Ignore unused classes when constructing set for deferred loading.

Ignore unused classes when constructing set for deferred loading.

BUG=dartbug.com/11740
R=ahe@google.com

Committed: https://code.google.com/p/dart/source/detail?r=25959

[aam-me, 2013-08-04 02:02:39]

Hi Peter,

  dartbug.com/11740 is caused by cls.allSupertypes for unused top-level class
TemplateBenchmark being null.
  I added simple check if (cls.thisType != null) to check whether cls class is
actually being used and therefore have to be included into deferred set.

  Please let me know what you think.

Thanks!

[ahe, 2013-08-06 16:00:34]

Nice detective work!

https://chromiumcodereview.appspot.com/22067002/diff/1/sdk/lib/_internal/comp...
File sdk/lib/_internal/compiler/implementation/deferred_load.dart (right):

https://chromiumcodereview.appspot.com/22067002/diff/1/sdk/lib/_internal/comp...
sdk/lib/_internal/compiler/implementation/deferred_load.dart:157: if
(cls.thisType != null) {
I think this check belongs on line 92, and it feels like it should be a little
more general. Something like a method in Enqueuer:

bool isLive(Element element) {
  if (seenClasses.contains(element)) return true;
  if (getCachedElements(element) != null) return true;
  return false;
}

[aam-me, 2013-08-07 03:20:42]

Thanks, Peter!

PTAL

https://chromiumcodereview.appspot.com/22067002/diff/1/sdk/lib/_internal/comp...
File sdk/lib/_internal/compiler/implementation/deferred_load.dart (right):

https://chromiumcodereview.appspot.com/22067002/diff/1/sdk/lib/_internal/comp...
sdk/lib/_internal/compiler/implementation/deferred_load.dart:157: if
(cls.thisType != null) {
Thanks, makes sense.
Done.

[aam-me, 2013-08-08 03:29:25]

Hello Peter,

  I apologize - I think my original Patch 2 got corrupted somehow as I could not
see my changes in this review, you could not I'm sure neither.
  So I just resubmitted it for your review. Please take a look when you have a
chance.

[ahe, 2013-08-08 11:36:51]

https://chromiumcodereview.appspot.com/22067002/diff/23001/sdk/lib/_internal/...
File sdk/lib/_internal/compiler/implementation/deferred_load.dart (right):

https://chromiumcodereview.appspot.com/22067002/diff/23001/sdk/lib/_internal/...
sdk/lib/_internal/compiler/implementation/deferred_load.dart:159: if
(cls.thisType != null) {
Can you revert this part of the change now?

[aam-me, 2013-08-08 11:54:15]

Oh, gosh. Thanks!

PTAL.

[ahe, 2013-08-08 12:02:25]

LGTM, thank you!

[aam-me, 2013-08-09 01:56:21]

Committed patchset #3 manually as r25959 (presubmit successful).