15 use hir::{InFile, Name, Semantics};
16 use ide_db::{RootDatabase, SymbolKind};
17 use rustc_hash::FxHashMap;
19 ast::{self, HasFormatSpecifier},
20 match_ast, 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 the `#[` `]` tokens.
106 // builtinAttribute:: Emitted for names to builtin attributes in attribute path, the `repr` in `#[repr(u8)]` for example.
107 // builtinType:: Emitted for builtin types like `u32`, `str` and `f32`.
108 // comment:: Emitted for comments.
109 // constParameter:: Emitted for const parameters.
110 // enumMember:: Emitted for enum variants.
111 // generic:: Emitted for generic tokens that have no mapping.
112 // keyword:: Emitted for keywords.
113 // label:: Emitted for labels.
114 // lifetime:: Emitted for lifetimes.
115 // parameter:: Emitted for non-self function parameters.
116 // property:: Emitted for struct and union fields.
117 // selfKeyword:: Emitted for the self function parameter and self path-specifier.
118 // typeParameter:: Emitted for type parameters.
119 // unresolvedReference:: Emitted for unresolved references, names that rust-analyzer can't find the definition of.
120 // variable:: Emitted for locals, constants and statics.
125 // Token modifiers allow to style some elements in the source code more precisely.
127 // Rust-analyzer currently emits the following token modifiers:
130 // async:: Emitted for async functions and the `async` and `await` keywords.
131 // attribute:: Emitted for tokens inside attributes.
132 // callable:: Emitted for locals whose types implements one of the `Fn*` traits.
133 // constant:: Emitted for consts.
134 // consuming:: Emitted for locals that are being consumed when use in a function call.
135 // controlFlow:: Emitted for control-flow related tokens, this includes the `?` operator.
136 // crateRoot:: Emitted for crate names, like `serde` and `crate`.
137 // declaration:: Emitted for names of definitions, like `foo` in `fn foo() {}`.
138 // defaultLibrary:: Emitted for items from built-in crates (std, core, alloc, test and proc_macro).
139 // documentation:: Emitted for documentation comments.
140 // injected:: Emitted for doc-string injected highlighting like rust source blocks in documentation.
141 // intraDocLink:: Emitted for intra doc links in doc-strings.
142 // library:: Emitted for items that are defined outside of the current crate.
143 // mutable:: Emitted for mutable locals and statics as well as functions taking `&mut self`.
144 // public:: Emitted for items that are from the current crate and are `pub`.
145 // reference:: Emitted for locals behind a reference and functions taking `self` by reference.
146 // static:: Emitted for "static" functions, also known as functions that do not take a `self` param, as well as statics and consts.
147 // trait:: Emitted for associated trait items.
148 // unsafe:: Emitted for unsafe operations, like unsafe function calls, as well as the `unsafe` token.
151 // image::https://user-images.githubusercontent.com/48062697/113164457-06cfb980-9239-11eb-819b-0f93e646acf8.png[]
152 // image::https://user-images.githubusercontent.com/48062697/113187625-f7f50100-9250-11eb-825e-91c58f236071.png[]
153 pub(crate) fn highlight(
156 range_to_highlight: Option<TextRange>,
157 syntactic_name_ref_highlighting: bool,
159 let _p = profile::span("highlight");
160 let sema = Semantics::new(db);
162 // Determine the root based on the given range.
163 let (root, range_to_highlight) = {
164 let source_file = sema.parse(file_id);
165 let source_file = source_file.syntax();
166 match range_to_highlight {
168 let node = match source_file.covering_element(range) {
169 NodeOrToken::Node(it) => it,
170 NodeOrToken::Token(it) => it.parent().unwrap_or_else(|| source_file.clone()),
174 None => (source_file.clone(), source_file.text_range()),
178 let mut hl = highlights::Highlights::new(root.text_range());
182 InFile::new(file_id.into(), &root),
183 sema.scope(&root).krate(),
185 syntactic_name_ref_highlighting,
192 sema: &Semantics<RootDatabase>,
193 root: InFile<&SyntaxNode>,
194 krate: Option<hir::Crate>,
195 range_to_highlight: TextRange,
196 syntactic_name_ref_highlighting: bool,
198 let mut bindings_shadow_count: FxHashMap<Name, u32> = FxHashMap::default();
200 let mut current_macro_call: Option<ast::MacroCall> = None;
201 let mut current_attr_call = None;
202 let mut current_macro: Option<ast::Macro> = None;
203 let mut macro_highlighter = MacroHighlighter::default();
204 let mut inside_attribute = false;
206 // Walk all nodes, keeping track of whether we are inside a macro or not.
