1 //! Computes color for a single element.
3 use hir::{AsAssocItem, HasVisibility, Semantics};
5 defs::{Definition, NameClass, NameRefClass},
7 RootDatabase, SymbolKind,
9 use rustc_hash::FxHashMap;
11 ast, match_ast, AstNode, AstToken, NodeOrToken,
12 SyntaxKind::{self, *},
13 SyntaxNode, SyntaxToken, T,
17 syntax_highlighting::tags::{HlOperator, HlPunct},
18 Highlight, HlMod, HlTag,
22 sema: &Semantics<RootDatabase>,
23 krate: Option<hir::Crate>,
25 ) -> Option<Highlight> {
26 if let Some(comment) = ast::Comment::cast(token.clone()) {
27 let h = HlTag::Comment;
28 return Some(match comment.kind().doc {
29 Some(_) => h | HlMod::Documentation,
34 let highlight: Highlight = match token.kind() {
35 STRING | BYTE_STRING => HlTag::StringLiteral.into(),
36 INT_NUMBER if token.ancestors().nth(1).map(|it| it.kind()) == Some(FIELD_EXPR) => {
37 SymbolKind::Field.into()
39 INT_NUMBER | FLOAT_NUMBER => HlTag::NumericLiteral.into(),
40 BYTE => HlTag::ByteLiteral.into(),
41 CHAR => HlTag::CharLiteral.into(),
43 let tt = ast::TokenTree::cast(token.parent()?)?;
44 let ident = ast::Ident::cast(token)?;
45 // from this point on we are inside a token tree, this only happens for identifiers
46 // that were not mapped down into macro invocations
48 let attr = tt.parent_meta()?.parent_attr()?;
49 let res = sema.resolve_derive_ident(&attr, &ident)?;
50 Some(highlight_def(sema, krate, Definition::from(res)))
52 .unwrap_or_else(|| HlTag::None.into())
54 p if p.is_punct() => punctuation(sema, token, p),
55 k if k.is_keyword() => keyword(sema, token, k)?,
62 sema: &Semantics<RootDatabase>,
63 krate: Option<hir::Crate>,
64 bindings_shadow_count: &mut FxHashMap<hir::Name, u32>,
65 syntactic_name_ref_highlighting: bool,
67 ) -> Option<(Highlight, Option<u64>)> {
68 let mut binding_hash = None;
69 let highlight = match_ast! {
71 ast::NameRef(name_ref) => {
75 bindings_shadow_count,
77 syntactic_name_ref_highlighting,
82 highlight_name(sema, bindings_shadow_count, &mut binding_hash, krate, name)
84 ast::Lifetime(lifetime) => {
85 match NameClass::classify_lifetime(sema, &lifetime) {
86 Some(NameClass::Definition(def)) => {
87 highlight_def(sema, krate, def) | HlMod::Definition
89 None => match NameRefClass::classify_lifetime(sema, &lifetime) {
90 Some(NameRefClass::Definition(def)) => highlight_def(sema, krate, def),
91 _ => SymbolKind::LifetimeParam.into(),
93 _ => Highlight::from(SymbolKind::LifetimeParam) | HlMod::Definition,
97 bindings_shadow_count.clear();
101 if [FN, CONST, STATIC].contains(&node.kind()) {
102 bindings_shadow_count.clear();
108 Some((highlight, binding_hash))
111 fn punctuation(sema: &Semantics<RootDatabase>, token: SyntaxToken, kind: SyntaxKind) -> Highlight {
112 let parent = token.parent();
113 let parent_kind = parent.as_ref().map_or(EOF, SyntaxNode::kind);
114 match (kind, parent_kind) {
115 (T![?], _) => HlTag::Operator(HlOperator::Other) | HlMod::ControlFlow,
116 (T![&], BIN_EXPR) => HlOperator::Bitwise.into(),
118 let h = HlTag::Operator(HlOperator::Other).into();
119 let is_unsafe = parent
120 .and_then(ast::RefExpr::cast)
121 .map(|ref_expr| sema.is_unsafe_ref_expr(&ref_expr));
122 if let Some(true) = is_unsafe {
128 (T![::] | T![->] | T![=>] | T![..] | T![=] | T![@] | T![.], _) => HlOperator::Other.into(),
129 (T![!], MACRO_CALL) => HlPunct::MacroBang.into(),
130 (T![!], NEVER_TYPE) => HlTag::BuiltinType.into(),
