serial lines (was: Thoughts about ax_resip.m4, anyone?)

[Peter Simons]

Hi Peter,

 > Please encourage contributors to include a serial number in the .m4
 > file.

you are right. The Autotools take advantage of serial numbers, so our macros
should probably have them.

However, the fact is that right now no macro in the archive has a serial
number. We have discussed this subject before [1], and back then the
consensus seemed to be that the way to go is to generate serial numbers
automatically from the Git repository. We could, for instance, count the
number of commits that have modified a macro. The file, say ax_pthread.m4,
would be marked "# serial 2", because of:

  $ git log m4/ax_pthread.m4 | egrep -c "^commit [0-9a-f]+"
  2

The open question that has kept us from implementing this feature so far is:
how do we ensure (automatically) that serial numbers are always up-to-date
in every file?

Take care,
Peter


[1] 
http://lists.gnu.org/archive/html/autoconf-archive-maintainers/2009-07/msg00000.html