Monotonically increasing counter (was Re: [Contrib PATCH] Add scripts to convert GCC repo from SVN to Git)

[Jason Merrill <jason at redhat dot com>]

On Mon, Aug 5, 2019 at 9:20 AM Martin Liška <mliska@suse.cz> wrote:

> Based on the IRC discussion with Jakub, there's missing key element of the transition.
> Jakub requests to have a monotonically increasing revisions (aka rXXXXXXX) to be assigned
> for the future git revisions. These will be linked from bugzilla and http://gcc.gnu.org/rNNNNN
>
> I don't like the suggested requirement and I would prefer to use git hashes for both bugzilla
> links and general references to revisions. That's what all projects using git do.

I agree.  But for those who want a monotonically increasing
identifier, there's already one in git: CommitDate.  In the discussion
of this issue four years ago,

https://gcc.gnu.org/ml/gcc/2015-09/threads.html#00028

I provided a set of git aliases to generate and use reposurgeon-style
action stamps for naming commits.  For Jakub's use-case, the committer
part of the action stamp is probably unnecessary, just the date/time
part should be enough.

Looking at it again, I notice that the different timezones in the
committer date would interfere with sorting, so this update to the
stamp alias uses UTC unconditionally:

stamp = "!f(){ TZ=UTC git show -s
--date='format-local:%Y-%m-%dT%H:%M:%SZ' --format='%cd!%ce'
${1:+\"$@\"}; }; f"

To drop the committer from the stamp, remove "!%ce" from the format argument.

Jakub, it seems to me that this should do the trick for you; binaries
would be named by date/time rather than by revision.  What do you
think?

Jason