Use the app snapshot when testing with -cdartk.

Use the app snapshot when testing with -cdartk.

Fix snapshot features check to use the checked mode status of the current isolate, and peg the kernel isolate to production mode.

BUG=

[rmacnak, 2017-02-01 00:10:18]

rmacnak@google.com changed reviewers:
+ asiva@google.com, hausner@google.com, vegorov@google.com

[rmacnak, 2017-02-01 00:10:18]

Note this increases test time relative to batch mode, but means we test the
configuration we expect to ship.

test.py -mrelease -cdartk language

batch               06:18  (status quo)
isolate, source     39:16
isolate, snapshot   13:47  (this CL)

[hausner, 2017-02-01 01:03:49]

LGTM.

Is the kernel-isolate snapshot still built with the 'runtime' target?

[rmacnak, 2017-02-01 01:08:55]

On 2017/02/01 01:03:49, hausner wrote:
> LGTM.
> 
> Is the kernel-isolate snapshot still built with the 'runtime' target?

No, I need to update the bots to build 'runtime_kernel' first.

[kustermann, 2017-02-01 08:48:06]

kustermann@google.com changed reviewers:
+ kustermann@google.com

[kustermann, 2017-02-01 08:48:07]

https://codereview.chromium.org/2669543003/diff/20001/tools/testing/dart/comp...
File tools/testing/dart/compiler_configuration.dart (right):

https://codereview.chromium.org/2669543003/diff/20001/tools/testing/dart/comp...
tools/testing/dart/compiler_configuration.dart:226:
args.add('--dfe=$buildDir/gen/kernel-service.dart.snapshot');
You should do the same in tools/testing/dart/test_runner.dart:


class BatchDFEProcess  {
  ...

  Future _startProcess() async {
    final executable = io.Platform.executable;
    final arguments = ['utils/kernel-service/kernel-service.dart', '--batch'];
    ...
  }
  ...
}

[Vyacheslav Egorov (Google), 2017-02-01 08:51:22]

https://codereview.chromium.org/2669543003/diff/20001/tools/testing/dart/comp...
File tools/testing/dart/compiler_configuration.dart (right):

https://codereview.chromium.org/2669543003/diff/20001/tools/testing/dart/comp...
tools/testing/dart/compiler_configuration.dart:226:
args.add('--dfe=$buildDir/gen/kernel-service.dart.snapshot');
On 2017/02/01 08:48:06, kustermann wrote:
> You should do the same in tools/testing/dart/test_runner.dart:
> 
> 
> class BatchDFEProcess  {
>   ...
> 
>   Future _startProcess() async {
>     final executable = io.Platform.executable;
>     final arguments = ['utils/kernel-service/kernel-service.dart', '--batch'];
>     ...
>   }
>   ...
> }

That would not work because snapshot versions are not necessarily compatible.

[kustermann, 2017-02-01 08:56:15]

https://codereview.chromium.org/2669543003/diff/20001/tools/testing/dart/comp...
File tools/testing/dart/compiler_configuration.dart (right):

https://codereview.chromium.org/2669543003/diff/20001/tools/testing/dart/comp...
tools/testing/dart/compiler_configuration.dart:226:
args.add('--dfe=$buildDir/gen/kernel-service.dart.snapshot');
On 2017/02/01 08:51:22, Vyacheslav Egorov (Google) wrote:
> On 2017/02/01 08:48:06, kustermann wrote:
> > You should do the same in tools/testing/dart/test_runner.dart:
> > 
> > 
> > class BatchDFEProcess  {
> >   ...
> > 
> >   Future _startProcess() async {
> >     final executable = io.Platform.executable;
> >     final arguments = ['utils/kernel-service/kernel-service.dart',
'--batch'];
> >     ...
> >   }
> >   ...
> > }
> 
> That would not work because snapshot versions are not necessarily compatible.

Good point.

If it was part of a normal dart sdk, we could have it next to the other
snapshots for our checked-in sdk, though:

$ ls tools/sdks/linux/dart-sdk/bin/snapshots 
analysis_server.dart.snapshot  dartanalyzer.dart.snapshot  dartdoc.dart.snapshot
 pub.dart.snapshot
utils_wrapper.dart.snapshot dart2js.dart.snapshot         
dartdevc.dart.snapshot      dartfmt.dart.snapshot

[Vyacheslav Egorov (Google), 2017-02-01 11:27:22]

Thanks for doing this Ryan! 

I am looking forward to using this.

Here is a comparison for the configuration that which we are testing all the
time: 

$ tools/test.py -a x64 -c dartk -r vm -m {debug, release} co19 language kernel

# Kernel isolate with batch mode workers.
[16:11 | 100% | +12685 | -    2] RELEASE
[57:45 | 100% | +12682 | -    5] DEBUG      

# Kernel isolate with APPJIT, no batch mode workers
[37:50 | 100% | +12675 | -   12] RELEASE
[92:42 | 100% | +12607 | -   80] DEBUG

Two things to notice here:

- cycle time is increased by 20 and 30 minutes respectively. I don't think this
is good; 

- there are additional failures in both debug and release - these need to be
investigated before this can become a default mode;

I have the following suggestion:

- We keep default -c dartk configuration as a batch mode runner. This saves
noticable amount of time for those of us who work on correctness of Kernel
compilation and Kernel-to-IL transformation.

- We add flag to turn on app-jit mode on the bots and add bots that run "-c dart
--use-app-jit" configuration in the meanwhile.

- We need to figure out how to make build times reasonable: DEBUG and simulator
builds really suffer from the training time. Maybe we should file a bug for this
as well?