Fix result type checking of factory constructors of generic classes in VM.

Fix result type checking of factory constructors of generic classes in VM.
Add a language test.
Fix some language tests.
Fix runtime library.
Note: This does not yet fix result checking of redirecting factories.
Committed: https://code.google.com/p/dart/source/detail?r=14769

[hausner, 2012-11-09 23:43:44]

lgtm

[ngeoffray, 2012-11-10 22:15:45]

Regis, are you aware that this change caused a big regression on running dart2js
in checked mode? For example, a dart2js unit test
(tests/compiler/dart2js/field_type_inferer_test) went from 13 seconds to 58
seconds (sometimes reaching 1 minute and therefore triggering a timeout on the
buildbot).

[regis, 2012-11-11 21:51:23]

On 2012/11/10 22:15:45, ngeoffray wrote:
> Regis, are you aware that this change caused a big regression on running
dart2js
> in checked mode? For example, a dart2js unit test
> (tests/compiler/dart2js/field_type_inferer_test) went from 13 seconds to 58
> seconds (sometimes reaching 1 minute and therefore triggering a timeout on the
> buildbot).

Nicolas,
I was not aware of the impact of this change on dart2js in checked mode. With
all the language changes done to factories over the last months, a type check
got crippled by mistake at some time. The issue arises with a factory declared
in a generic class M<T>. The result returned by the factory must be checked to
be of type M<T>. Prior to this cl, the result was only checked to be M<dynamic>.

The bad news is that redirecting factories are still missing a type check, so it
will get slower before getting faster.

I am not sure if this is something Srdjan and his team can optimize. I'll
discuss with him this week.

Thanks for the heads up.
Regis

[ahe, 2012-11-12 06:43:37]

I have filed bug 6658 to track this.  This is a big problem for dart2js, as it
cripples checked mode for us.

See the build bot:
http://build.chromium.org/p/client.dart.fyi/builders/dart2js-linux-release-ho...

Cheers,
Peter

On 2012/11/11 21:51:23, regis wrote:
> On 2012/11/10 22:15:45, ngeoffray wrote:
> > Regis, are you aware that this change caused a big regression on running
> dart2js
> > in checked mode? For example, a dart2js unit test
> > (tests/compiler/dart2js/field_type_inferer_test) went from 13 seconds to 58
> > seconds (sometimes reaching 1 minute and therefore triggering a timeout on
the
> > buildbot).
> 
> Nicolas,
> I was not aware of the impact of this change on dart2js in checked mode. With
> all the language changes done to factories over the last months, a type check
> got crippled by mistake at some time. The issue arises with a factory declared
> in a generic class M<T>. The result returned by the factory must be checked to
> be of type M<T>. Prior to this cl, the result was only checked to be
M<dynamic>.
> 
> The bad news is that redirecting factories are still missing a type check, so
it
> will get slower before getting faster.
> 
> I am not sure if this is something Srdjan and his team can optimize. I'll
> discuss with him this week.
> 
> Thanks for the heads up.
> Regis