131 (T![!], PREFIX_EXPR) => HlOperator::Logical.into(),
132 (T![*], PTR_TYPE) => HlTag::Keyword.into(),
133 (T![*], PREFIX_EXPR) => {
134 let is_raw_ptr = (|| {
135 let prefix_expr = parent.and_then(ast::PrefixExpr::cast)?;
136 let expr = prefix_expr.expr()?;
137 sema.type_of_expr(&expr)?.original.is_raw_ptr().then(|| ())
139 if let Some(()) = is_raw_ptr {
140 HlTag::Operator(HlOperator::Other) | HlMod::Unsafe
142 HlOperator::Other.into()
145 (T![-], PREFIX_EXPR) => {
146 let prefix_expr = parent.and_then(ast::PrefixExpr::cast).and_then(|e| e.expr());
148 Some(ast::Expr::Literal(_)) => HlTag::NumericLiteral,
149 _ => HlTag::Operator(HlOperator::Other),
153 (T![+] | T![-] | T![*] | T![/], BIN_EXPR) => HlOperator::Arithmetic.into(),
154 (T![+=] | T![-=] | T![*=] | T![/=], BIN_EXPR) => {
155 Highlight::from(HlOperator::Arithmetic) | HlMod::Mutable
157 (T![|] | T![&] | T![!] | T![^], BIN_EXPR) => HlOperator::Bitwise.into(),
158 (T![|=] | T![&=] | T![^=], BIN_EXPR) => {
159 Highlight::from(HlOperator::Bitwise) | HlMod::Mutable
161 (T![&&] | T![||], BIN_EXPR) => HlOperator::Logical.into(),
162 (T![>] | T![<] | T![==] | T![>=] | T![<=] | T![!=], BIN_EXPR) => {
163 HlOperator::Comparison.into()
165 (_, PREFIX_EXPR | BIN_EXPR | RANGE_EXPR | RANGE_PAT | REST_PAT) => HlOperator::Other.into(),
166 (_, ATTR) => HlTag::AttributeBracket.into(),
167 (kind, _) => match kind {
168 T!['['] | T![']'] => HlPunct::Bracket,
169 T!['{'] | T!['}'] => HlPunct::Brace,
170 T!['('] | T![')'] => HlPunct::Parenthesis,
171 T![<] | T![>] => HlPunct::Angle,
172 T![,] => HlPunct::Comma,
173 T![:] => HlPunct::Colon,
174 T![;] => HlPunct::Semi,
175 T![.] => HlPunct::Dot,
183 sema: &Semantics<RootDatabase>,
186 ) -> Option<Highlight> {
187 let h = Highlight::new(HlTag::Keyword);
189 T![await] => h | HlMod::Async | HlMod::ControlFlow,
190 T![async] => h | HlMod::Async,
200 | T![yield] => h | HlMod::ControlFlow,
201 T![for] if parent_matches::<ast::ForExpr>(&token) => h | HlMod::ControlFlow,
202 T![unsafe] => h | HlMod::Unsafe,
203 T![true] | T![false] => HlTag::BoolLiteral.into(),
204 // crate is handled just as a token if it's in an `extern crate`
205 T![crate] if parent_matches::<ast::ExternCrate>(&token) => h,
206 // self, crate and super are handled as either a Name or NameRef already, unless they
207 // are inside unmapped token trees
208 T![self] | T![crate] | T![super] if parent_matches::<ast::NameRef>(&token) => return None,
209 T![self] if parent_matches::<ast::Name>(&token) => return None,
210 T![ref] => match token.parent().and_then(ast::IdentPat::cast) {
211 Some(ident) if sema.is_unsafe_ident_pat(&ident) => h | HlMod::Unsafe,
219 fn highlight_name_ref(
220 sema: &Semantics<RootDatabase>,
221 krate: Option<hir::Crate>,
222 bindings_shadow_count: &mut FxHashMap<hir::Name, u32>,
223 binding_hash: &mut Option<u64>,
224 syntactic_name_ref_highlighting: bool,
225 name_ref: ast::NameRef,
228 if let Some(res) = highlight_method_call_by_name_ref(sema, krate, &name_ref) {
232 let name_class = match NameRefClass::classify(sema, &name_ref) {
233 Some(name_kind) => name_kind,
234 None if syntactic_name_ref_highlighting => {
235 return highlight_name_ref_by_syntax(name_ref, sema, krate)
237 // FIXME: This is required for helper attributes used by proc-macros, as those do not map down
238 // to anything when used.
