Subzero: Include commit count in revision string.

Subzero: Include commit count in revision string.

Instead of the version string being like this:
  Subzero_revision_efdf412032f7622a0663696896708d75b82e92f6
Make it more like this:
  Subzero_revision_1089_efdf412032f7622a0663696896708d75b82e92f6
I.e., provide both git hash and commit count.

That way, it's easier to compare revision strings and determine which one is newer.

BUG= none
R=eholk@chromium.org

Committed: https://gerrit.chromium.org/gerrit/gitweb?p=native_client/pnacl-subzero.git;a=commit;h=6b0ee2aba2ccc689d658b813504fafa8ca9726ab

[Jim Stichnoth, 2016-08-17 18:56:35]

Description was changed from

==========
Subzero: Include commit count in revision string.

BUG= none
==========

to

==========
Subzero: Include commit count in revision string.

Instead of the version string being like this:
  Subzero_revision_efdf412032f7622a0663696896708d75b82e92f6
Make it more like this:
  Subzero_revision_1089_efdf412032f7622a0663696896708d75b82e92f6

That way, it's easier to compare two revisions for newer verus older.

BUG= none
==========

[Jim Stichnoth, 2016-08-17 20:16:05]

Description was changed from

==========
Subzero: Include commit count in revision string.

Instead of the version string being like this:
  Subzero_revision_efdf412032f7622a0663696896708d75b82e92f6
Make it more like this:
  Subzero_revision_1089_efdf412032f7622a0663696896708d75b82e92f6

That way, it's easier to compare two revisions for newer verus older.

BUG= none
==========

to

==========
Subzero: Include commit count in revision string.

Instead of the version string being like this:
  Subzero_revision_efdf412032f7622a0663696896708d75b82e92f6
Make it more like this:
  Subzero_revision_1089_efdf412032f7622a0663696896708d75b82e92f6
I.e., provide both git hash and commit count.

That way, it's easier to compare revision strings and determine which one is
newer.

BUG= none
==========

[Jim Stichnoth, 2016-08-17 20:17:12]

stichnot@chromium.org changed reviewers:
+ eholk@chromium.org, jpp@chromium.org, kschimpf@google.com

[Eric Holk, 2016-08-17 22:48:29]

lgtm

How does the revision count work in the presence of branches? I'm guessing it's
monotonically increasing, but the revision count may not be unique. We probably
can't rely in general on smaller numbers referring to earlier versions.

I'm guessing we don't actually have branches often, if ever, and even if we do,
we still have the commit hashes which we can rely on as a unique identifier.

[Jim Stichnoth, 2016-08-17 22:56:48]

On 2016/08/17 22:48:29, Eric Holk wrote:
> lgtm
> 
> How does the revision count work in the presence of branches? I'm guessing
it's
> monotonically increasing, but the revision count may not be unique. We
probably
> can't rely in general on smaller numbers referring to earlier versions.
> 
> I'm guessing we don't actually have branches often, if ever, and even if we
do,
> we still have the commit hashes which we can rely on as a unique identifier.

I believe the revision count is the number of commits from the root to this
point, so it wouldn't make to compare these numbers across different branches.

I don't think it's a big deal in practice, because so far every Subzero release
(and probably every PNaCl release) has been from master.

I meant this just as a quick way for a user to look at their "strings <binary> |
grep Subzero_revision_" output (when directed by us) and be able to tell that
"obviously" their PNaCl isn't up to date.

At the end of the day, the git hash is the ground truth.

[Eric Holk, 2016-08-17 22:58:54]

Sounds good to me!

[Jim Stichnoth, 2016-08-17 23:20:25]

Description was changed from

==========
Subzero: Include commit count in revision string.

Instead of the version string being like this:
  Subzero_revision_efdf412032f7622a0663696896708d75b82e92f6
Make it more like this:
  Subzero_revision_1089_efdf412032f7622a0663696896708d75b82e92f6
I.e., provide both git hash and commit count.

That way, it's easier to compare revision strings and determine which one is
newer.

BUG= none
==========

to

==========
Subzero: Include commit count in revision string.

Instead of the version string being like this:
  Subzero_revision_efdf412032f7622a0663696896708d75b82e92f6
Make it more like this:
  Subzero_revision_1089_efdf412032f7622a0663696896708d75b82e92f6
I.e., provide both git hash and commit count.

That way, it's easier to compare revision strings and determine which one is
newer.

BUG= none
R=eholk@chromium.org

Committed:
https://gerrit.chromium.org/gerrit/gitweb?p=native_client/pnacl-subzero.git;a...
==========

[Jim Stichnoth, 2016-08-17 23:20:26]

Committed patchset #1 (id:1) manually as
6b0ee2aba2ccc689d658b813504fafa8ca9726ab (presubmit successful).