rust/crates/ide/src/syntax_highlighting/highlight.rs

694 lines
25 KiB
Rust

//! Computes color for a single element.
use hir::{AsAssocItem, HasVisibility, Semantics};
use ide_db::{
defs::{Definition, IdentClass, NameClass, NameRefClass},
FxHashMap, RootDatabase, SymbolKind,
};
use syntax::{
ast, match_ast, AstNode, AstToken, NodeOrToken,
SyntaxKind::{self, *},
SyntaxNode, SyntaxToken, T,
};
use crate::{
syntax_highlighting::tags::{HlOperator, HlPunct},
Highlight, HlMod, HlTag,
};
pub(super) fn token(sema: &Semantics<'_, RootDatabase>, token: SyntaxToken) -> Option<Highlight> {
if let Some(comment) = ast::Comment::cast(token.clone()) {
let h = HlTag::Comment;
return Some(match comment.kind().doc {
Some(_) => h | HlMod::Documentation,
None => h.into(),
});
}
let highlight: Highlight = match token.kind() {
STRING | BYTE_STRING => HlTag::StringLiteral.into(),
INT_NUMBER if token.parent_ancestors().nth(1).map(|it| it.kind()) == Some(FIELD_EXPR) => {
SymbolKind::Field.into()
}
INT_NUMBER | FLOAT_NUMBER => HlTag::NumericLiteral.into(),
BYTE => HlTag::ByteLiteral.into(),
CHAR => HlTag::CharLiteral.into(),
IDENT if token.parent().and_then(ast::TokenTree::cast).is_some() => {
// from this point on we are inside a token tree, this only happens for identifiers
// that were not mapped down into macro invocations
HlTag::None.into()
}
p if p.is_punct() => punctuation(sema, token, p),
k if k.is_keyword() => keyword(sema, token, k)?,
_ => return None,
};
Some(highlight)
}
pub(super) fn name_like(
sema: &Semantics<'_, RootDatabase>,
krate: hir::Crate,
bindings_shadow_count: &mut FxHashMap<hir::Name, u32>,
syntactic_name_ref_highlighting: bool,
name_like: ast::NameLike,
) -> Option<(Highlight, Option<u64>)> {
let mut binding_hash = None;
let highlight = match name_like {
ast::NameLike::NameRef(name_ref) => highlight_name_ref(
sema,
krate,
bindings_shadow_count,
&mut binding_hash,
syntactic_name_ref_highlighting,
name_ref,
),
ast::NameLike::Name(name) => {
highlight_name(sema, bindings_shadow_count, &mut binding_hash, krate, name)
}
ast::NameLike::Lifetime(lifetime) => match IdentClass::classify_lifetime(sema, &lifetime) {
Some(IdentClass::NameClass(NameClass::Definition(def))) => {
highlight_def(sema, krate, def) | HlMod::Definition
}
Some(IdentClass::NameRefClass(NameRefClass::Definition(def))) => {
highlight_def(sema, krate, def)
}
// FIXME: Fallback for 'static and '_, as we do not resolve these yet
_ => SymbolKind::LifetimeParam.into(),
},
};
Some((highlight, binding_hash))
}
fn punctuation(
sema: &Semantics<'_, RootDatabase>,
token: SyntaxToken,
kind: SyntaxKind,
) -> Highlight {
let parent = token.parent();
let parent_kind = parent.as_ref().map_or(EOF, SyntaxNode::kind);
match (kind, parent_kind) {
(T![?], TRY_EXPR) => HlTag::Operator(HlOperator::Other) | HlMod::ControlFlow,
(T![&], BIN_EXPR) => HlOperator::Bitwise.into(),
(T![&], REF_EXPR) => {
let h = HlTag::Operator(HlOperator::Other).into();
let is_unsafe = parent
.and_then(ast::RefExpr::cast)
.map(|ref_expr| sema.is_unsafe_ref_expr(&ref_expr));
if let Some(true) = is_unsafe {
h | HlMod::Unsafe
} else {
h
}
}
(T![::] | T![->] | T![=>] | T![..] | T![..=] | T![=] | T![@] | T![.], _) => {
HlOperator::Other.into()
}
(T![!], MACRO_CALL | MACRO_RULES) => HlPunct::MacroBang.into(),
(T![!], NEVER_TYPE) => HlTag::BuiltinType.into(),
(T![!], PREFIX_EXPR) => HlOperator::Logical.into(),
(T![*], PTR_TYPE) => HlTag::Keyword.into(),
