rust/crates/ide/src/syntax_highlighting.rs
2022-07-22 17:29:03 +02:00

442 lines
18 KiB
Rust

pub(crate) mod tags;
mod highlights;
mod injector;
mod highlight;
mod format;
mod macro_;
mod inject;
mod escape;
mod html;
#[cfg(test)]
mod tests;
use hir::{InFile, Name, Semantics};
use ide_db::{FxHashMap, RootDatabase};
use syntax::{
ast, AstNode, AstToken, NodeOrToken, SyntaxKind::*, SyntaxNode, TextRange, WalkEvent, T,
};
use crate::{
syntax_highlighting::{
escape::highlight_escape_string, format::highlight_format_string, highlights::Highlights,
macro_::MacroHighlighter, tags::Highlight,
},
FileId, HlMod, HlTag,
};
pub(crate) use html::highlight_as_html;
#[derive(Debug, Clone, Copy)]
pub struct HlRange {
pub range: TextRange,
pub highlight: Highlight,
pub binding_hash: Option<u64>,
}
// 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 a 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.
//
//
// .Token Tags
//
// Rust-analyzer currently emits the following token tags:
//
// - For items:
// +
// [horizontal]
// attribute:: Emitted for attribute macros.
// enum:: Emitted for enums.
// function:: Emitted for free-standing functions.
// derive:: Emitted for derive macros.
// macro:: Emitted for function-like macros.
// method:: Emitted for associated functions, also knowns as methods.
// namespace:: Emitted for modules.
// struct:: Emitted for structs.
// trait:: Emitted for traits.
// typeAlias:: Emitted for type aliases and `Self` in `impl`s.
// union:: Emitted for unions.
//
// - For literals:
// +
// [horizontal]
// boolean:: Emitted for the boolean literals `true` and `false`.
// character:: Emitted for character literals.
// number:: Emitted for numeric literals.
// string:: Emitted for string literals.
// escapeSequence:: Emitted for escaped sequences inside strings like `\n`.
// formatSpecifier:: Emitted for format specifiers `{:?}` in `format!`-like macros.
//
// - For operators:
// +
// [horizontal]
// operator:: Emitted for general operators.
// arithmetic:: Emitted for the arithmetic operators `+`, `-`, `*`, `/`, `+=`, `-=`, `*=`, `/=`.
// bitwise:: Emitted for the bitwise operators `|`, `&`, `!`, `^`, `|=`, `&=`, `^=`.
// comparison:: Emitted for the comparison operators `>`, `<`, `==`, `>=`, `<=`, `!=`.
// logical:: Emitted for the logical operators `||`, `&&`, `!`.
//
// - For punctuation:
// +
// [horizontal]
// punctuation:: Emitted for general punctuation.
// attributeBracket:: Emitted for attribute invocation brackets, that is the `#[` and `]` tokens.
// angle:: Emitted for `<>` angle brackets.
// brace:: Emitted for `{}` braces.
// bracket:: Emitted for `[]` brackets.
// parenthesis:: Emitted for `()` parentheses.
// colon:: Emitted for the `:` token.
// comma:: Emitted for the `,` token.
// dot:: Emitted for the `.` token.
// semi:: Emitted for the `;` token.
// macroBang:: Emitted for the `!` token in macro calls.
//
// //-
//
// [horizontal]
// builtinAttribute:: Emitted for names to builtin attributes in attribute path, the `repr` in `#[repr(u8)]` for example.
// builtinType:: Emitted for builtin types like `u32`, `str` and `f32`.
// comment:: Emitted for comments.
// constParameter:: Emitted for const parameters.
// enumMember:: Emitted for enum variants.
// generic:: Emitted for generic tokens that have no mapping.
// keyword:: Emitted for keywords.
// label:: Emitted for labels.
// lifetime:: Emitted for lifetimes.
// parameter:: Emitted for non-self function parameters.
// property:: Emitted for struct and union fields.
// selfKeyword:: Emitted for the self function parameter and self path-specifier.
// selfTypeKeyword:: Emitted for the Self type parameter.
// toolModule:: Emitted for tool modules.
// typeParameter:: Emitted for type parameters.
// unresolvedReference:: Emitted for unresolved references, names that rust-analyzer can't find the definition of.
// variable:: Emitted for locals, constants and statics.
//
//
// .Token Modifiers
//
// Token modifiers allow to style some elements in the source code more precisely.
//
// Rust-analyzer currently emits the following token modifiers:
//
// [horizontal]
// async:: Emitted for async functions and the `async` and `await` keywords.
// attribute:: Emitted for tokens inside attributes.
// callable:: Emitted for locals whose types implements one of the `Fn*` traits.
// constant:: Emitted for consts.
// consuming:: Emitted for locals that are being consumed when use in a function call.
// controlFlow:: Emitted for control-flow related tokens, this includes the `?` operator.
// crateRoot:: Emitted for crate names, like `serde` and `crate`.
// declaration:: Emitted for names of definitions, like `foo` in `fn foo() {}`.
