pub(crate) mod tags; mod highlights; mod injector; mod format; mod injection; mod macro_rules; mod html; #[cfg(test)] mod tests; use hir::{AsAssocItem, Local, Name, Semantics, VariantDef}; use ide_db::{ defs::{Definition, NameClass, NameRefClass}, RootDatabase, }; use rustc_hash::FxHashMap; use syntax::{ ast::{self, HasFormatSpecifier}, AstNode, AstToken, Direction, NodeOrToken, SyntaxElement, SyntaxKind::{self, *}, SyntaxNode, SyntaxToken, TextRange, WalkEvent, T, }; use crate::{ syntax_highlighting::{ format::FormatStringHighlighter, macro_rules::MacroRulesHighlighter, tags::Highlight, }, FileId, HlMod, HlTag, SymbolKind, }; pub(crate) use html::highlight_as_html; #[derive(Debug, Clone, Copy)] pub struct HlRange { pub range: TextRange, pub highlight: Highlight, pub binding_hash: Option, } // Feature: Semantic Syntax Highlighting // // rust-analyzer highlights the code semantically. // For example, `bar` in `foo::Bar` might be colored differently depending on whether `Bar` is an enum or a trait. // rust-analyzer does not specify colors directly, instead it assigns tag (like `struct`) and a set of modifiers (like `declaration`) to each token. // It's up to the client to map those to specific colors. // // The general rule is that a reference to an entity gets colored the same way as the entity itself. // We also give special modifier for `mut` and `&mut` local variables. pub(crate) fn highlight( db: &RootDatabase, file_id: FileId, range_to_highlight: Option, syntactic_name_ref_highlighting: bool, ) -> Vec { let _p = profile::span("highlight"); let sema = Semantics::new(db); // Determine the root based on the given range. let (root, range_to_highlight) = { let source_file = sema.parse(file_id); match range_to_highlight { Some(range) => { let node = match source_file.syntax().covering_element(range) { NodeOrToken::Node(it) => it, NodeOrToken::Token(it) => it.parent(), }; (node, range) } None => (source_file.syntax().clone(), source_file.syntax().text_range()), } }; let mut bindings_shadow_count: FxHashMap = FxHashMap::default(); let mut hl = highlights::Highlights::new(range_to_highlight); let mut current_macro_call: Option = None; let mut current_macro_rules: Option = None; let mut format_string_highlighter = FormatStringHighlighter::default(); let mut macro_rules_highlighter = MacroRulesHighlighter::default(); let mut inside_attribute = false; // Walk all nodes, keeping track of whether we are inside a macro or not. // If in macro, expand it first and highlight the expanded code. for event in root.preorder_with_tokens() { let event_range = match &event { WalkEvent::Enter(it) | WalkEvent::Leave(it) => it.text_range(), }; // Element outside of the viewport, no need to highlight if range_to_highlight.intersect(event_range).is_none() { continue; } // Track "inside macro" state match event.clone().map(|it| it.into_node().and_then(ast::MacroCall::cast)) { WalkEvent::Enter(Some(mc)) => { if let Some(range) = macro_call_range(&mc) { hl.add(HlRange { range, highlight: HlTag::Symbol(SymbolKind::Macro).into(), binding_hash: None, }); } current_macro_call = Some(mc.clone()); continue; } WalkEvent::Leave(Some(mc)) => { assert_eq!(current_macro_call, Some(mc)); current_macro_call = None; format_string_highlighter = FormatStringHighlighter::default(); } _ => (), } match event.clone().map(|it| it.into_node().and_then(ast::MacroRules::cast)) { WalkEvent::Enter(Some(mac)) => { macro_rules_highlighter.init(); current_macro_rules = Some(mac); continue; } WalkEvent::Leave(Some(mac)) => { assert_eq!