remove some unused vars

src/libsyntax/ext/tt/quoted.rs

@@ -11,13 +11,13 @@
 use ast::NodeId;
 use early_buffered_lints::BufferedEarlyLintId;
 use ext::tt::macro_parser;
-use feature_gate::{self, emit_feature_err, Features, GateIssue};
+use feature_gate::Features;
 use parse::{token, ParseSess};
 use print::pprust;
 use symbol::keywords;
 use syntax_pos::{edition::Edition, BytePos, Span};
 use tokenstream::{self, DelimSpan};
-use {ast, attr};
+use ast;
 
 use rustc_data_structures::sync::Lrc;
 use std::iter::Peekable;
@@ -566,16 +566,16 @@ fn parse_sep_and_kleene_op_2018<I>(
     input: &mut Peekable<I>,
     span: Span,
     sess: &ParseSess,
-    features: &Features,
-    attrs: &[ast::Attribute],
+    _features: &Features,
+    _attrs: &[ast::Attribute],
 ) -> (Option<token::Token>, KleeneOp)
 where
     I: Iterator<Item = tokenstream::TokenTree>,
 {
     // We basically look at two token trees here, denoted as #1 and #2 below
     let span = match parse_kleene_op(input, span) {
         // #1 is a `?` (needs feature gate)
-        Ok(Ok((op, op1_span))) if op == KleeneOp::ZeroOrOne => {
+        Ok(Ok((op, _op1_span))) if op == KleeneOp::ZeroOrOne => {
             return (None, op);
         }
 
@@ -585,7 +585,7 @@ where
         // #1 is a separator followed by #2, a KleeneOp
         Ok(Err((tok, span))) => match parse_kleene_op(input, span) {
             // #2 is the `?` Kleene op, which does not take a separator (error)
-            Ok(Ok((op, op2_span))) if op == KleeneOp::ZeroOrOne => {
+            Ok(Ok((op, _op2_span))) if op == KleeneOp::ZeroOrOne => {
                 // Error!
                 sess.span_diagnostic.span_err(
                     span,