// defaultLibrary:: Emitted for items from built-in crates (std, core, alloc, test and proc_macro).
// documentation:: Emitted for documentation comments.
// injected:: Emitted for doc-string injected highlighting like rust source blocks in documentation.
// intraDocLink:: Emitted for intra doc links in doc-strings.
// library:: Emitted for items that are defined outside of the current crate.
// mutable:: Emitted for mutable locals and statics as well as functions taking `&mut self`.
// public:: Emitted for items that are from the current crate and are `pub`.
// reference:: Emitted for locals behind a reference and functions taking `self` by reference.
// static:: Emitted for "static" functions, also known as functions that do not take a `self` param, as well as statics and consts.
// trait:: Emitted for associated trait items.
// unsafe:: Emitted for unsafe operations, like unsafe function calls, as well as the `unsafe` token.
//
//
// image::https://user-images.githubusercontent.com/48062697/113164457-06cfb980-9239-11eb-819b-0f93e646acf8.png[]
// image::https://user-images.githubusercontent.com/48062697/113187625-f7f50100-9250-11eb-825e-91c58f236071.png[]
pub(crate) fn highlight(
db: &RootDatabase,
file_id: FileId,
range_to_highlight: Option<TextRange>,
syntactic_name_ref_highlighting: bool,
) -> Vec<HlRange> {
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);
let source_file = source_file.syntax();
match range_to_highlight {
Some(range) => {
let node = match source_file.covering_element(range) {
NodeOrToken::Node(it) => it,
NodeOrToken::Token(it) => it.parent().unwrap_or_else(|| source_file.clone()),
};
(node, range)
}
None => (source_file.clone(), source_file.text_range()),
}
};
let mut hl = highlights::Highlights::new(root.text_range());
let krate = match sema.scope(&root) {
Some(it) => it.krate(),
None => return hl.to_vec(),
};
traverse(
&mut hl,
&sema,
file_id,
&root,
krate,
range_to_highlight,
syntactic_name_ref_highlighting,
);
hl.to_vec()
}
fn traverse(
hl: &mut Highlights,
sema: &Semantics<'_, RootDatabase>,
file_id: FileId,
root: &SyntaxNode,
krate: hir::Crate,
range_to_highlight: TextRange,
syntactic_name_ref_highlighting: bool,
) {
let is_unlinked = sema.to_module_def(file_id).is_none();
let mut bindings_shadow_count: FxHashMap<Name, u32> = FxHashMap::default();
enum AttrOrDerive {
Attr(ast::Item),
Derive(ast::Item),
}
impl AttrOrDerive {
fn item(&self) -> &ast::Item {
match self {
AttrOrDerive::Attr(item) | AttrOrDerive::Derive(item) => item,
}
}
}
let mut tt_level = 0;
let mut attr_or_derive_item = None;
let mut current_macro: Option<ast::Macro> = None;
let mut macro_highlighter = MacroHighlighter::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() {
use WalkEvent::{Enter, Leave};
let range = match &event {
Enter(it) | Leave(it) => it.text_range(),
};
// Element outside of the viewport, no need to highlight
if range_to_highlight.intersect(range).is_none() {
continue;
}
// set macro and attribute highlighting states
match event.clone() {
Enter(NodeOrToken::Node(node)) if ast::TokenTree::can_cast(node.kind()) => {
tt_level += 1;
}
Leave(NodeOrToken::Node(node)) if ast::TokenTree::can_cast(node.kind()) => {
tt_level -= 1;
}
Enter(NodeOrToken::Node(node)) if ast::Attr::can_cast(node.kind()) => {
inside_attribute = true
}
Leave(NodeOrToken::Node(node)) if ast::Attr::can_cast(node.kind()) => {
inside_attribute = false
}
Enter(NodeOrToken::Node(node)) if ast::Item::can_cast(node.kind()) => {
match ast::Item::cast(node.clone()) {
Some(ast::Item::MacroRules(mac)) => {
macro_highlighter.init();
current_macro = Some(mac.into());
continue;
}
Some(ast::Item::MacroDef(mac)) => {
macro_highlighter.init();
current_macro = Some(mac.into());
continue;
}
Some(item) => {
if matches!(node.kind(), FN | CONST | STATIC) {
bindings_shadow_count.clear();
}
if attr_or_derive_item.is_none() {
if sema.is_attr_macro_call(&item) {
attr_or_derive_item = Some(AttrOrDerive::Attr(item));
} else {
let adt = match item {
ast::Item::Enum(it) => Some(ast::Adt::Enum(it)),
ast::Item::Struct(it) => Some(ast::Adt::Struct(it)),
ast::Item::Union(it) => Some(ast::Adt::Union(it)),
_ => None,
};
match adt {
Some(adt) if sema.is_derive_annotated(&adt) => {
attr_or_derive_item =
Some(AttrOrDerive::Derive(ast::Item::from(adt)));
}
_ => (),
}
}
}
}
_ => (),
}
}
Leave(NodeOrToken::Node(node)) if ast::Item::can_cast(node.kind()) => {
match ast::Item::cast(node.clone()) {
Some(ast::Item::MacroRules(mac)) => {
assert_eq!(current_macro, Some(mac.into()));
current_macro = None;
macro_highlighter = MacroHighlighter::default();
}
Some(ast::Item::MacroDef(mac)) => {
assert_eq!(current_macro, Some(mac.into()));
current_macro = None;
macro_highlighter = MacroHighlighter::default();
}
Some(item)
if attr_or_derive_item.as_ref().map_or(false, |it| *it.item() == item) =>
{
attr_or_derive_item = None;
}
_ => (),
}
}
_ => (),
}
let element = match event {
Enter(NodeOrToken::Token(tok)) if tok.kind() == WHITESPACE => continue,
Enter(it) => it,
Leave(NodeOrToken::Token(_)) => continue,
Leave(NodeOrToken::Node(node)) => {
// Doc comment highlighting injection, we do this when leaving the node
// so that we overwrite the highlighting of the doc comment itself.