239 // We can fix this for derive attributes since derive helpers are recorded, but not for
240 // general attributes.
241 None if name_ref.syntax().ancestors().any(|it| it.kind() == ATTR) => {
242 return HlTag::Symbol(SymbolKind::Attribute).into();
244 None => return HlTag::UnresolvedReference.into(),
246 let mut h = match name_class {
247 NameRefClass::Definition(def) => {
248 if let Definition::Local(local) = &def {
249 if let Some(name) = local.name(db) {
250 let shadow_count = bindings_shadow_count.entry(name.clone()).or_default();
251 *binding_hash = Some(calc_binding_hash(&name, *shadow_count))
255 let mut h = highlight_def(sema, krate, def);
258 Definition::Local(local) if is_consumed_lvalue(name_ref.syntax(), &local, db) => {
259 h |= HlMod::Consuming;
261 Definition::Trait(trait_) if trait_.is_unsafe(db) => {
262 if ast::Impl::for_trait_name_ref(&name_ref)
263 .map_or(false, |impl_| impl_.unsafe_token().is_some())
268 Definition::Field(field) => {
269 if let Some(parent) = name_ref.syntax().parent() {
270 if matches!(parent.kind(), FIELD_EXPR | RECORD_PAT_FIELD) {
271 if let hir::VariantDef::Union(_) = field.parent_def(db) {
282 NameRefClass::FieldShorthand { .. } => SymbolKind::Field.into(),
284 if name_ref.self_token().is_some() {
285 h.tag = HlTag::Symbol(SymbolKind::SelfParam);
287 if name_ref.crate_token().is_some() || name_ref.super_token().is_some() {
288 h.tag = HlTag::Keyword;
294 sema: &Semantics<RootDatabase>,
295 bindings_shadow_count: &mut FxHashMap<hir::Name, u32>,
296 binding_hash: &mut Option<u64>,
297 krate: Option<hir::Crate>,
300 let name_kind = NameClass::classify(sema, &name);
301 if let Some(NameClass::Definition(Definition::Local(local))) = &name_kind {
302 if let Some(name) = local.name(sema.db) {
303 let shadow_count = bindings_shadow_count.entry(name.clone()).or_default();
305 *binding_hash = Some(calc_binding_hash(&name, *shadow_count))
309 Some(NameClass::Definition(def)) => {
310 let mut h = highlight_def(sema, krate, def) | HlMod::Definition;
311 if let Definition::Trait(trait_) = &def {
312 if trait_.is_unsafe(sema.db) {
318 Some(NameClass::ConstReference(def)) => highlight_def(sema, krate, def),
319 Some(NameClass::PatFieldShorthand { field_ref, .. }) => {
320 let mut h = HlTag::Symbol(SymbolKind::Field).into();
321 if let hir::VariantDef::Union(_) = field_ref.parent_def(sema.db) {
326 None => highlight_name_by_syntax(name) | HlMod::Definition,
330 fn calc_binding_hash(name: &hir::Name, shadow_count: u32) -> u64 {
331 fn hash<T: std::hash::Hash + std::fmt::Debug>(x: T) -> u64 {
332 use std::{collections::hash_map::DefaultHasher, hash::Hasher};
334 let mut hasher = DefaultHasher::new();
339 hash((name, shadow_count))
343 sema: &Semantics<RootDatabase>,
344 krate: Option<hir::Crate>,
348 let mut h = match def {
349 Definition::Macro(m) => Highlight::new(HlTag::Symbol(m.kind().into())),
350 Definition::Field(_) => Highlight::new(HlTag::Symbol(SymbolKind::Field)),