(T![*], PREFIX_EXPR) => {
let is_raw_ptr = (|| {
let prefix_expr = parent.and_then(ast::PrefixExpr::cast)?;
let expr = prefix_expr.expr()?;
sema.type_of_expr(&expr)?.original.is_raw_ptr().then_some(())
})();
if let Some(()) = is_raw_ptr {
HlTag::Operator(HlOperator::Other) | HlMod::Unsafe
} else {
HlOperator::Other.into()
}
}
(T![-], PREFIX_EXPR) => {
let prefix_expr = parent.and_then(ast::PrefixExpr::cast).and_then(|e| e.expr());
match prefix_expr {
Some(ast::Expr::Literal(_)) => HlTag::NumericLiteral,
_ => HlTag::Operator(HlOperator::Other),
}
.into()
}
(T![+] | T![-] | T![*] | T![/] | T![%], BIN_EXPR) => HlOperator::Arithmetic.into(),
(T![+=] | T![-=] | T![*=] | T![/=] | T![%=], BIN_EXPR) => {
Highlight::from(HlOperator::Arithmetic) | HlMod::Mutable
}
(T![|] | T![&] | T![^] | T![>>] | T![<<], BIN_EXPR) => HlOperator::Bitwise.into(),
(T![|=] | T![&=] | T![^=] | T![>>=] | T![<<=], BIN_EXPR) => {
Highlight::from(HlOperator::Bitwise) | HlMod::Mutable
}
(T![&&] | T![||], BIN_EXPR) => HlOperator::Logical.into(),
(T![>] | T![<] | T![==] | T![>=] | T![<=] | T![!=], BIN_EXPR) => {
HlOperator::Comparison.into()
}
(_, ATTR) => HlTag::AttributeBracket.into(),
(kind, _) => match kind {
T!['['] | T![']'] => HlPunct::Bracket,
T!['{'] | T!['}'] => HlPunct::Brace,
T!['('] | T![')'] => HlPunct::Parenthesis,
T![<] | T![>] => HlPunct::Angle,
T![,] => HlPunct::Comma,
T![:] => HlPunct::Colon,
T![;] => HlPunct::Semi,
T![.] => HlPunct::Dot,
_ => HlPunct::Other,
}
.into(),
}
}
fn keyword(
sema: &Semantics<'_, RootDatabase>,
token: SyntaxToken,
kind: SyntaxKind,
) -> Option<Highlight> {
let h = Highlight::new(HlTag::Keyword);
let h = match kind {
T![await] => h | HlMod::Async | HlMod::ControlFlow,
T![async] => h | HlMod::Async,
T![break]
| T![continue]
| T![else]
| T![if]
| T![in]
| T![loop]
| T![match]
| T![return]
| T![while]
| T![yield] => h | HlMod::ControlFlow,
T![do] | T![yeet] if parent_matches::<ast::YeetExpr>(&token) => h | HlMod::ControlFlow,
T![for] if parent_matches::<ast::ForExpr>(&token) => h | HlMod::ControlFlow,
T![unsafe] => h | HlMod::Unsafe,
T![true] | T![false] => HlTag::BoolLiteral.into(),
// crate is handled just as a token if it's in an `extern crate`
T![crate] if parent_matches::<ast::ExternCrate>(&token) => h,
// self, crate, super and `Self` are handled as either a Name or NameRef already, unless they
// are inside unmapped token trees
T![self] | T![crate] | T![super] | T![Self] if parent_matches::<ast::NameRef>(&token) => {
return None
}
T![self] if parent_matches::<ast::Name>(&token) => return None,
T![ref] => match token.parent().and_then(ast::IdentPat::cast) {
Some(ident) if sema.is_unsafe_ident_pat(&ident) => h | HlMod::Unsafe,
_ => h,
},
_ => h,
};
Some(h)
}
fn highlight_name_ref(
sema: &Semantics<'_, RootDatabase>,
krate: hir::Crate,
bindings_shadow_count: &mut FxHashMap<hir::Name, u32>,
binding_hash: &mut Option<u64>,
syntactic_name_ref_highlighting: bool,
name_ref: ast::NameRef,
) -> Highlight {
let db = sema.db;
if let Some(res) = highlight_method_call_by_name_ref(sema, krate, &name_ref) {
return res;
}
let name_class = match NameRefClass::classify(sema, &name_ref) {
Some(name_kind) => name_kind,
None if syntactic_name_ref_highlighting => {
return highlight_name_ref_by_syntax(name_ref, sema, krate)
}
// FIXME: This is required for helper attributes used by proc-macros, as those do not map down
// to anything when used.
