bug#22241: 25.0.50; etags Ruby parser problems

[Eli Zaretskii]

> Cc: 22241@debbugs.gnu.org
> From: Dmitry Gutov <dgutov@yandex.ru>
> Date: Thu, 4 Feb 2016 02:21:53 +0300
> 
> One nitpick:
> 
> attr_WHATEVER :foo, bar
> 
> will generate the methods for 'foo', and whatever the value of bar is. 
> But bar is not very likely to have the value :bar, so we should only 
> generate the tags for 'foo'.
> 
> IOW, skip the arguments that are not Ruby Symbols (don't start with a 
> colon). The current implementation treats them the same.

Yes, because etags is not supposed to do sensible things with
syntactically incorrect programs.

I'm not sure I understand the rules, though: is the "no colon, don't
tag" rule valid for any symbol following the attr_WHATEVER, or is that
applicable only to the 2nd, 3rd, etc. symbols?  IOW, what, if
anything, should be tagged here:

  attr_reader foo