Fix for 18468- T << Type where T is a type parameter and Type is the type Type from dart.core

Fix for 18468- T << Type where T is a type parameter and Type is the type Type from dart.core

R=brianwilkerson@google.com, scheglov@google.com

Committed: https://code.google.com/p/dart/source/detail?r=35501

[Brian Wilkerson, 2014-04-28 21:58:55]

LGTM

[scheglov, 2014-04-28 21:59:38]

LGTM

https://codereview.chromium.org/252693006/diff/1/editor/tools/plugins/com.goo...
File
editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/type/TypeParameterTypeImpl.java
(right):

https://codereview.chromium.org/252693006/diff/1/editor/tools/plugins/com.goo...
editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/type/TypeParameterTypeImpl.java:145:
LibraryElement libraryOfS = sElement != null ? sElement.getLibrary() : null;
sLibrary as sElement?
elementOfS as libraryOfS?

Just for consistency...

[jwren, 2014-04-28 22:09:30]

https://codereview.chromium.org/252693006/diff/1/editor/tools/plugins/com.goo...
File
editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/type/TypeParameterTypeImpl.java
(right):

https://codereview.chromium.org/252693006/diff/1/editor/tools/plugins/com.goo...
editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/type/TypeParameterTypeImpl.java:145:
LibraryElement libraryOfS = sElement != null ? sElement.getLibrary() : null;
On 2014/04/28 21:59:38, scheglov wrote:
> sLibrary as sElement?
> elementOfS as libraryOfS?
> 
> Just for consistency...

Done.

[jwren, 2014-04-28 22:10:21]

Committed patchset #2 manually as r35501 (presubmit successful).

[karlklose, 2014-04-30 09:42:40]

I think this is wrong: the issue of 18468 is that resolution does not correctly
identify the use of the type parameter as a value of type Type (see 12.31
Identifier reference).

Extending the more specific relation like this is incorrect, as the example
above demonstrates.

https://codereview.chromium.org/252693006/diff/10001/editor/tools/plugins/com...
File
editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/type/TypeParameterTypeImpl.java
(right):

https://codereview.chromium.org/252693006/diff/10001/editor/tools/plugins/com...
editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/type/TypeParameterTypeImpl.java:142:
// If s is of type Type from dart.core, return true
This is not correct: [Type] is a normal class and is not more specific than a
type variable.

This change makes Type assignable to any type variable, so this works,  too:
  class C<T> {
    foo() {
      T t = int;
    }
  }

[Nathan Collins, 2014-08-27 00:21:39]

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

[Nathan Collins, 2014-08-27 00:21:39]

See https://codereview.chromium.org/513563002 for a revert of the buggy
is-more-specific-than additions here and better fix for Issue 18468 by assigning
the static type [Type] to type parameters used as expressions.