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 a 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.
55 // Rust-analyzer currently emits the following token tags:
60 // enum:: Emitted for enums.
61 // function:: Emitted for free-standing functions.
62 // macro:: Emitted for macros.
63 // method:: Emitted for associated functions, also knowns as methods.
64 // namespace:: Emitted for modules.
65 // struct:: Emitted for structs.
66 // trait:: Emitted for traits.
67 // typeAlias:: Emitted for type aliases and `Self` in `impl`s.
68 // union:: Emitted for unions.
73 // boolean:: Emitted for the boolean literals `true` and `false`.
74 // character:: Emitted for character literals.
75 // number:: Emitted for numeric literals.
76 // string:: Emitted for string literals.
77 // escapeSequence:: Emitted for escaped sequences inside strings like `\n`.
78 // formatSpecifier:: Emitted for format specifiers `{:?}` in `format!`-like macros.
83 // operator:: Emitted for general operators.
84 // arithmetic:: Emitted for the arithmetic operators `+`, `-`, `*`, `/`, `+=`, `-=`, `*=`, `/=`.
85 // bitwise:: Emitted for the bitwise operators `|`, `&`, `!`, `^`, `|=`, `&=`, `^=`.
86 // comparison:: Emitted for the comparison operators `>`, `<`, `==`, `>=`, `<=`, `!=`.
87 // logical:: Emitted for the logical operators `||`, `&&`, `!`.
92 // punctuation:: Emitted for general punctuation.
93 // angle:: Emitted for `<>` angle brackets.
94 // brace:: Emitted for `{}` braces.
95 // bracket:: Emitted for `[]` brackets.
96 // parenthesis:: Emitted for `()` parentheses.
97 // colon:: Emitted for the `:` token.
98 // comma:: Emitted for the `,` token.
99 // dot:: Emitted for the `.` token.
100 // Semi:: Emitted for the `;` token.
105 // attribute:: Emitted for attributes.
106 // builtinType:: Emitted for builtin types like `u32`, `str` and `f32`.
107 // comment:: Emitted for comments.
108 // constParameter:: Emitted for const parameters.
109 // enumMember:: Emitted for enum variants.
110 // generic:: Emitted for generic tokens that have no mapping.
111 // keyword:: Emitted for keywords.
112 // label:: Emitted for labels.
113 // lifetime:: Emitted for lifetimes.
114 // parameter:: Emitted for non-self function parameters.
115 // property:: Emitted for struct and union fields.
116 // selfKeyword:: Emitted for the self function parameter and self path-specifier.
117 // typeParameter:: Emitted for type parameters.
118 // unresolvedReference:: Emitted for unresolved references, names that rust-analyzer can't find the definition of.
119 // variable:: Emitted for locals, constants and statics.
124 // Token modifiers allow to style some elements in the source code more precisely.
126 // Rust-analyzer currently emits the following token modifiers:
129 // async:: Emitted for async functions and the `async` and `await` keywords.
130 // attribute:: Emitted for tokens inside attributes.
131 // callable:: Emitted for locals whose types implements one of the `Fn*` traits.
132 // constant:: Emitted for consts.
133 // consuming:: Emitted for locals that are being consumed when use in a function call.
134 // controlFlow:: Emitted for control-flow related tokens, this includes the `?` operator.
135 // declaration:: Emitted for names of definitions, like `foo` in `fn foo() {}`.
136 // documentation:: Emitted for documentation comments.
137 // injected:: Emitted for doc-string injected highlighting like rust source blocks in documentation.
138 // intraDocLink:: Emitted for intra doc links in doc-strings.
139 // library:: Emitted for items that are defined outside of the current crate.
140 // mutable:: Emitted for mutable locals and statics.
141 // static:: Emitted for "static" functions, also known as functions that do not take a `self` param, as well as statics and consts.
142 // trait:: Emitted for associated trait items.
143 // unsafe:: Emitted for unsafe operations, like unsafe function calls, as well as the `unsafe` token.
146 // image::https://user-images.githubusercontent.com/48062697/113164457-06cfb980-9239-11eb-819b-0f93e646acf8.png[]
147 // image::https://user-images.githubusercontent.com/48062697/113187625-f7f50100-9250-11eb-825e-91c58f236071.png[]
148 pub(crate) fn highlight(
151 range_to_highlight: Option<TextRange>,
152 syntactic_name_ref_highlighting: bool,
154 let _p = profile::span("highlight");
155 let sema = Semantics::new(db);
157 // Determine the root based on the given range.
158 let (root, range_to_highlight) = {
159 let source_file = sema.parse(file_id);
160 match range_to_highlight {
162 let node = match source_file.syntax().covering_element(range) {
163 NodeOrToken::Node(it) => it,
164 NodeOrToken::Token(it) => it.parent().unwrap(),
168 None => (source_file.syntax().clone(), source_file.syntax().text_range()),
172 let mut hl = highlights::Highlights::new(root.text_range());
176 InFile::new(file_id.into(), &root),
177 sema.scope(&root).krate(),
179 syntactic_name_ref_highlighting,
186 sema: &Semantics<RootDatabase>,
187 root: InFile<&SyntaxNode>,
188 krate: Option<hir::Crate>,
189 range_to_highlight: TextRange,
190 syntactic_name_ref_highlighting: bool,
192 let mut bindings_shadow_count: FxHashMap<Name, u32> = FxHashMap::default();
194 let mut current_macro_call: Option<ast::MacroCall> = None;
195 let mut current_attr_macro_call = None;
196 let mut current_macro: Option<ast::Macro> = None;
197 let mut macro_highlighter = MacroHighlighter::default();
198 let mut inside_attribute = false;
200 // Walk all nodes, keeping track of whether we are inside a macro or not.