(current_macro_rules, Some(mac)); current_macro_rules = None; macro_rules_highlighter = MacroRulesHighlighter::default(); } _ => (), } match &event { // Check for Rust code in documentation WalkEvent::Leave(NodeOrToken::Node(node)) => { if ast::Attr::can_cast(node.kind()) { inside_attribute = false } if let Some((new_comments, inj)) = injection::extract_doc_comments(node) { injection::highlight_doc_comment(new_comments, inj, &mut hl); } } WalkEvent::Enter(NodeOrToken::Node(node)) if ast::Attr::can_cast(node.kind()) => { inside_attribute = true } _ => (), } let element = match event { WalkEvent::Enter(it) => it, WalkEvent::Leave(_) => continue, }; let range = element.text_range(); if current_macro_rules.is_some() { if let Some(tok) = element.as_token() { macro_rules_highlighter.advance(tok); } } let element_to_highlight = if current_macro_call.is_some() && element.kind() != COMMENT { // Inside a macro -- expand it first let token = match element.clone().into_token() { Some(it) if it.parent().kind() == TOKEN_TREE => it, _ => continue, }; let token = sema.descend_into_macros(token.clone()); let parent = token.parent(); format_string_highlighter.check_for_format_string(&parent); // We only care Name and Name_ref match (token.kind(), parent.kind()) { (IDENT, NAME) | (IDENT, NAME_REF) => parent.into(), _ => token.into(), } } else { element.clone() }; if let Some(token) = element.as_token().cloned().and_then(ast::String::cast) { if token.is_raw() { let expanded = element_to_highlight.as_token().unwrap().clone(); if injection::highlight_injection(&mut hl, &sema, token, expanded).is_some() { continue; } } } if let Some((mut highlight, binding_hash)) = highlight_element( &sema, &mut bindings_shadow_count, syntactic_name_ref_highlighting, element_to_highlight.clone(), ) { if inside_attribute { highlight = highlight | HlMod::Attribute; } if macro_rules_highlighter.highlight(element_to_highlight.clone()).is_none() { hl.add(HlRange { range, highlight, binding_hash }); } if let Some(string) = element_to_highlight.as_token().cloned().and_then(ast::String::cast) { format_string_highlighter.highlight_format_string(&mut hl, &string, range); // Highlight escape sequences if let Some(char_ranges) = string.char_ranges() { for (piece_range, _) in char_ranges.iter().filter(|(_, char)| char.is_ok()) { if string.text()[piece_range.start().into()..].starts_with('\\') { hl.add(HlRange { range: piece_range + range.start(), highlight: HlTag::EscapeSequence.into(), binding_hash: None, }); } } } } } } hl.to_vec() } fn macro_call_range(macro_call: &ast::MacroCall) -> Option { let path = macro_call.path()?; let name_ref = path.segment()?.name_ref()?; let range_start = name_ref.syntax().text_range().start(); let mut range_end = name_ref.syntax().text_range().end(); for sibling in path.syntax().siblings_with_tokens(Direction::Next) { match sibling.kind() { T![!] | IDENT => range_end = sibling.text_range().end(), _ => (), } } Some(TextRange::new(range_start, range_end)) } /// Returns true if the parent nodes of `node` all match the `SyntaxKind`s in `kinds` exactly. fn parents_match(mut node: NodeOrToken, mut kinds: &[SyntaxKind]) -> bool { while let (Some(parent), [kind, rest @ ..]) = (&node.parent(), kinds) { if parent.kind() != *kind { return false; } // FIXME: Would be nice to get parent out of the match, but binding by-move and by-value // in the same pattern is unstable: rust-lang/rust#68354. node = node.parent().unwrap().into(); kinds = rest; } // Only true if we matched all expected kinds kinds.len() == 0 } fn is_consumed_lvalue( node: NodeOrToken, local: &Local, db: &RootDatabase, ) -> bool { // When lvalues are passed as arguments and they're not Copy, then mark them as Consuming. parents_match(node, &[PATH_SEGMENT, PATH, PATH_EXPR, ARG_LIST]) && !local.ty(db).is_copy(db) } fn highlight_element( sema: &Semantics, bindings_shadow_count: &mut FxHashMap, syntactic_name_ref_highlighting: bool, element: SyntaxElement, ) -> Option<(Highlight, Option)> { let db = sema.db; let mut binding_hash = None; let highlight: Highlight = match element.kind() { FN => { bindings_shadow_count.clear(); return None; } // Highlight definitions depending on the "type" of the definition. NAME => { let name = element.into_node().and_then(ast::Name::cast).unwrap(); let name_kind = NameClass::classify(sema, &name); if let Some(NameClass::Definition(Definition::Local(local))) = &name_kind { if let Some(name) = local.name(db) { let shadow_count = bindings_shadow_count.entry(name.clone()).or_default(); *shadow_count += 1; binding_hash = Some(calc_binding_hash(&name, *shadow_count)) } }; match name_kind { Some(NameClass::ExternCrate(_)) => HlTag::Symbol(SymbolKind::Module).into(), Some(NameClass::Definition(def)) => highlight_def(db, def) | HlMod::Definition, Some(NameClass::ConstReference(def)) => highlight_def(db, def), Some(NameClass::PatFieldShorthand { field_ref, .. }) => { let mut h = HlTag::Symbol(SymbolKind::Field).into(); if let Definition::Field(field) = field_ref { if let VariantDef::Union(_) = field.parent_def(db) { h |= HlMod::Unsafe; } } h } None => highlight_name_by_syntax(name) | HlMod::Definition, } } // Highlight references like the definitions they resolve to NAME_REF if element.ancestors().any(|it| it.kind() == ATTR) => { // even though we track whether we are in an attribute or not we still need this special case // as otherwise we would emit unresolved references for name refs inside attributes Highlight::from(HlTag::Symbol(SymbolKind::Function)) } NAME_REF => { let name_ref = element.into_node().and_then(ast::NameRef::cast).unwrap(); highlight_func_by_name_ref(sema, &name_ref).unwrap_or_else(|| { match NameRefClass::classify(sema, &name_ref) { Some(name_kind) => match name_kind { NameRefClass::ExternCrate(_) => HlTag::Symbol(SymbolKind::Module).into(), NameRefClass::Definition(def) => { if let Definition::Local(local) = &def { if let Some(name) = local.name(db) { let shadow_count = bindings_shadow_count.entry(name.clone()).or_default(); binding_hash = Some(calc_binding_hash(&name, *shadow_count)) } }; let mut h = highlight_def(db, def); if let Definition::Local(local) = &def { if is_consumed_lvalue(name_ref.syntax().clone().into(), local, db) { h |= HlMod::Consuming; } } if let Some(parent) = name_ref.syntax().parent() { if matches!