// We can fix this for derive attributes since derive helpers are recorded, but not for
// general attributes.
None if name_ref.syntax().ancestors().any(|it| it.kind() == ATTR)
&& !sema.hir_file_for(name_ref.syntax()).is_derive_attr_pseudo_expansion(sema.db) =>
{
return HlTag::Symbol(SymbolKind::Attribute).into();
}
None => return HlTag::UnresolvedReference.into(),
};
let mut h = match name_class {
NameRefClass::Definition(def) => {
if let Definition::Local(local) = &def {
let name = local.name(db);
let shadow_count = bindings_shadow_count.entry(name.clone()).or_default();
*binding_hash = Some(calc_binding_hash(&name, *shadow_count))
};
let mut h = highlight_def(sema, krate, def);
match def {
Definition::Local(local) if is_consumed_lvalue(name_ref.syntax(), &local, db) => {
h |= HlMod::Consuming;
}
Definition::Trait(trait_) if trait_.is_unsafe(db) => {
if ast::Impl::for_trait_name_ref(&name_ref)
.map_or(false, |impl_| impl_.unsafe_token().is_some())
{
h |= HlMod::Unsafe;
}
}
Definition::Field(field) => {
if let Some(parent) = name_ref.syntax().parent() {
if matches!(parent.kind(), FIELD_EXPR | RECORD_PAT_FIELD) {
if let hir::VariantDef::Union(_) = field.parent_def(db) {
h |= HlMod::Unsafe;
}
}
}
}
Definition::Macro(_) => {
if let Some(macro_call) =
ide_db::syntax_helpers::node_ext::full_path_of_name_ref(&name_ref)
.and_then(|it| it.syntax().parent().and_then(ast::MacroCall::cast))
{
if sema.is_unsafe_macro_call(&macro_call) {
h |= HlMod::Unsafe;
}
}
}
_ => (),
}
h
}
NameRefClass::FieldShorthand { .. } => SymbolKind::Field.into(),
};
h.tag = match name_ref.token_kind() {
T![Self] => HlTag::Symbol(SymbolKind::SelfType),
T![self] => HlTag::Symbol(SymbolKind::SelfParam),
T![super] | T![crate] => HlTag::Keyword,
_ => h.tag,
};
h
}
fn highlight_name(
sema: &Semantics<'_, RootDatabase>,
bindings_shadow_count: &mut FxHashMap<hir::Name, u32>,
binding_hash: &mut Option<u64>,
krate: hir::Crate,
name: ast::Name,
) -> Highlight {
let name_kind = NameClass::classify(sema, &name);
if let Some(NameClass::Definition(Definition::Local(local))) = &name_kind {
let name = local.name(sema.db);
let shadow_count = bindings_shadow_count.entry(name.clone()).or_default();
*shadow_count += 1;
*binding_hash = Some(calc_binding_hash(&name, *shadow_count))
};
match name_kind {
Some(NameClass::Definition(def)) => {
let mut h = highlight_def(sema, krate, def) | HlMod::Definition;
if let Definition::Trait(trait_) = &def {
if trait_.is_unsafe(sema.db) {
h |= HlMod::Unsafe;
}
}
h
}
Some(NameClass::ConstReference(def)) => highlight_def(sema, krate, def),
Some(NameClass::PatFieldShorthand { field_ref, .. }) => {
let mut h = HlTag::Symbol(SymbolKind::Field).into();
if let hir::VariantDef::Union(_) = field_ref.parent_def(sema.db) {
h |= HlMod::Unsafe;
}
h
}
None => highlight_name_by_syntax(name) | HlMod::Definition,
}
}
fn calc_binding_hash(name: &hir::Name, shadow_count: u32) -> u64 {
fn hash<T: std::hash::Hash + std::fmt::Debug>(x: T) -> u64 {
use std::{collections::hash_map::DefaultHasher, hash::Hasher};
let mut hasher = DefaultHasher::new();