351 Definition::Module(module) => {
352 let mut h = Highlight::new(HlTag::Symbol(SymbolKind::Module));
353 if module.parent(db).is_none() {
354 h |= HlMod::CrateRoot
358 Definition::Function(func) => {
359 let mut h = Highlight::new(HlTag::Symbol(SymbolKind::Function));
360 if let Some(item) = func.as_assoc_item(db) {
361 h |= HlMod::Associated;
362 match func.self_param(db) {
363 Some(sp) => match sp.access(db) {
364 hir::Access::Exclusive => {
366 h |= HlMod::Reference;
368 hir::Access::Shared => h |= HlMod::Reference,
369 hir::Access::Owned => h |= HlMod::Consuming,
371 None => h |= HlMod::Static,
374 match item.container(db) {
375 hir::AssocItemContainer::Impl(i) => {
376 if i.trait_(db).is_some() {
380 hir::AssocItemContainer::Trait(_t) => {
386 if func.is_unsafe(db) {
389 if func.is_async(db) {
395 Definition::Adt(adt) => {
397 hir::Adt::Struct(_) => HlTag::Symbol(SymbolKind::Struct),
398 hir::Adt::Enum(_) => HlTag::Symbol(SymbolKind::Enum),
399 hir::Adt::Union(_) => HlTag::Symbol(SymbolKind::Union),
404 Definition::Variant(_) => Highlight::new(HlTag::Symbol(SymbolKind::Variant)),
405 Definition::Const(konst) => {
406 let mut h = Highlight::new(HlTag::Symbol(SymbolKind::Const));
408 if let Some(item) = konst.as_assoc_item(db) {
409 h |= HlMod::Associated;
410 match item.container(db) {
411 hir::AssocItemContainer::Impl(i) => {
412 if i.trait_(db).is_some() {
416 hir::AssocItemContainer::Trait(_t) => {
424 Definition::Trait(_) => Highlight::new(HlTag::Symbol(SymbolKind::Trait)),
425 Definition::TypeAlias(type_) => {
426 let mut h = Highlight::new(HlTag::Symbol(SymbolKind::TypeAlias));
428 if let Some(item) = type_.as_assoc_item(db) {
429 h |= HlMod::Associated;
430 match item.container(db) {
431 hir::AssocItemContainer::Impl(i) => {
432 if i.trait_(db).is_some() {
436 hir::AssocItemContainer::Trait(_t) => {
444 Definition::BuiltinType(_) => Highlight::new(HlTag::BuiltinType),
445 Definition::Static(s) => {
446 let mut h = Highlight::new(HlTag::Symbol(SymbolKind::Static));
455 Definition::SelfType(_) => Highlight::new(HlTag::Symbol(SymbolKind::Impl)),
456 Definition::GenericParam(it) => match it {
457 hir::GenericParam::TypeParam(_) => Highlight::new(HlTag::Symbol(SymbolKind::TypeParam)),
458 hir::GenericParam::ConstParam(_) => {
459 Highlight::new(HlTag::Symbol(SymbolKind::ConstParam))
461 hir::GenericParam::LifetimeParam(_) => {
462 Highlight::new(HlTag::Symbol(SymbolKind::LifetimeParam))
465 Definition::Local(local) => {
466 let tag = if local.is_self(db) {
467 HlTag::Symbol(SymbolKind::SelfParam)
468 } else if local.is_param(db) {
469 HlTag::Symbol(SymbolKind::ValueParam)
471 HlTag::Symbol(SymbolKind::Local)
473 let mut h = Highlight::new(tag);
474 let ty = local.ty(db);
475 if local.is_mut(db) || ty.is_mutable_reference() {
478 if local.is_ref(db) || ty.is_reference() {
479 h |= HlMod::Reference;
481 if ty.as_callable(db).is_some() || ty.impls_fnonce(db) {
