[gn] Add swarming support

[gn] Add swarming support

BUG=chromium:474921
Committed: https://crrev.com/928dd32993fc9afd321d806f9cd7261fe9073d89
Cr-Commit-Position: refs/heads/master@{#36694}

[Michael Achenbach, 2016-06-02 14:18:27]

Description was changed from

==========
[gn] Add swarming support

BUG=
==========

to

==========
[gn] Add swarming support

BUG=chromium:474921
==========

[Michael Achenbach, 2016-06-02 14:23:56]

machenbach@chromium.org changed reviewers:
+ jochen@chromium.org, vogelheim@chromium.org

[Michael Achenbach, 2016-06-02 14:23:57]

PTAL. This is an alternative route instead of using the swarming feature in mb
(of which we don't know yet if it'll work for v8, lots of chromium'ish
assumptions in there). Or instead of using mb at all (which also doesn't work
for v8, yet).

https://codereview.chromium.org/2034633004/diff/1/BUILD.gn
File BUILD.gn (right):

https://codereview.chromium.org/2034633004/diff/1/BUILD.gn#newcode2144
BUILD.gn:2144: v8_isolate_run("d8") {
This ports https://cs.chromium.org/chromium/src/v8/src/d8.gyp?l=142

Only d8 for now to test this on the staging bot. Others in follow up CLs.

https://codereview.chromium.org/2034633004/diff/1/gni/isolate.gni
File gni/isolate.gni (right):

https://codereview.chromium.org/2034633004/diff/1/gni/isolate.gni#newcode4
gni/isolate.gni:4: 
This ports https://cs.chromium.org/chromium/src/v8/gypfiles/isolate.gypi?l=40

https://codereview.chromium.org/2034633004/diff/1/gni/isolate.gni#newcode17
gni/isolate.gni:17: if (name != "" && invoker.isolate != "" && invoker.deps !=
[] &&
Referencing a bunch of variables here for the sake of using the
v8_test_isolation_mode != "noop" condition here. If it's noop, the variables
would be unused and gn would error out.

https://codereview.chromium.org/2034633004/diff/1/gni/isolate.gni#newcode38
gni/isolate.gni:38: # Translate gn to gyp variables.
The following 40 lines are probably a bit ugly. But there's no function
mechanism in gn to ease the 1/0 thing a bit.

The underlying isolate files expect gyp jargon, which can be changed, once gyp
gets deprecated.

[Michael Achenbach, 2016-06-02 14:24:26]

The CQ bit was checked by machenbach@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-06-02 14:24:36]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2034633004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2034633004/1

[commit-bot: I haz the power, 2016-06-02 14:57:07]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-06-02 14:57:08]

Dry run: This issue passed the CQ dry run.

[vogelheim, 2016-06-02 16:18:06]

Generally looks good, but I really don't get the part in isolate.gni... :(

https://codereview.chromium.org/2034633004/diff/1/gni/isolate.gni
File gni/isolate.gni (right):

https://codereview.chromium.org/2034633004/diff/1/gni/isolate.gni#newcode17
gni/isolate.gni:17: if (name != "" && invoker.isolate != "" && invoker.deps !=
[] &&
On 2016/06/02 14:23:57, Michael Achenbach wrote:
> Referencing a bunch of variables here for the sake of using the
> v8_test_isolation_mode != "noop" condition here. If it's noop, the variables
> would be unused and gn would error out.

Sorry, I don't get this... could you explain once more?

[Michael Achenbach, 2016-06-02 18:32:35]

https://codereview.chromium.org/2034633004/diff/1/gni/isolate.gni
File gni/isolate.gni (right):

https://codereview.chromium.org/2034633004/diff/1/gni/isolate.gni#newcode17
gni/isolate.gni:17: if (name != "" && invoker.isolate != "" && invoker.deps !=
[] &&
On 2016/06/02 16:18:05, vogelheim wrote:
> On 2016/06/02 14:23:57, Michael Achenbach wrote:
> > Referencing a bunch of variables here for the sake of using the
> > v8_test_isolation_mode != "noop" condition here. If it's noop, the variables
> > would be unused and gn would error out.
> 
> Sorry, I don't get this... could you explain once more?

I'd like to have the condition v8_test_isolation_mode != "noop" once here and
not around the definitions of the many different v8_isolate_run actions to come.
In gyp, that condition is repeated everywhere, but here we can be smarter.

If I do that and the condition is not met, i.e. v8_test_isolation_mode ==
"noop", the code below won't be executed (which is correct). But gn is smart and
realizes that all the variables defined in the template (i.e. target_name,
isolate, deps) are not used. GN treats that as an error and fails.

So I have two choices: Either move the v8_test_isolation_mode == "noop" around
e.g. v8_isolate_run("d8") and all other similar targets, or pseudo-use the
variables by checking them all against a value they shouldn't and won't ever
have (which is not a bad sanity check after all).

[vogelheim, 2016-06-03 08:14:20]

lgtm

Thanks for the explanation.

[Michael Achenbach, 2016-06-03 08:15:28]

The CQ bit was checked by machenbach@chromium.org

[commit-bot: I haz the power, 2016-06-03 08:15:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2034633004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2034633004/1

[commit-bot: I haz the power, 2016-06-03 08:16:57]

Description was changed from

==========
[gn] Add swarming support

BUG=chromium:474921
==========

to

==========
[gn] Add swarming support

BUG=chromium:474921
==========

[commit-bot: I haz the power, 2016-06-03 08:16:58]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-06-03 08:18:05]

Description was changed from

==========
[gn] Add swarming support

BUG=chromium:474921
==========

to

==========
[gn] Add swarming support

BUG=chromium:474921

Committed: https://crrev.com/928dd32993fc9afd321d806f9cd7261fe9073d89
Cr-Commit-Position: refs/heads/master@{#36694}
==========

[commit-bot: I haz the power, 2016-06-03 08:18:06]

Patchset 1 (id:??) landed as
https://crrev.com/928dd32993fc9afd321d806f9cd7261fe9073d89
Cr-Commit-Position: refs/heads/master@{#36694}