Subject: Re: bug#73484: 31.0.50; Abolishing etags-regen-file-extensions

From: Eli Zaretskii <[email-masked]>
Date: Sat, 05 Oct 2024 20:12:25 +0300

> From: Francesco Potortì <[email-masked]>
> Date: Sat, 05 Oct 2024 18:38:22 +0200
> Cc: [email-masked],
> 	[email-masked],
> 	Eli Zaretskii <[email-masked]>
> 
> Eli Zaretskii:
> >> How hard is it to add to a live TAGS file fake lines which look like
> >> this:
> >> 
> >>    ^L
> >>    foo,0
> >> 
> >> (with random strings instead of "foo"), and then time some TAGS-using
> >> commands with and without these additions?
> 
> Dmitry Gutov:
> >Okay, done that.
> >
> >'M-.' takes more or less the same.
> >
> >The file size of TAGS increased from 66 MB to 85 MiB.
> >
> >Won't measure time to generate now - because the current method and the 
> >"real" one will be different, but note that it's more relevant with 
> >etags-regen-mode because the scan is performed lazily: every time the 
> >user does the first search in a new project.
> 
> Removing the Fortran and C/C++ fallbacks just for testing requires recompiling etags.c after removing the code beginning with /* Else try Fortran or C. */.  This would avoid parsing the file (except for detecting the sharp-bang) and would leave the file name in the tags file, without tags.

We are not talking about disabling the fallbacks, we are talking about
something else: the impact of having in TAGS names of files where no
tags were found (e.g., because their language was not recognized and
the fallbacks are disabled).