482 h |= HlMod::Callable;
486 Definition::Label(_) => Highlight::new(HlTag::Symbol(SymbolKind::Label)),
487 Definition::BuiltinAttr(_) => Highlight::new(HlTag::Symbol(SymbolKind::BuiltinAttr)),
488 Definition::ToolModule(_) => Highlight::new(HlTag::Symbol(SymbolKind::ToolModule)),
491 let famous_defs = FamousDefs(sema, krate);
492 let def_crate = def.module(db).map(hir::Module::krate).or_else(|| match def {
493 Definition::Module(module) => Some(module.krate()),
496 let is_from_other_crate = def_crate != krate;
497 let is_from_builtin_crate =
498 def_crate.map_or(false, |def_crate| famous_defs.builtin_crates().any(|it| def_crate == it));
499 let is_builtin_type = matches!(def, Definition::BuiltinType(_));
500 let is_public = def.visibility(db) == Some(hir::Visibility::Public);
502 match (is_from_other_crate, is_builtin_type, is_public) {
503 (true, false, _) => h |= HlMod::Library,
504 (false, _, true) => h |= HlMod::Public,
508 if is_from_builtin_crate {
509 h |= HlMod::DefaultLibrary;
515 fn highlight_method_call_by_name_ref(
516 sema: &Semantics<RootDatabase>,
517 krate: Option<hir::Crate>,
518 name_ref: &ast::NameRef,
519 ) -> Option<Highlight> {
520 let mc = name_ref.syntax().parent().and_then(ast::MethodCallExpr::cast)?;
521 highlight_method_call(sema, krate, &mc)
524 fn highlight_method_call(
525 sema: &Semantics<RootDatabase>,
526 krate: Option<hir::Crate>,
527 method_call: &ast::MethodCallExpr,
528 ) -> Option<Highlight> {
529 let func = sema.resolve_method_call(method_call)?;
531 let mut h = SymbolKind::Function.into();
532 h |= HlMod::Associated;
534 if func.is_unsafe(sema.db) || sema.is_unsafe_method_call(method_call) {
537 if func.is_async(sema.db) {
540 if func.as_assoc_item(sema.db).and_then(|it| it.containing_trait(sema.db)).is_some() {
544 let famous_defs = FamousDefs(sema, krate);
545 let def_crate = func.module(sema.db).krate();
546 let is_from_other_crate = Some(def_crate) != krate;
547 let is_from_builtin_crate = famous_defs.builtin_crates().any(|it| def_crate == it);
548 let is_public = func.visibility(sema.db) == hir::Visibility::Public;
550 if is_from_other_crate {
552 } else if is_public {
556 if is_from_builtin_crate {
557 h |= HlMod::DefaultLibrary;
560 if let Some(self_param) = func.self_param(sema.db) {
561 match self_param.access(sema.db) {
562 hir::Access::Shared => h |= HlMod::Reference,
563 hir::Access::Exclusive => {
565 h |= HlMod::Reference;
567 hir::Access::Owned => {
568 if let Some(receiver_ty) =
569 method_call.receiver().and_then(|it| sema.type_of_expr(&it))
571 if !receiver_ty.adjusted().is_copy(sema.db) {
572 h |= HlMod::Consuming
581 fn highlight_name_by_syntax(name: ast::Name) -> Highlight {
582 let default = HlTag::UnresolvedReference;
584 let parent = match name.syntax().parent() {
586 _ => return default.into(),
589 let tag = match parent.kind() {
590 STRUCT => SymbolKind::Struct,
591 ENUM => SymbolKind::Enum,