(parent.kind(), FIELD_EXPR | RECORD_PAT_FIELD) { if let Definition::Field(field) = def { if let VariantDef::Union(_) = field.parent_def(db) { h |= HlMod::Unsafe; } } } } h } NameRefClass::FieldShorthand { .. } => { HlTag::Symbol(SymbolKind::Field).into() } }, None if syntactic_name_ref_highlighting => { highlight_name_ref_by_syntax(name_ref, sema) } None => HlTag::UnresolvedReference.into(), } }) } // Simple token-based highlighting COMMENT => { let comment = element.into_token().and_then(ast::Comment::cast)?; let h = HlTag::Comment; match comment.kind().doc { Some(_) => h | HlMod::Documentation, None => h.into(), } } STRING | BYTE_STRING => HlTag::StringLiteral.into(), ATTR => HlTag::Attribute.into(), INT_NUMBER | FLOAT_NUMBER => HlTag::NumericLiteral.into(), BYTE => HlTag::ByteLiteral.into(), CHAR => HlTag::CharLiteral.into(), QUESTION => Highlight::new(HlTag::Operator) | HlMod::ControlFlow, LIFETIME => { let lifetime = element.into_node().and_then(ast::Lifetime::cast).unwrap(); match NameClass::classify_lifetime(sema, &lifetime) { Some(NameClass::Definition(def)) => highlight_def(db, def) | HlMod::Definition, None => match NameRefClass::classify_lifetime(sema, &lifetime) { Some(NameRefClass::Definition(def)) => highlight_def(db, def), _ => Highlight::new(HlTag::Symbol(SymbolKind::LifetimeParam)), }, _ => Highlight::new(HlTag::Symbol(SymbolKind::LifetimeParam)) | HlMod::Definition, } } p if p.is_punct() => match p { T![&] => { let h = HlTag::Operator.into(); let is_unsafe = element .parent() .and_then(ast::RefExpr::cast) .map(|ref_expr| sema.is_unsafe_ref_expr(&ref_expr)) .unwrap_or(false); if is_unsafe { h | HlMod::Unsafe } else { h } } T![::] | T![->] | T![=>] | T![..] | T![=] | T![@] | T![.] => HlTag::Operator.into(), T![!] if element.parent().and_then(ast::MacroCall::cast).is_some() => { HlTag::Symbol(SymbolKind::Macro).into() } T![!] if element.parent().and_then(ast::NeverType::cast).is_some() => { HlTag::BuiltinType.into() } T![*] if element.parent().and_then(ast::PtrType::cast).is_some() => { HlTag::Keyword.into() } T![*] if element.parent().and_then(ast::PrefixExpr::cast).is_some() => { let prefix_expr = element.parent().and_then(ast::PrefixExpr::cast)?; let expr = prefix_expr.expr()?; let ty = sema.type_of_expr(&expr)?; if ty.is_raw_ptr() { HlTag::Operator | HlMod::Unsafe } else if let Some(ast::PrefixOp::Deref) = prefix_expr.op_kind() { HlTag::Operator.into() } else { HlTag::Punctuation.into() } } T![-] if element.parent().and_then(ast::PrefixExpr::cast).is_some() => { let prefix_expr = element.parent().and_then(ast::PrefixExpr::cast)?; let expr = prefix_expr.expr()?; match expr { ast::Expr::Literal(_) => HlTag::NumericLiteral, _ => HlTag::Operator, } .into() } _ if element.parent().and_then(ast::PrefixExpr::cast).is_some() => { HlTag::Operator.into() } _ if element.parent().and_then(ast::BinExpr::cast).is_some() => HlTag::Operator.into(), _ if element.parent().and_then(ast::RangeExpr::cast).is_some() => { HlTag::Operator.into() } _ if element.parent().and_then(ast::RangePat::cast).is_some() => HlTag::Operator.into(), _ if element.parent().and_then(ast::RestPat::cast).is_some() => HlTag::Operator.into(), _ if element.parent().and_then(ast::Attr::cast).is_some() => HlTag::Attribute.into(), _ => HlTag::Punctuation.into(), }, k if k.is_keyword() => { let h = Highlight::new(HlTag::Keyword); match k { T![break] | T![continue] | T![else] | T![if] | T![loop] | T![match] | T![return] | T![while] | T![in] => h | HlMod::ControlFlow, T![for] if !is_child_of_impl(&element) => h | HlMod::ControlFlow, T![unsafe] => h | HlMod::Unsafe, T![true] | T![false] => HlTag::BoolLiteral.into(), T![self] => { let self_param_is_mut = element .parent() .and_then(ast::SelfParam::cast) .and_then(|p| p.mut_token()) .is_some(); let self_path = &element .parent() .as_ref() .and_then(SyntaxNode::parent) .and_then(ast::Path::cast) .and_then(|p| sema.resolve_path(&p)); let mut h = HlTag::Symbol(SymbolKind::SelfParam).into(); if self_param_is_mut || matches!