15 use hir::{Name, Semantics};
16 use ide_db::RootDatabase;
17 use rustc_hash::FxHashMap;
19 ast::{self, HasFormatSpecifier},
20 AstNode, AstToken, Direction, NodeOrToken,
22 SyntaxNode, TextRange, WalkEvent, T,
26 syntax_highlighting::{
27 format::FormatStringHighlighter, highlights::Highlights,
28 macro_rules::MacroRulesHighlighter, tags::Highlight,
30 FileId, HlMod, HlTag, SymbolKind,
33 pub(crate) use html::highlight_as_html;
35 #[derive(Debug, Clone, Copy)]
38 pub highlight: Highlight,
39 pub binding_hash: Option<u64>,
42 // Feature: Semantic Syntax Highlighting
44 // rust-analyzer highlights the code semantically.
45 // For example, `bar` in `foo::Bar` might be colored differently depending on whether `Bar` is an enum or a trait.
46 // rust-analyzer does not specify colors directly, instead it assigns tag (like `struct`) and a set of modifiers (like `declaration`) to each token.
47 // It's up to the client to map those to specific colors.
49 // The general rule is that a reference to an entity gets colored the same way as the entity itself.
50 // We also give special modifier for `mut` and `&mut` local variables.
51 pub(crate) fn highlight(
54 range_to_highlight: Option<TextRange>,
55 syntactic_name_ref_highlighting: bool,
57 let _p = profile::span("highlight");
58 let sema = Semantics::new(db);
60 // Determine the root based on the given range.
61 let (root, range_to_highlight) = {
62 let source_file = sema.parse(file_id);
63 match range_to_highlight {
65 let node = match source_file.syntax().covering_element(range) {
66 NodeOrToken::Node(it) => it,
67 NodeOrToken::Token(it) => it.parent(),
71 None => (source_file.syntax().clone(), source_file.syntax().text_range()),
75 let mut hl = highlights::Highlights::new(range_to_highlight);
76 traverse(&mut hl, &sema, &root, range_to_highlight, syntactic_name_ref_highlighting);
82 sema: &Semantics<RootDatabase>,
84 range_to_highlight: TextRange,
85 syntactic_name_ref_highlighting: bool,
87 let mut bindings_shadow_count: FxHashMap<Name, u32> = FxHashMap::default();
89 let mut current_macro_call: Option<ast::MacroCall> = None;
90 let mut current_macro_rules: Option<ast::MacroRules> = None;
91 let mut format_string_highlighter = FormatStringHighlighter::default();
92 let mut macro_rules_highlighter = MacroRulesHighlighter::default();
93 let mut inside_attribute = false;
95 // Walk all nodes, keeping track of whether we are inside a macro or not.
96 // If in macro, expand it first and highlight the expanded code.
97 for event in root.preorder_with_tokens() {
98 let event_range = match &event {
99 WalkEvent::Enter(it) | WalkEvent::Leave(it) => it.text_range(),
102 // Element outside of the viewport, no need to highlight
103 if range_to_highlight.intersect(event_range).is_none() {
107 // Track "inside macro" state
108 match event.clone().map(|it| it.into_node().and_then(ast::MacroCall::cast)) {
109 WalkEvent::Enter(Some(mc)) => {
110 if let Some(range) = macro_call_range(&mc) {
113 highlight: HlTag::Symbol(SymbolKind::Macro).into(),
117 current_macro_call = Some(mc.clone());
120 WalkEvent::Leave(Some(mc)) => {
121 assert_eq!(current_macro_call, Some(mc));
122 current_macro_call = None;
123 format_string_highlighter = FormatStringHighlighter::default();
128 match event.clone().map(|it| it.into_node().and_then(ast::MacroRules::cast)) {
129 WalkEvent::Enter(Some(mac)) => {
130 macro_rules_highlighter.init();
131 current_macro_rules = Some(mac);
134 WalkEvent::Leave(Some(mac)) => {
135 assert_eq!(current_macro_rules, Some(mac));
136 current_macro_rules = None;
137 macro_rules_highlighter = MacroRulesHighlighter::default();
142 WalkEvent::Enter(NodeOrToken::Node(node)) if ast::Attr::can_cast(node.kind()) => {
143 inside_attribute = true
145 WalkEvent::Leave(NodeOrToken::Node(node)) if ast::Attr::can_cast(node.kind()) => {
146 inside_attribute = false
151 let element = match event {
152 WalkEvent::Enter(it) => it,
153 WalkEvent::Leave(it) => {
154 if let Some(node) = it.as_node() {
155 inject::doc_comment(hl, node);
161 let range = element.text_range();
163 if current_macro_rules.is_some() {
164 if let Some(tok) = element.as_token() {
165 macro_rules_highlighter.advance(tok);
169 let element_to_highlight = if current_macro_call.is_some() && element.kind() != COMMENT {
170 // Inside a macro -- expand it first
171 let token = match element.clone().into_token() {
172 Some(it) if it.parent().kind() == TOKEN_TREE => it,
175 let token = sema.descend_into_macros(token.clone());
176 let parent = token.parent();
178 format_string_highlighter.check_for_format_string(&parent);
180 // We only care Name and Name_ref
181 match (token.kind(), parent.kind()) {
182 (IDENT, NAME) | (IDENT, NAME_REF) => parent.into(),
189 if let Some(token) = element.as_token().cloned().and_then(ast::String::cast) {
191 let expanded = element_to_highlight.as_token().unwrap().clone();
192 if inject::ra_fixture(hl, &sema, token, expanded).is_some() {
198 if let Some((mut highlight, binding_hash)) = highlight::element(
200 &mut bindings_shadow_count,
201 syntactic_name_ref_highlighting,
202 element_to_highlight.clone(),
204 if inside_attribute {
205 highlight = highlight | HlMod::Attribute;
208 if macro_rules_highlighter.highlight(element_to_highlight.clone()).is_none() {
209 hl.add(HlRange { range, highlight, binding_hash });
212 if let Some(string) =
213 element_to_highlight.as_token().cloned().and_then(ast::String::cast)
215 format_string_highlighter.highlight_format_string(hl, &string, range);
216 // Highlight escape sequences
217 if let Some(char_ranges) = string.char_ranges() {
218 for (piece_range, _) in char_ranges.iter().filter(|(_, char)| char.is_ok()) {
219 if string.text()[piece_range.start().into()..].starts_with('\\') {
221 range: piece_range + range.start(),
222 highlight: HlTag::EscapeSequence.into(),
233 fn macro_call_range(macro_call: &ast::MacroCall) -> Option<TextRange> {
234 let path = macro_call.path()?;
235 let name_ref = path.segment()?.name_ref()?;
237 let range_start = name_ref.syntax().text_range().start();
238 let mut range_end = name_ref.syntax().text_range().end();
239 for sibling in path.syntax().siblings_with_tokens(Direction::Next) {
240 match sibling.kind() {
241 T![!] | IDENT => range_end = sibling.text_range().end(),
246 Some(TextRange::new(range_start, range_end))