internal: Handle macro calls better in highlighting

Author: Veykril

crates/ide/src/syntax_highlighting.rs

@@ -13,11 +13,11 @@ mod html;
 mod tests;
 
 use hir::{InFile, Name, Semantics};
-use ide_db::{RootDatabase, SymbolKind};
+use ide_db::RootDatabase;
 use rustc_hash::FxHashMap;
 use syntax::{
  ast::{self, HasFormatSpecifier},
- match_ast, AstNode, AstToken, Direction, NodeOrToken,
+ AstNode, AstToken, NodeOrToken,
  SyntaxKind::*,
  SyntaxNode, TextRange, WalkEvent, T,
 };
@@ -100,7 +100,8 @@ pub struct HlRange {
 // colon:: Emitted for the `:` token.
 // comma:: Emitted for the `,` token.
 // dot:: Emitted for the `.` token.
-// Semi:: Emitted for the `;` token.
+// semi:: Emitted for the `;` token.
+// macroBang:: Emitted for the `!` token in macro calls.
 //
 // //-
 //
@@ -209,107 +210,94 @@ fn traverse(
  // 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.value.preorder_with_tokens() {
- let event_range = match &event {
+ let range = match &event {
  WalkEvent::Enter(it) | WalkEvent::Leave(it) => it.text_range(),
  };
 
  // Element outside of the viewport, no need to highlight
- if range_to_highlight.intersect(event_range).is_none() {
+ if range_to_highlight.intersect(range).is_none() {
  continue;
  }
 
+ // set macro and attribute highlighting states
  match event.clone() {
- WalkEvent::Enter(NodeOrToken::Node(node)) => {
- match_ast! {
- match node {
- ast::MacroCall(mcall) => {
- if let Some(range) = macro_call_range(&mcall) {
- hl.add(HlRange {
- range,
- highlight: HlTag::Symbol(SymbolKind::Macro).into(),
- binding_hash: None,
- });
- }
- current_macro_call = Some(mcall);
- continue;
- },
- ast::Macro(mac) => {
- macro_highlighter.init();
- current_macro = Some(mac);
- continue;
- },
- ast::Item(item) => {
- if sema.is_attr_macro_call(&item) {
- current_attr_call = Some(item);
- }
- },
- ast::Attr(__) => inside_attribute = true,
- _ => ()
- }
+ WalkEvent::Enter(NodeOrToken::Node(node)) => match ast::Item::cast(node.clone()) {
+ Some(ast::Item::MacroCall(mcall)) => {
+ current_macro_call = Some(mcall);
+ continue;
  }
- }
- WalkEvent::Leave(NodeOrToken::Node(node)) => {
- match_ast! {
- match node {
- ast::MacroCall(mcall) => {
- assert_eq!(current_macro_call, Some(mcall));
- current_macro_call = None;
- },
- ast::Macro(mac) => {
- assert_eq!(current_macro, Some(mac));
- current_macro = None;
- macro_highlighter = MacroHighlighter::default();
- },
- ast::Item(item) => {
- if current_attr_call == Some(item) {
- current_attr_call = None;
- }
- },
- ast::Attr(__) => inside_attribute = false,
- _ => ()
- }
+ 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 sema.is_attr_macro_call(&item) => current_attr_call = Some(item),
+ None if ast::Attr::can_cast(node.kind()) => inside_attribute = true,
+ _ => (),
+ },
+ WalkEvent::Leave(NodeOrToken::Node(node)) => match ast::Item::cast(node.clone()) {
+ Some(ast::Item::MacroCall(mcall)) => {
+ assert_eq!(current_macro_call, Some(mcall));
+ current_macro_call = None;
+ }
+ 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 current_attr_call.as_ref().map_or(false, |it| *it == item) => {
+ current_attr_call = None
+ }
+ None if ast::Attr::can_cast(node.kind()) => inside_attribute = false,
+ _ => (),
+ },
  _ => (),
  }
 
  let element = match event {
  WalkEvent::Enter(it) => it,
- WalkEvent::Leave(it) => {
- if let Some(node) = it.as_node() {
- inject::doc_comment(hl, sema, root.with_value(node));
- }
+ WalkEvent::Leave(NodeOrToken::Token(_)) => continue,
+ WalkEvent::Leave(NodeOrToken::Node(node)) => {
+ inject::doc_comment(hl, sema, root.with_value(&node));
  continue;
  }
  };
 
- let range = element.text_range();
-
  if current_macro.is_some() {
  if let Some(tok) = element.as_token() {
  macro_highlighter.advance(tok);
  }
  }
 
