15 use hir::{InFile, Name, Semantics};
16 use ide_db::{RootDatabase, SymbolKind};
17 use rustc_hash::FxHashMap;
19 ast::{self, HasFormatSpecifier},
20 AstNode, AstToken, Direction, NodeOrToken,
22 SyntaxNode, TextRange, WalkEvent, T,
26 syntax_highlighting::{
27 format::highlight_format_string, highlights::Highlights, macro_::MacroHighlighter,
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().unwrap(),
71 None => (source_file.syntax().clone(), source_file.syntax().text_range()),
75 let mut hl = highlights::Highlights::new(root.text_range());
79 InFile::new(file_id.into(), &root),
81 syntactic_name_ref_highlighting,
88 sema: &Semantics<RootDatabase>,
89 root: InFile<&SyntaxNode>,
90 range_to_highlight: TextRange,
91 syntactic_name_ref_highlighting: bool,
93 let mut bindings_shadow_count: FxHashMap<Name, u32> = FxHashMap::default();
95 let mut current_macro_call: Option<ast::MacroCall> = None;
96 let mut current_macro: Option<ast::Macro> = None;
97 let mut macro_highlighter = MacroHighlighter::default();
98 let mut inside_attribute = false;
100 // Walk all nodes, keeping track of whether we are inside a macro or not.
101 // If in macro, expand it first and highlight the expanded code.
102 for event in root.value.preorder_with_tokens() {
103 let event_range = match &event {
104 WalkEvent::Enter(it) | WalkEvent::Leave(it) => it.text_range(),
107 // Element outside of the viewport, no need to highlight
108 if range_to_highlight.intersect(event_range).is_none() {
112 // Track "inside macro" state
113 match event.clone().map(|it| it.into_node().and_then(ast::MacroCall::cast)) {
114 WalkEvent::Enter(Some(mc)) => {
115 if let Some(range) = macro_call_range(&mc) {
118 highlight: HlTag::Symbol(SymbolKind::Macro).into(),
122 current_macro_call = Some(mc.clone());
125 WalkEvent::Leave(Some(mc)) => {
126 assert_eq!(current_macro_call, Some(mc));
127 current_macro_call = None;
132 match event.clone().map(|it| it.into_node().and_then(ast::Macro::cast)) {
133 WalkEvent::Enter(Some(mac)) => {
134 macro_highlighter.init();
135 current_macro = Some(mac);
138 WalkEvent::Leave(Some(mac)) => {
139 assert_eq!(current_macro, Some(mac));
140 current_macro = None;
141 macro_highlighter = MacroHighlighter::default();
146 WalkEvent::Enter(NodeOrToken::Node(node)) if ast::Attr::can_cast(node.kind()) => {
147 inside_attribute = true
149 WalkEvent::Leave(NodeOrToken::Node(node)) if ast::Attr::can_cast(node.kind()) => {
150 inside_attribute = false
155 let element = match event {
156 WalkEvent::Enter(it) => it,
157 WalkEvent::Leave(it) => {
158 if let Some(node) = it.as_node() {
159 inject::doc_comment(hl, sema, root.with_value(node));
165 let range = element.text_range();
167 if current_macro.is_some() {
168 if let Some(tok) = element.as_token() {
169 macro_highlighter.advance(tok);
173 let element_to_highlight = if current_macro_call.is_some() && element.kind() != COMMENT {
174 // Inside a macro -- expand it first
175 let token = match element.clone().into_token() {
176 Some(it) if it.parent().map_or(false, |it| it.kind() == TOKEN_TREE) => it,
179 let token = sema.descend_into_macros(token.clone());
180 match token.parent() {
182 // We only care Name and Name_ref
183 match (token.kind(), parent.kind()) {
184 (IDENT, NAME) | (IDENT, NAME_REF) => parent.into(),
188 None => token.into(),
194 if let Some(token) = element.as_token().cloned().and_then(ast::String::cast) {
196 let expanded = element_to_highlight.as_token().unwrap().clone();
197 if inject::ra_fixture(hl, &sema, token, expanded).is_some() {
203 if let Some(_) = macro_highlighter.highlight(element_to_highlight.clone()) {
207 if let Some((mut highlight, binding_hash)) = highlight::element(
209 &mut bindings_shadow_count,
210 syntactic_name_ref_highlighting,
211 element_to_highlight.clone(),
213 if inside_attribute {
214 highlight = highlight | HlMod::Attribute;
217 hl.add(HlRange { range, highlight, binding_hash });
220 if let Some(string) = element_to_highlight.as_token().cloned().and_then(ast::String::cast) {
221 highlight_format_string(hl, &string, range);
222 // Highlight escape sequences
223 if let Some(char_ranges) = string.char_ranges() {
224 for (piece_range, _) in char_ranges.iter().filter(|(_, char)| char.is_ok()) {
225 if string.text()[piece_range.start().into()..].starts_with('\\') {
227 range: piece_range + range.start(),
228 highlight: HlTag::EscapeSequence.into(),
238 fn macro_call_range(macro_call: &ast::MacroCall) -> Option<TextRange> {
239 let path = macro_call.path()?;
240 let name_ref = path.segment()?.name_ref()?;
242 let range_start = name_ref.syntax().text_range().start();
243 let mut range_end = name_ref.syntax().text_range().end();
244 for sibling in path.syntax().siblings_with_tokens(Direction::Next) {
245 match sibling.kind() {
246 T![!] | IDENT => range_end = sibling.text_range().end(),
251 Some(TextRange::new(range_start, range_end))