inject::doc_comment(hl, sema, InFile::new(file_id.into(), &node));
continue;
}
};
if current_macro.is_some() {
if let Some(tok) = element.as_token() {
macro_highlighter.advance(tok);
}
}
let element = match element.clone() {
NodeOrToken::Node(n) => match ast::NameLike::cast(n) {
Some(n) => NodeOrToken::Node(n),
None => continue,
},
NodeOrToken::Token(t) => NodeOrToken::Token(t),
};
let token = element.as_token().cloned();
// Descending tokens into macros is expensive even if no descending occurs, so make sure
// that we actually are in a position where descending is possible.
let in_macro = tt_level > 0
|| match attr_or_derive_item {
Some(AttrOrDerive::Attr(_)) => true,
Some(AttrOrDerive::Derive(_)) => inside_attribute,
None => false,
};
let descended_element = if in_macro {
// Attempt to descend tokens into macro-calls.
match element {
NodeOrToken::Token(token) if token.kind() != COMMENT => {
let token = match attr_or_derive_item {
Some(AttrOrDerive::Attr(_)) => {
sema.descend_into_macros_with_kind_preference(token)
}
Some(AttrOrDerive::Derive(_)) | None => {
sema.descend_into_macros_single(token)
}
};
match token.parent().and_then(ast::NameLike::cast) {
// Remap the token into the wrapping single token nodes
Some(parent) => match (token.kind(), parent.syntax().kind()) {
(T![self] | T![ident], NAME | NAME_REF) => NodeOrToken::Node(parent),
(T![self] | T![super] | T![crate] | T![Self], NAME_REF) => {
NodeOrToken::Node(parent)
}
(INT_NUMBER, NAME_REF) => NodeOrToken::Node(parent),
(LIFETIME_IDENT, LIFETIME) => NodeOrToken::Node(parent),
_ => NodeOrToken::Token(token),
},
None => NodeOrToken::Token(token),
}
}
e => e,
}
} else {
element
};
// FIXME: do proper macro def highlighting https://github.com/rust-lang/rust-analyzer/issues/6232
// Skip metavariables from being highlighted to prevent keyword highlighting in them
if descended_element.as_token().and_then(|t| macro_highlighter.highlight(t)).is_some() {
continue;
}
// string highlight injections, note this does not use the descended element as proc-macros
// can rewrite string literals which invalidates our indices
if let (Some(token), Some(descended_token)) = (token, descended_element.as_token()) {
if ast::String::can_cast(token.kind()) && ast::String::can_cast(descended_token.kind())
{
let string = ast::String::cast(token);
let string_to_highlight = ast::String::cast(descended_token.clone());
if let Some((string, expanded_string)) = string.zip(string_to_highlight) {
if string.is_raw() {
if inject::ra_fixture(hl, sema, &string, &expanded_string).is_some() {
continue;
}
}
highlight_format_string(hl, &string, &expanded_string, range);
highlight_escape_string(hl, &string, range.start());
}
} else if ast::ByteString::can_cast(token.kind())
&& ast::ByteString::can_cast(descended_token.kind())
{
if let Some(byte_string) = ast::ByteString::cast(token) {
highlight_escape_string(hl, &byte_string, range.start());
}
}
}
let element = match descended_element {
NodeOrToken::Node(name_like) => highlight::name_like(
sema,
krate,
&mut bindings_shadow_count,
syntactic_name_ref_highlighting,
name_like,
),
NodeOrToken::Token(token) => highlight::token(sema, token).zip(Some(None)),
};
if let Some((mut highlight, binding_hash)) = element {
if is_unlinked && highlight.tag == HlTag::UnresolvedReference {
// do not emit unresolved references if the file is unlinked
// let the editor do its highlighting for these tokens instead
continue;
}
if inside_attribute {
highlight |= HlMod::Attribute
}
hl.add(HlRange { range, highlight, binding_hash });
}
}
}