s in `kinds` exactly.
612 fn parents_match(mut node: NodeOrToken<SyntaxNode, SyntaxToken>, mut kinds: &[SyntaxKind]) -> bool {
613 while let (Some(parent), [kind, rest @ ..]) = (&node.parent(), kinds) {
614 if parent.kind() != *kind {
618 // FIXME: Would be nice to get parent out of the match, but binding by-move and by-value
619 // in the same pattern is unstable: rust-lang/rust#68354.
620 node = node.parent().unwrap().into();
624 // Only true if we matched all expected kinds
629 fn parent_matches<N: AstNode>(element: &SyntaxElement) -> bool {
630 element.parent().map_or(false, |it| N::can_cast(it.kind()))
633 fn is_child_of_impl(element: &SyntaxElement) -> bool {
634 match element.parent() {
635 Some(e) => e.kind() == IMPL,