Re: Automatic (e)tags generation and incremental updates

[Dmitry Gutov <dgutov@yandex.ru>]

Hi Eli,

On 07.01.2021 17:56, Dmitry Gutov wrote:
> - A change to lib-src/etags.c which implements handing of '-L' flag, for 
> compatibility with ctags.

How do you feel about cherry-picking this particular change to the 
emacs-27 release branch?

If we do that, we could later offer etags-regen as "ELPA core" to Emacs 
27.2 users, to get additional testing and feedback, instead of having it 
incubate in master for another year or so until the next release.

Or if you don't, how do you feel about that code change at all? One 
alternative for me is to try to support both 'ctags -e' and 'etags', 
with some ad-hoc version detection, I guess. Then the change won't be 
needed.

Code-wise, it is only this (though it might need doc changes):

diff --git a/lib-src/etags.c b/lib-src/etags.c
index b5c18e0e01..d79c6f4783 100644
--- a/lib-src/etags.c
+++ b/lib-src/etags.c
@@ -1112,7 +1112,7 @@ main (int argc, char **argv)
    /* When the optstring begins with a '-' getopt_long does not 
rearrange the
       non-options arguments to be at the end, but leaves them alone. */
    optstring = concat ("-ac:Cf:Il:o:Qr:RSVhH",
-                     (CTAGS) ? "BxdtTuvw" : "Di:",
+                     (CTAGS) ? "BxdtTuvw" : "Di:L:",
                       "");

    while ((opt = getopt_long (argc, argv, optstring, longopts, NULL)) 
!= EOF)
@@ -1124,6 +1124,7 @@ main (int argc, char **argv)
         break;

        case 1:
+      case 'L':
         /* This means that a file name has been seen.  Record it. */
         argbuffer[current_arg].arg_type = at_filename;
         argbuffer[current_arg].what     = optarg;