207 // If in macro, expand it first and highlight the expanded code.
208 for event in root.value.preorder_with_tokens() {
209 let event_range = match &event {
210 WalkEvent::Enter(it) | WalkEvent::Leave(it) => it.text_range(),
213 // Element outside of the viewport, no need to highlight
214 if range_to_highlight.intersect(event_range).is_none() {
218 match event.clone() {
219 WalkEvent::Enter(NodeOrToken::Node(node)) => {
222 ast::MacroCall(mcall) => {
223 if let Some(range) = macro_call_range(&mcall) {
226 highlight: HlTag::Symbol(SymbolKind::Macro).into(),
230 current_macro_call = Some(mcall);
234 macro_highlighter.init();
235 current_macro = Some(mac);
239 if sema.is_attr_macro_call(&item) {
240 current_attr_call = Some(item);
243 ast::Attr(__) => inside_attribute = true,
248 WalkEvent::Leave(NodeOrToken::Node(node)) => {
251 ast::MacroCall(mcall) => {
252 assert_eq!(current_macro_call, Some(mcall));
253 current_macro_call = None;
256 assert_eq!(current_macro, Some(mac));
257 current_macro = None;
258 macro_highlighter = MacroHighlighter::default();
261 if current_attr_call == Some(item) {
262 current_attr_call = None;
265 ast::Attr(__) => inside_attribute = false,
273 let element = match event {
274 WalkEvent::Enter(it) => it,
275 WalkEvent::Leave(it) => {
276 if let Some(node) = it.as_node() {
277 inject::doc_comment(hl, sema, root.with_value(node));
283 let range = element.text_range();
285 if current_macro.is_some() {
286 if let Some(tok) = element.as_token() {
287 macro_highlighter.advance(tok);
291 let descend_token = (current_macro_call.is_some() || current_attr_call.is_some())
292 && element.kind() != COMMENT;
293 let element_to_highlight = if descend_token {
294 // Inside a macro -- expand it first
295 let token = match element.clone().into_token() {
296 Some(it) if current_macro_call.is_some() => {
297 let not_in_tt = it.parent().map_or(true, |it| it.kind() != TOKEN_TREE);
306 let token = sema.descend_into_macros_single(token);
307 match token.parent() {
309 // We only care Name and Name_ref
310 match (token.kind(), parent.kind()) {
311 (T![ident], NAME | NAME_REF) => parent.into(),
312 (T![self] | T![super] | T![crate], NAME_REF) => parent.into(),
313 (INT_NUMBER, NAME_REF) => parent.into(),
317 None => token.into(),
323 if let Some(token) = element.into_token().and_then(ast::String::cast) {
325 if let Some(expanded) = element_to_highlight.as_token() {
326 if inject::ra_fixture(hl, sema, token, expanded.clone()).is_some() {
333 if macro_highlighter.highlight(element_to_highlight.clone()).is_some() {
337 if let Some((mut highlight, binding_hash)) = highlight::element(
340 &mut bindings_shadow_count,
341 syntactic_name_ref_highlighting,
342 element_to_highlight.clone(),
344 if inside_attribute {
345 highlight |= HlMod::Attribute
348 hl.add(HlRange { range, highlight, binding_hash });
351 if let Some(string) = element_to_highlight.into_token().and_then(ast::String::cast) {
352 highlight_format_string(hl, &string, range);
353 // Highlight escape sequences
354 if let Some(char_ranges) = string.char_ranges() {
355 for (piece_range, _) in char_ranges.iter().filter(|(_, char)| char.is_ok()) {
356 if string.text()[piece_range.start().into()..].starts_with('\\') {
358 range: piece_range + range.start(),
359 highlight: HlTag::EscapeSequence.into(),
369 fn macro_call_range(macro_call: &ast::MacroCall) -> Option<TextRange> {
370 let path = macro_call.path()?;
371 let name_ref = path.segment()?.name_ref()?;
373 let range_start = name_ref.syntax().text_range().start();
374 let mut range_end = name_ref.syntax().text_range().end();
375 for sibling in path.syntax().siblings_with_tokens(Direction::Next) {
376 if let T![!] | T![ident] = sibling.kind() {
377 range_end = sibling.text_range().end();
381 Some(TextRange::new(range_start, range_end))