Experimental Physics and
Industrial Control System

Michael Davidsaver via Core-talk <core-talk at aps.anl.gov> · Tue, 30 Jun 2020 09:07:17 -0700

I clicked send too soon.  More below.

On 6/30/20 7:26 AM, Zimoch Dirk (PSI) via Core-talk wrote:
> Hi folks,
> 
> I have a technical git related question. For StreamDevice, I used to update a version header file manually, but I always
> forgot to update the numbers when tagging a release. How can I do this automatically? Git has hooks, but none for tag as
> it seems (which would be also too late to be included in the tagged commit).
> 
> The internet says: "No problem, simply generate the header (e.g. from 'git describe') when building your code." No
> problem indeed as long as I have the git repo. But those users that download zip files from github instead of cloning
> the repo complain now, as 'git describe' does not work for them, of course.
> 
> Is there a way to generate the version header (or any other file that contains the related tag) on github when pushing
> the release, so it is included when downloading a release zip file?

I don't have a great answer to this.  I'm not sure there is one.
The best I know of is the git substitutions mechanism.

eg. from README in Base

> $Format:%cD$
> $Format:%H$

https://github.com/epics-base/epics-base/blob/32ff3b2ed99bc27b9f5f876f2a9a48a29c40f2fe/README#L25-L26

and with substitution enabled

https://github.com/epics-base/epics-base/blob/32ff3b2ed99bc27b9f5f876f2a9a48a29c40f2fe/.gitattributes#L5

"git export" produces a README containing eg.

> Mon, 29 Jun 2020 21:20:05 -0700
> e4e541e55e5f22d45ac4dff787f3a22b30d43b09

The various format strings are described by 'man git-log'.

https://git-scm.com/docs/git-log

So you might in your Makefile have something like

GENVERSIONDEFAULT=$Format:%d$

Though I'm bound to say that I've not bother with this.
My strategy these days is to reduce the number of places
where I have to change a version number.  Preferably to one.

This is done in Base, and eg. by a module

https://github.com/mdavidsaver/pvxs/blob/master/configure/CONFIG_PVXS_VERSION

I actually combine the two of these approaches so that the
manually created version number is accessible to user modules
both as make variables, and C macros.  The VCS revision is also
captured, but only to be printed in various places.

https://github.com/mdavidsaver/pvxs/blob/651d7d18fbece66f158477761e58f7d5ca915933/src/Makefile#L37-L44

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System