bug#22306: 24.5; Unhide --no-line-directive Documentation

[James Muchow <jim_muchow@dell.com>]

> From: Francesco Potortì [mailto:pot@gnu.org] 
> Sent: Saturday, January 09, 2016 5:27 PM
>>> From: James Muchow <jim_muchow@dell.com>
>>> Date: Mon, 4 Jan 2016 19:41:28 +0000
>>> 
>>> In trying to create a TAGS file, etags would process the
>>> #line directive in various source files and produce TAGS 
>>> files that were unusable because the "file name" included
>>> would be unavailable causing the tags-search to exit before
>>> having seen all files.
>>> 
>>> I spent a lot of time coming up with a solution to avoid
>>> any files that contained a line directive when the solution
>>> I really needed was already present: --no-line-directive.
>>> It is, however, undocumented and thus the only way to know
>>> about it is to download the source. I downloaded the source
>>> to try and find out what etags was doing wrong with #line
>>> when I discovered this undocumented option.
>>> 
>>> I see from the source that the --no-line-directive is hidden
>>> by the PRINT_UNDOCUMENTED_OPTIONS_HELP; I think it would be
>>> helpful for others to remove this restriction.
>>
>> Francesco,
>> 
>> Are there any reasons to keep this option (and a few others) hidden
>> from the user eyes?
>
> For this specific otion, the logs say that I undocumented it in 2002.
> As far as I can recall, this was because the option seemed too much
> technical to me, that is of little use and difficult to explain.  I
> think I adopted the same criterion for undocumenting the other options.

First of all thanks for cleaning up my request and getting rid of
all the extraneous verbiage. I've never filed a bug report before,
so I didn't quite know what to expect. Anyway...

I am aware that the documentation hiding was done years ago. As to
whether it is too technical or not; the fact is that in our
environment, the TAGS files I produced are useless (30M of 
useless) and that was quickly diagnosed to those files that use 
the #line directive.

Resolving this issue involved, as I wrote, a lot of time when the
solution was already present the whole time. A solution of which
I was unaware because it was deemed too technical.

I now know of this option, so I could take the "I don't care, I
got mine" approach, but I thought that such a trivial fix might
be turn out to be helpful to someone else. But YMMV, I'll leave
the eventual resolution in your hands.