Beautify syntax error for unterminated argument list

src/preparser.h

Index: src/preparser.h
diff --git a/src/preparser.h b/src/preparser.h
index a17296349b362df6afefbb5b8538d7c030915270..a580a47d8639ecd92fc53f42b2115c5b78dd8468 100644
--- a/src/preparser.h
+++ b/src/preparser.h
@@ -2319,8 +2319,13 @@ typename Traits::Type::ExpressionList ParserBase<Traits>::ParseArguments(
     }
     done = (peek() == Token::RPAREN);

[Yang, 2015/03/16 07:24:33]

I think it's cleaner and easier to read if we check for Token::COMMA here to see
whether to continue looping, and...

[yurys, 2015/03/16 08:56:23]

Done.

     if (!done) {
-      // Need {} because of the CHECK_OK_CUSTOM macro.
-      Expect(Token::COMMA, CHECK_OK_CUSTOM(NullExpressionList));
+      Scanner::Location location = scanner_->location();
+      Token::Value next = Next();
+      if (Token::COMMA != next) {
+        ReportMessageAt(location, "unterminated_arg_list");
+        *ok = false;
+        return this->NullExpressionList();
+      }
     }
   }
   Expect(Token::RPAREN, CHECK_OK_CUSTOM(NullExpressionList));

[Yang, 2015/03/16 07:24:33]

... check for Token::LPAREN here, throwing unterminated_arg_list if it's not.

That way the error message corresponds to the expectation.

[yurys, 2015/03/16 08:56:23]

Done.