x.hash(&mut hasher);
hasher.finish()
}
hash((name, shadow_count))
}
fn highlight_def(
sema: &Semantics<'_, RootDatabase>,
krate: hir::Crate,
def: Definition,
) -> Highlight {
let db = sema.db;
let mut h = match def {
Definition::Macro(m) => Highlight::new(HlTag::Symbol(m.kind(sema.db).into())),
Definition::Field(_) => Highlight::new(HlTag::Symbol(SymbolKind::Field)),
Definition::Module(module) => {
let mut h = Highlight::new(HlTag::Symbol(SymbolKind::Module));
if module.is_crate_root(db) {
h |= HlMod::CrateRoot;
}
h
}
Definition::Function(func) => {
let mut h = Highlight::new(HlTag::Symbol(SymbolKind::Function));
if let Some(item) = func.as_assoc_item(db) {
h |= HlMod::Associated;
match func.self_param(db) {
Some(sp) => match sp.access(db) {
hir::Access::Exclusive => {
h |= HlMod::Mutable;
h |= HlMod::Reference;
}
hir::Access::Shared => h |= HlMod::Reference,
hir::Access::Owned => h |= HlMod::Consuming,
},
None => h |= HlMod::Static,
}
match item.container(db) {
hir::AssocItemContainer::Impl(i) => {
if i.trait_(db).is_some() {
h |= HlMod::Trait;
}
}
hir::AssocItemContainer::Trait(_t) => {
h |= HlMod::Trait;
}
}
}
if func.is_unsafe_to_call(db) {
h |= HlMod::Unsafe;
}
if func.is_async(db) {
h |= HlMod::Async;
}
h
}
Definition::Adt(adt) => {
let h = match adt {
hir::Adt::Struct(_) => HlTag::Symbol(SymbolKind::Struct),
hir::Adt::Enum(_) => HlTag::Symbol(SymbolKind::Enum),
hir::Adt::Union(_) => HlTag::Symbol(SymbolKind::Union),
};
Highlight::new(h)
}
Definition::Variant(_) => Highlight::new(HlTag::Symbol(SymbolKind::Variant)),
Definition::Const(konst) => {
let mut h = Highlight::new(HlTag::Symbol(SymbolKind::Const));
if let Some(item) = konst.as_assoc_item(db) {
h |= HlMod::Associated;
match item.container(db) {
hir::AssocItemContainer::Impl(i) => {
if i.trait_(db).is_some() {
h |= HlMod::Trait;
}
}
hir::AssocItemContainer::Trait(_t) => {
h |= HlMod::Trait;
}
}
}
h
}
Definition::Trait(_) => Highlight::new(HlTag::Symbol(SymbolKind::Trait)),
Definition::TraitAlias(_) => Highlight::new(HlTag::Symbol(SymbolKind::TraitAlias)),
Definition::TypeAlias(type_) => {
let mut h = Highlight::new(HlTag::Symbol(SymbolKind::TypeAlias));
if let Some(item) = type_.as_assoc_item(db) {
h |= HlMod::Associated;
match item.container(db) {
hir::AssocItemContainer::Impl(i) => {
if i.trait_(db).is_some() {
h |= HlMod::Trait;
}
}
hir::AssocItemContainer::Trait(_t) => {
h |= HlMod::Trait;
}
}
}
h
}
Definition::BuiltinType(_) => Highlight::new(HlTag::BuiltinType),
Definition::Static(s) => {
let mut h = Highlight::new(HlTag::Symbol(SymbolKind::Static));
if s.is_mut(db) {
h |= HlMod::Mutable;
h |= HlMod::Unsafe;
}
h
}
Definition::SelfType(_) => Highlight::new(HlTag::Symbol(SymbolKind::Impl)),
Definition::GenericParam(it) => match it {
hir::GenericParam::TypeParam(_) => Highlight::new(HlTag::Symbol(SymbolKind::TypeParam)),
hir::GenericParam::ConstParam(_) => {
Highlight::new(HlTag::Symbol(SymbolKind::ConstParam))
}
hir::GenericParam::LifetimeParam(_) => {
Highlight::new(HlTag::Symbol(SymbolKind::LifetimeParam))
}
},