201 // If in macro, expand it first and highlight the expanded code.
202 for event in root.value.preorder_with_tokens() {
203 let event_range = match &event {
204 WalkEvent::Enter(it) | WalkEvent::Leave(it) => it.text_range(),
207 // Element outside of the viewport, no need to highlight
208 if range_to_highlight.intersect(event_range).is_none() {
212 // Track "inside macro" state
213 match event.clone().map(|it| it.into_node().and_then(ast::MacroCall::cast)) {
214 WalkEvent::Enter(Some(mc)) => {
215 if let Some(range) = macro_call_range(&mc) {
218 highlight: HlTag::Symbol(SymbolKind::Macro).into(),
222 current_macro_call = Some(mc.clone());
225 WalkEvent::Leave(Some(mc)) => {
226 assert_eq!(current_macro_call, Some(mc));
227 current_macro_call = None;
231 match event.clone().map(|it| it.into_node().and_then(ast::Item::cast)) {
232 WalkEvent::Enter(Some(item)) => {
233 if sema.is_attr_macro_call(&item) {
234 current_attr_macro_call = Some(item);
237 WalkEvent::Leave(Some(item)) => {
238 if current_attr_macro_call == Some(item) {
239 current_attr_macro_call = None;
245 match event.clone().map(|it| it.into_node().and_then(ast::Macro::cast)) {
246 WalkEvent::Enter(Some(mac)) => {
247 macro_highlighter.init();
248 current_macro = Some(mac);
251 WalkEvent::Leave(Some(mac)) => {
252 assert_eq!(current_macro, Some(mac));
253 current_macro = None;
254 macro_highlighter = MacroHighlighter::default();
259 WalkEvent::Enter(NodeOrToken::Node(node)) if ast::Attr::can_cast(node.kind()) => {
260 inside_attribute = true
262 WalkEvent::Leave(NodeOrToken::Node(node)) if ast::Attr::can_cast(node.kind()) => {
263 inside_attribute = false
268 let element = match event {
269 WalkEvent::Enter(it) => it,
270 WalkEvent::Leave(it) => {
271 if let Some(node) = it.as_node() {
272 inject::doc_comment(hl, sema, root.with_value(node));
278 let range = element.text_range();
280 if current_macro.is_some() {
281 if let Some(tok) = element.as_token() {
282 macro_highlighter.advance(tok);
286 let element_to_highlight = if current_macro_call.is_some() && element.kind() != COMMENT {
287 // Inside a macro -- expand it first
288 let token = match element.clone().into_token() {
289 Some(it) if it.parent().map_or(false, |it| it.kind() == TOKEN_TREE) => it,
292 let token = sema.descend_into_macros(token.clone());
293 match token.parent() {
295 // We only care Name and Name_ref
296 match (token.kind(), parent.kind()) {
297 (IDENT, NAME) | (IDENT, NAME_REF) => parent.into(),
301 None => token.into(),
303 } else if current_attr_macro_call.is_some() {
304 let token = match element.clone().into_token() {
308 let token = sema.descend_into_macros(token.clone());
309 match token.parent() {
311 // We only care Name and Name_ref
312 match (token.kind(), parent.kind()) {
313 (IDENT, NAME) | (IDENT, NAME_REF) => parent.into(),
317 None => token.into(),
323 if let Some(token) = element.as_token().cloned().and_then(ast::String::cast) {
325 let expanded = element_to_highlight.as_token().unwrap().clone();
326 if inject::ra_fixture(hl, &sema, token, expanded).is_some() {
332 if let Some(_) = macro_highlighter.highlight(element_to_highlight.clone()) {
336 if let Some((mut highlight, binding_hash)) = highlight::element(
339 &mut bindings_shadow_count,
340 syntactic_name_ref_highlighting,
341 element_to_highlight.clone(),
343 if inside_attribute {
344 highlight = highlight | HlMod::Attribute;
347 hl.add(HlRange { range, highlight, binding_hash });
350 if let Some(string) = element_to_highlight.as_token().cloned().and_then(ast::String::cast) {
351 highlight_format_string(hl, &string, range);
352 // Highlight escape sequences
353 if let Some(char_ranges) = string.char_ranges() {
354 for (piece_range, _) in char_ranges.iter().filter(|(_, char)| char.is_ok()) {
355 if string.text()[piece_range.start().into()..].starts_with('\\') {
357 range: piece_range + range.start(),
358 highlight: HlTag::EscapeSequence.into(),
368 fn macro_call_range(macro_call: &ast::MacroCall) -> Option<TextRange> {
369 let path = macro_call.path()?;
370 let name_ref = path.segment()?.name_ref()?;
372 let range_start = name_ref.syntax().text_range().start();
373 let mut range_end = name_ref.syntax().text_range().end();
374 for sibling in path.syntax().siblings_with_tokens(Direction::Next) {
375 match sibling.kind() {
376 T![!] | IDENT => range_end = sibling.text_range().end(),
381 Some(TextRange::new(range_start, range_end))