592 VARIANT => SymbolKind::Variant,
593 UNION => SymbolKind::Union,
594 TRAIT => SymbolKind::Trait,
595 TYPE_ALIAS => SymbolKind::TypeAlias,
596 TYPE_PARAM => SymbolKind::TypeParam,
597 RECORD_FIELD => SymbolKind::Field,
598 MODULE => SymbolKind::Module,
599 FN => SymbolKind::Function,
600 CONST => SymbolKind::Const,
601 STATIC => SymbolKind::Static,
602 IDENT_PAT => SymbolKind::Local,
603 _ => return default.into(),
609 fn highlight_name_ref_by_syntax(
611 sema: &Semantics<RootDatabase>,
612 krate: Option<hir::Crate>,
614 let default = HlTag::UnresolvedReference;
616 let parent = match name.syntax().parent() {
618 _ => return default.into(),
621 match parent.kind() {
622 METHOD_CALL_EXPR => ast::MethodCallExpr::cast(parent)
623 .and_then(|it| highlight_method_call(sema, krate, &it))
624 .unwrap_or_else(|| SymbolKind::Function.into()),
626 let h = HlTag::Symbol(SymbolKind::Field);
627 let is_union = ast::FieldExpr::cast(parent)
628 .and_then(|field_expr| sema.resolve_field(&field_expr))
629 .map_or(false, |field| {
630 matches!(field.parent_def(sema.db), hir::VariantDef::Union(_))
639 let name_based_fallback = || {
640 if name.text().chars().next().unwrap_or_default().is_uppercase() {
641 SymbolKind::Struct.into()
643 SymbolKind::Module.into()
646 let path = match parent.parent().and_then(ast::Path::cast) {
648 _ => return name_based_fallback(),
650 let expr = match path.syntax().parent() {
651 Some(parent) => match_ast! {
653 ast::PathExpr(path) => path,
654 ast::MacroCall(_) => return SymbolKind::Macro.into(),
655 _ => return name_based_fallback(),
658 // within path, decide whether it is module or adt by checking for uppercase name
659 None => return name_based_fallback(),
661 let parent = match expr.syntax().parent() {
663 None => return default.into(),
666 match parent.kind() {
667 CALL_EXPR => SymbolKind::Function.into(),
668 _ => if name.text().chars().next().unwrap_or_default().is_uppercase() {
680 fn is_consumed_lvalue(node: &SyntaxNode, local: &hir::Local, db: &RootDatabase) -> bool {
681 // When lvalues are passed as arguments and they're not Copy, then mark them as Consuming.
682 parents_match(node.clone().into(), &[PATH_SEGMENT, PATH, PATH_EXPR, ARG_LIST])
683 && !local.ty(db).is_copy(db)
686 /// Returns true if the parent nodes of `node` all match the `SyntaxKind`s in `kinds` exactly.
687 fn parents_match(mut node: NodeOrToken<SyntaxNode, SyntaxToken>, mut kinds: &[SyntaxKind]) -> bool {
688 while let (Some(parent), [kind, rest @ ..]) = (&node.parent(), kinds) {
689 if parent.kind() != *kind {
693 // FIXME: Would be nice to get parent out of the match, but binding by-move and by-value
694 // in the same pattern is unstable: rust-lang/rust#68354.
695 node = node.parent().unwrap().into();
699 // Only true if we matched all expected kinds
703 fn parent_matches<N: AstNode>(token: &SyntaxToken) -> bool {
704 token.parent().map_or(false, |it| N::can_cast(it.kind()))