Definition::Local(local) => {
let tag = if local.is_self(db) {
HlTag::Symbol(SymbolKind::SelfParam)
} else if local.is_param(db) {
HlTag::Symbol(SymbolKind::ValueParam)
} else {
HlTag::Symbol(SymbolKind::Local)
};
let mut h = Highlight::new(tag);
let ty = local.ty(db);
if local.is_mut(db) || ty.is_mutable_reference() {
h |= HlMod::Mutable;
}
if local.is_ref(db) || ty.is_reference() {
h |= HlMod::Reference;
}
if ty.as_callable(db).is_some() || ty.impls_fnonce(db) {
h |= HlMod::Callable;
}
h
}
Definition::Label(_) => Highlight::new(HlTag::Symbol(SymbolKind::Label)),
Definition::BuiltinAttr(_) => Highlight::new(HlTag::Symbol(SymbolKind::BuiltinAttr)),
Definition::ToolModule(_) => Highlight::new(HlTag::Symbol(SymbolKind::ToolModule)),
Definition::DeriveHelper(_) => Highlight::new(HlTag::Symbol(SymbolKind::DeriveHelper)),
};
let def_crate = def.krate(db);
let is_from_other_crate = def_crate != Some(krate);
let is_from_builtin_crate = def_crate.map_or(false, |def_crate| def_crate.is_builtin(db));
let is_builtin_type = matches!(def, Definition::BuiltinType(_));
let is_public = def.visibility(db) == Some(hir::Visibility::Public);
match (is_from_other_crate, is_builtin_type, is_public) {
(true, false, _) => h |= HlMod::Library,
(false, _, true) => h |= HlMod::Public,
_ => {}
}
if is_from_builtin_crate {
h |= HlMod::DefaultLibrary;
}
h
}
fn highlight_method_call_by_name_ref(
sema: &Semantics<'_, RootDatabase>,
krate: hir::Crate,
name_ref: &ast::NameRef,
) -> Option<Highlight> {
let mc = name_ref.syntax().parent().and_then(ast::MethodCallExpr::cast)?;
highlight_method_call(sema, krate, &mc)
}
fn highlight_method_call(
sema: &Semantics<'_, RootDatabase>,
krate: hir::Crate,
method_call: &ast::MethodCallExpr,
) -> Option<Highlight> {
let func = sema.resolve_method_call(method_call)?;
let mut h = SymbolKind::Function.into();
h |= HlMod::Associated;
if func.is_unsafe_to_call(sema.db) || sema.is_unsafe_method_call(method_call) {
h |= HlMod::Unsafe;
}
if func.is_async(sema.db) {
h |= HlMod::Async;
}
if func
.as_assoc_item(sema.db)
.and_then(|it| it.containing_trait_or_trait_impl(sema.db))
.is_some()
{
h |= HlMod::Trait;
}
let def_crate = func.module(sema.db).krate();
let is_from_other_crate = def_crate != krate;
let is_from_builtin_crate = def_crate.is_builtin(sema.db);
let is_public = func.visibility(sema.db) == hir::Visibility::Public;
if is_from_other_crate {
h |= HlMod::Library;
} else if is_public {
h |= HlMod::Public;
}
if is_from_builtin_crate {
h |= HlMod::DefaultLibrary;
}
if let Some(self_param) = func.self_param(sema.db) {
match self_param.access(sema.db) {
hir::Access::Shared => h |= HlMod::Reference,
hir::Access::Exclusive => {
h |= HlMod::Mutable;
h |= HlMod::Reference;
}
hir::Access::Owned => {
if let Some(receiver_ty) =
method_call.receiver().and_then(|it| sema.type_of_expr(&it))
{
if !receiver_ty.adjusted().is_copy(sema.db) {
h |= HlMod::Consuming
}
}
}
}
}
Some(h)
}
fn highlight_name_by_syntax(name: ast::Name) -> Highlight {
let default = HlTag::UnresolvedReference;
let parent = match name.syntax().parent() {