(self_path, Some(hir::PathResolution::Local(local)) if local.is_self(db) && (local.is_mut(db) || local.ty(db).is_mutable_reference()) ) { h |= HlMod::Mutable } if let Some(hir::PathResolution::Local(local)) = self_path { if is_consumed_lvalue(element, &local, db) { h |= HlMod::Consuming; } } h } T![ref] => element .parent() .and_then(ast::IdentPat::cast) .and_then(|ident_pat| { if sema.is_unsafe_ident_pat(&ident_pat) { Some(HlMod::Unsafe) } else { None } }) .map(|modifier| h | modifier) .unwrap_or(h), _ => h, } } _ => return None, }; return Some((highlight, binding_hash)); fn calc_binding_hash(name: &Name, shadow_count: u32) -> u64 { fn hash(x: T) -> u64 { use std::{collections::hash_map::DefaultHasher, hash::Hasher}; let mut hasher = DefaultHasher::new(); x.hash(&mut hasher); hasher.finish() } hash((name, shadow_count)) } } fn is_child_of_impl(element: &SyntaxElement) -> bool { match element.parent() { Some(e) => e.kind() == IMPL, _ => false, } } fn highlight_func_by_name_ref( sema: &Semantics, name_ref: &ast::NameRef, ) -> Option { let method_call = name_ref.syntax().parent().and_then(ast::MethodCallExpr::cast)?; highlight_method_call(sema, &method_call) } fn highlight_method_call( sema: &Semantics, method_call: &ast::MethodCallExpr, ) -> Option { let func = sema.resolve_method_call(&method_call)?; let mut h = HlTag::Symbol(SymbolKind::Function).into(); h |= HlMod::Associated; if func.is_unsafe(sema.db) || sema.is_unsafe_method_call(&method_call) { h |= HlMod::Unsafe; } if let Some(self_param) = func.self_param(sema.db) { match self_param.access(sema.db) { hir::Access::Shared => (), hir::Access::Exclusive => h |= HlMod::Mutable, hir::Access::Owned => { if let Some(receiver_ty) = method_call.receiver().and_then(|it| sema.type_of_expr(&it)) { if !receiver_ty.is_copy(sema.db) { h |= HlMod::Consuming } } } } } Some(h) } fn highlight_def(db: &RootDatabase, def: Definition) -> Highlight { match def { Definition::Macro(_) => HlTag::Symbol(SymbolKind::Macro), Definition::Field(_) => HlTag::Symbol(SymbolKind::Field), Definition::ModuleDef(def) => match def { hir::ModuleDef::Module(_) => HlTag::Symbol(SymbolKind::Module), hir::ModuleDef::Function(func) => { let mut h = Highlight::new(HlTag::Symbol(SymbolKind::Function)); if func.as_assoc_item(db).is_some() { h |= HlMod::Associated; if func.self_param(db).is_none() { h |= HlMod::Static } } if func.is_unsafe(db) { h |= HlMod::Unsafe; } return h; } hir::ModuleDef::Adt(hir::Adt::Struct(_)) => HlTag::Symbol(SymbolKind::Struct), hir::ModuleDef::Adt(hir::Adt::Enum(_)) => HlTag::Symbol(SymbolKind::Enum), hir::ModuleDef::Adt(hir::Adt::Union(_)) => HlTag::Symbol(SymbolKind::Union), hir::ModuleDef::Variant(_) => HlTag::Symbol(SymbolKind::Variant), hir::ModuleDef::Const(konst) => { let mut h = Highlight::new(HlTag::Symbol(SymbolKind::Const)); if konst.as_assoc_item(db).is_some() { h |= HlMod::Associated } return h; } hir::ModuleDef::Trait(_) => HlTag::Symbol(SymbolKind::Trait), hir::ModuleDef::TypeAlias(type_) => { let mut h = Highlight::new(HlTag::Symbol(SymbolKind::TypeAlias)); if type_.as_assoc_item(db).is_some() { h |= HlMod::Associated } return