- let descend_token = (current_macro_call.is_some() || current_attr_call.is_some())
- && element.kind() != COMMENT;
+ // only attempt to descend if we are inside a macro call or attribute
+ // as calling `descend_into_macros_single` gets rather expensive if done for every single token
+ let descend_token = current_macro_call.is_some() || current_attr_call.is_some();
  let element_to_highlight = if descend_token {
- // Inside a macro -- expand it first
- let token = match element.clone().into_token() {
- Some(it) if current_macro_call.is_some() => {
- let not_in_tt = it.parent().map_or(true, |it| it.kind() != TOKEN_TREE);
- if not_in_tt {
- continue;
- }
- it
- }
- Some(it) => it,
- _ => continue,
+ let token = match &element {
+ NodeOrToken::Node(_) => continue,
+ NodeOrToken::Token(tok) => tok.clone(),
+ };
+ let in_mcall_outside_tt = current_macro_call.is_some()
+ && token.parent().as_ref().map(SyntaxNode::kind) != Some(TOKEN_TREE);
+ let token = match in_mcall_outside_tt {
+ // not in the macros token tree, don't attempt to descend
+ true => token,
+ false => sema.descend_into_macros_single(token),
  };
- let token = sema.descend_into_macros_single(token);
  match token.parent() {
  Some(parent) => {
- // We only care Name and Name_ref
+ // Names and NameRefs have special semantics, use them instead of the tokens
+ // as otherwise we won't ever visit them
  match (token.kind(), parent.kind()) {
  (T![ident], NAME | NAME_REF) => parent.into(),
  (T![self] | T![super] | T![crate], NAME_REF) => parent.into(),
@@ -323,10 +311,14 @@ fn traverse(
  element.clone()
  };
 
- if macro_highlighter.highlight(element_to_highlight.clone()).is_some() {
+ // FIXME: do proper macro def highlighting https://github.com/rust-analyzer/rust-analyzer/issues/6232
+ // Skip metavariables from being highlighted to prevent keyword highlighting in them
+ if macro_highlighter.highlight(&element_to_highlight).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(token_to_highlight)) =
  (element.into_token(), element_to_highlight.as_token())
  {
@@ -354,13 +346,15 @@ fn traverse(
  }
  }
 
- if let Some((mut highlight, binding_hash)) = highlight::element(
+ // do the normal highlighting
+ let element = highlight::element(
  sema,
  krate,
  &mut bindings_shadow_count,
  syntactic_name_ref_highlighting,
- element_to_highlight.clone(),
- ) {
+ element_to_highlight,
+ );
+ if let Some((mut highlight, binding_hash)) = element {
  if inside_attribute {
  highlight |= HlMod::Attribute
  }
@@ -369,18 +363,3 @@ fn traverse(
  }
  }
 }
-
-fn macro_call_range(macro_call: &ast::MacroCall) -> Option<TextRange> {
- let path = macro_call.path()?;
- let name_ref = path.segment()?.name_ref()?;
-
- let range_start = name_ref.syntax().text_range().start();
- let mut range_end = name_ref.syntax().text_range().end();
- for sibling in path.syntax().siblings_with_tokens(Direction::Next) {
- if let T![!] | T![ident] = sibling.kind() {
- range_end = sibling.text_range().end();
- }
- }
-
- Some(TextRange::new(range_start, range_end))
-}

crates/ide/src/syntax_highlighting/highlight.rs

@@ -81,7 +81,7 @@ fn token(
  T![::] | T![->] | T![=>] | T![..] | T![=] | T![@] | T![.] => {
  HlOperator::Other.into()
  }
- T![!] if parent_matches::<ast::MacroCall>(&token) => SymbolKind::Macro.into(),
+ T![!] if parent_matches::<ast::MacroCall>(&token) => HlPunct::MacroBang.into(),
  T![!] if parent_matches::<ast::NeverType>(&token) => HlTag::BuiltinType.into(),
  T![!] if parent_matches::<ast::PrefixExpr>(&token) => HlOperator::Logical.into(),
  T![*] if parent_matches::<ast::PtrType>(&token) => HlTag::Keyword.into(),

crates/ide/src/syntax_highlighting/macro_.rs

@@ -19,7 +19,7 @@ impl MacroHighlighter {
  }
  }
 
- pub(super) fn highlight(&self, element: SyntaxElement) -> Option<HlRange> {
+ pub(super) fn highlight(&self, element: &SyntaxElement) -> Option<HlRange> {
  if let Some(state) = self.state.as_ref() {
  if matches!(state.rule_state, RuleState::Matcher | RuleState::Expander) {
  if let Some(range) = is_metavariable(element) {
@@ -115,7 +115,7 @@ fn update_macro_state(state: &mut MacroMatcherParseState, tok: &SyntaxToken) {
  }
 }
 
-fn is_metavariable(element: SyntaxElement) -> Option<TextRange> {
+fn is_metavariable(element: &SyntaxElement) -> Option<TextRange> {
  let tok = element.as_token()?;
  match tok.kind() {
  kind if kind == SyntaxKind::IDENT || kind.is_keyword() => {

crates/ide/src/syntax_highlighting/tags.rs

@@ -102,6 +102,8 @@ pub enum HlPunct {
  Colon,
  /// ;
  Semi,
+ /// ! (only for macro calls)
+ MacroBang,
  ///
  Other,
 }
@@ -167,6 +169,7 @@ impl HlTag {
  HlPunct::Dot => "dot",
  HlPunct::Colon => "colon",
  HlPunct::Semi => "semicolon",
+ HlPunct::MacroBang => "macro_bang",
  HlPunct::Other => "punctuation",
  },
  HlTag::NumericLiteral => "numeric_literal",