Re: Generation of tags for the current project on the fly

[Eli Zaretskii]

> Cc: address@hidden
> From: Dmitry Gutov <address@hidden>
> Date: Wed, 17 Jan 2018 22:43:17 +0300
> 
> On 1/17/18 18:40, Eli Zaretskii wrote:
> 
> >> The information is inside the TAGS file, isn't it?
> > 
> > Not really: the signature of each file at the moment of scan is
> > missing, and maybe also other things.
> 
> Meaning it's not known at etags runtime? That's true.

It's also not recorded after the run, so that the next run could
compare against it.

> Make tracks which files need to be recompiled, right? This could reuse 
> the same mechanism, if possible.

Make doesn't support incremental builds, except on file granularity.
Doing that with etags would be easy, but you say that is not the
"incremental" tagging you had in mind, you want the granularity to be
below file, i.e. on tag level.  For that, a single time stamp of the
TAGS file is insufficient, because all it can tell you is which files
need to be re-tagged, whereas you want to know that on a per-tag
basis.