h; } hir::ModuleDef::BuiltinType(_) => HlTag::BuiltinType, hir::ModuleDef::Static(s) => { let mut h = Highlight::new(HlTag::Symbol(SymbolKind::Static)); if s.is_mut(db) { h |= HlMod::Mutable; h |= HlMod::Unsafe; } return h; } }, Definition::SelfType(_) => HlTag::Symbol(SymbolKind::Impl), Definition::TypeParam(_) => HlTag::Symbol(SymbolKind::TypeParam), Definition::ConstParam(_) => HlTag::Symbol(SymbolKind::ConstParam), Definition::Local(local) => { let tag = if local.is_param(db) { HlTag::Symbol(SymbolKind::ValueParam) } else { HlTag::Symbol(SymbolKind::Local) }; let mut h = Highlight::new(tag); if local.is_mut(db) || local.ty(db).is_mutable_reference() { h |= HlMod::Mutable; } if local.ty(db).as_callable(db).is_some() || local.ty(db).impls_fnonce(db) { h |= HlMod::Callable; } return h; } Definition::LifetimeParam(_) => HlTag::Symbol(SymbolKind::LifetimeParam), Definition::Label(_) => HlTag::Symbol(SymbolKind::Label), } .into() } fn highlight_name_by_syntax(name: ast::Name) -> Highlight { let default = HlTag::UnresolvedReference; let parent = match name.syntax().parent() { Some(it) => it, _ => return default.into(), }; let tag = match parent.kind() { STRUCT => HlTag::Symbol(SymbolKind::Struct), ENUM => HlTag::Symbol(SymbolKind::Enum), VARIANT => HlTag::Symbol(SymbolKind::Variant), UNION => HlTag::Symbol(SymbolKind::Union), TRAIT => HlTag::Symbol(SymbolKind::Trait), TYPE_ALIAS => HlTag::Symbol(SymbolKind::TypeAlias), TYPE_PARAM => HlTag::Symbol(SymbolKind::TypeParam), RECORD_FIELD => HlTag::Symbol(SymbolKind::Field), MODULE => HlTag::Symbol(SymbolKind::Module), FN => HlTag::Symbol(SymbolKind::Function), CONST => HlTag::Symbol(SymbolKind::Const), STATIC => HlTag::Symbol(SymbolKind::Static), IDENT_PAT => HlTag::Symbol(SymbolKind::Local), _ => default, }; tag.into() } fn highlight_name_ref_by_syntax(name: ast::NameRef, sema: &Semantics) -> Highlight { let default = HlTag::UnresolvedReference; let parent = match name.syntax().parent() { Some(it) => it, _ => return default.into(), }; match parent.kind() { METHOD_CALL_EXPR => { return ast::MethodCallExpr::cast(parent) .and_then(|method_call| highlight_method_call(sema, &method_call)) .unwrap_or_else(|| HlTag::Symbol(SymbolKind::Function).into()); } FIELD_EXPR => { let h = HlTag::Symbol(SymbolKind::Field); let is_union = ast::FieldExpr::cast(parent) .and_then(|field_expr| { let field = sema.resolve_field(&field_expr)?; Some(if let VariantDef::Union(_) = field.parent_def(sema.db) { true } else { false }) }) .unwrap_or(false); if is_union { h | HlMod::Unsafe } else { h.into() } } PATH_SEGMENT => { let path = match parent.parent().and_then(ast::Path::cast) { Some(it) => it, _ => return default.into(), }; let expr = match path.syntax().parent().and_then(ast::PathExpr::cast) { Some(it) => it, _ => { // within path, decide whether it is module or adt by checking for uppercase name return if name.text().chars().next().unwrap_or_default().is_uppercase() { HlTag::Symbol(SymbolKind::Struct) } else { HlTag::Symbol(SymbolKind::Module) } .into(); } }; let parent = match expr.syntax().parent() { Some(it) => it, None => return default.into(), }; match parent.kind() { CALL_EXPR => HlTag::Symbol(SymbolKind::Function).into(), _ => if name.text().chars().next().unwrap_or_default().is_uppercase() { HlTag::Symbol(SymbolKind::Struct) } else { HlTag::Symbol(SymbolKind::Const) } .into(), } } _ => default.into(), } }