minor: drop dead code

Author: matklad

crates/hir_expand/src/db.rs

@@ -215,6 +215,8 @@ fn parse_or_expand(db: &dyn AstDatabase, file_id: HirFileId) -> Option<SyntaxNod
  match file_id.0 {
  HirFileIdRepr::FileId(file_id) => Some(db.parse(file_id).tree().syntax().clone()),
  HirFileIdRepr::MacroFile(macro_file) => {
+ // FIXME: Note how we convert from `Parse` to `SyntaxNode` here,
+ // forgetting about parse errors.
  db.parse_macro_expansion(macro_file).value.map(|(it, _)| it.syntax_node())
  }
  }

crates/mbe/src/syntax_bridge.rs

@@ -1,7 +1,7 @@
 //! Conversions between [`SyntaxNode`] and [`tt::TokenTree`].
 
 use rustc_hash::{FxHashMap, FxHashSet};
-use stdx::{never, non_empty_vec::NonEmptyVec};
+use stdx::non_empty_vec::NonEmptyVec;
 use syntax::{
  ast::{self, make::tokens::doc_comment},
  AstToken, Parse, PreorderWithTokens, SmolStr, SyntaxElement, SyntaxKind,
@@ -66,10 +66,6 @@ pub fn token_tree_to_syntax_node(
  parser::Step::Error { msg } => tree_sink.error(msg.to_string()),
  }
  }
- if never!(tree_sink.roots.len() != 1) {
- return Err(ExpandError::ConversionError);
- }
- //FIXME: would be cool to report errors
  let (parse, range_map) = tree_sink.finish();
  Ok((parse, range_map))
 }
@@ -614,10 +610,6 @@ struct TtTreeSink<'a> {
  text_pos: TextSize,
  inner: SyntaxTreeBuilder,
  token_map: TokenMap,
-
- // Number of roots
- // Use for detect ill-form tree which is not single root
- roots: smallvec::SmallVec<[usize; 1]>,
 }
 
 impl<'a> TtTreeSink<'a> {
@@ -628,7 +620,6 @@ impl<'a> TtTreeSink<'a> {
  open_delims: FxHashMap::default(),
  text_pos: 0.into(),
  inner: SyntaxTreeBuilder::default(),
- roots: smallvec::SmallVec::new(),
  token_map: TokenMap::default(),
  }
  }
@@ -733,16 +724,10 @@ impl<'a> TtTreeSink<'a> {
 
  fn start_node(&mut self, kind: SyntaxKind) {
  self.inner.start_node(kind);
-
- match self.roots.last_mut() {
- None | Some(0) => self.roots.push(1),
- Some(n) => *n += 1,
- };
  }
 
  fn finish_node(&mut self) {
  self.inner.finish_node();
- *self.roots.last_mut().unwrap() -= 1;
  }
 
  fn error(&mut self, error: String) {