Some(it) => it,
_ => return default.into(),
};
let tag = match parent.kind() {
STRUCT => SymbolKind::Struct,
ENUM => SymbolKind::Enum,
VARIANT => SymbolKind::Variant,
UNION => SymbolKind::Union,
TRAIT => SymbolKind::Trait,
TYPE_ALIAS => SymbolKind::TypeAlias,
TYPE_PARAM => SymbolKind::TypeParam,
RECORD_FIELD => SymbolKind::Field,
MODULE => SymbolKind::Module,
FN => SymbolKind::Function,
CONST => SymbolKind::Const,
STATIC => SymbolKind::Static,
IDENT_PAT => SymbolKind::Local,
_ => return default.into(),
};
tag.into()
}
fn highlight_name_ref_by_syntax(
name: ast::NameRef,
sema: &Semantics<'_, RootDatabase>,
krate: hir::Crate,
) -> Highlight {
let default = HlTag::UnresolvedReference;
let parent = match name.syntax().parent() {
Some(it) => it,
_ => return default.into(),
};
match parent.kind() {
METHOD_CALL_EXPR => ast::MethodCallExpr::cast(parent)
.and_then(|it| highlight_method_call(sema, krate, &it))
.unwrap_or_else(|| SymbolKind::Function.into()),
FIELD_EXPR => {
let h = HlTag::Symbol(SymbolKind::Field);
let is_union = ast::FieldExpr::cast(parent)
.and_then(|field_expr| sema.resolve_field(&field_expr))
.map_or(false, |field| {
matches!(field.parent_def(sema.db), hir::VariantDef::Union(_))
});
if is_union {
h | HlMod::Unsafe
} else {
h.into()
}
}
PATH_SEGMENT => {
let name_based_fallback = || {
if name.text().chars().next().unwrap_or_default().is_uppercase() {
SymbolKind::Struct.into()
} else {
SymbolKind::Module.into()
}
};
let path = match parent.parent().and_then(ast::Path::cast) {
Some(it) => it,
_ => return name_based_fallback(),
};
let expr = match path.syntax().parent() {
Some(parent) => match_ast! {
match parent {
ast::PathExpr(path) => path,
ast::MacroCall(_) => return SymbolKind::Macro.into(),
_ => return name_based_fallback(),
}
},
// within path, decide whether it is module or adt by checking for uppercase name
None => return name_based_fallback(),
};
let parent = match expr.syntax().parent() {
Some(it) => it,
None => return default.into(),
};
match parent.kind() {
CALL_EXPR => SymbolKind::Function.into(),
_ => if name.text().chars().next().unwrap_or_default().is_uppercase() {
SymbolKind::Struct
} else {
SymbolKind::Const
}
.into(),
}
}
_ => default.into(),
}
}
fn is_consumed_lvalue(node: &SyntaxNode, local: &hir::Local, db: &RootDatabase) -> bool {
// When lvalues are passed as arguments and they're not Copy, then mark them as Consuming.
parents_match(node.clone().into(), &[PATH_SEGMENT, PATH, PATH_EXPR, ARG_LIST])
&& !local.ty(db).is_copy(db)
}
/// Returns true if the parent nodes of `node` all match the `SyntaxKind`s in `kinds` exactly.
fn parents_match(mut node: NodeOrToken<SyntaxNode, SyntaxToken>, mut kinds: &[SyntaxKind]) -> bool {
while let (Some(parent), [kind, rest @ ..]) = (node.parent(), kinds) {
if parent.kind() != *kind {
return false;
}
node = parent.into();
kinds = rest;
}
// Only true if we matched all expected kinds
kinds.is_empty()
}
fn parent_matches<N: AstNode>(token: &SyntaxToken) -> bool {
token.parent().map_or(false, |it| N::can_cast(it.kind()))
}