Add support for binding 'this'

Add support for binding 'this'

BUG=
R=dmitryas@google.com

Committed: https://github.com/dart-lang/sdk/commit/d62ff42f0efc06389b3b161bb871d5f2a58deef4

[zhivkag, 2017-07-13 11:11:52]

zhivkag@google.com changed reviewers:
+ dmitryas@google.com, kmillikin@google.com

[Dmitry Stefantsov, 2017-07-14 00:43:08]

I have a couple of questions.  Please, find them below.

https://codereview.chromium.org/2978893002/diff/1/pkg/kernel/lib/interpreter/...
File pkg/kernel/lib/interpreter/interpreter.dart (right):

https://codereview.chromium.org/2978893002/diff/1/pkg/kernel/lib/interpreter/...
pkg/kernel/lib/interpreter/interpreter.dart:73: for (Binding b in
bindings.reversed) {
Is it important that [bindings] is reversed?

https://codereview.chromium.org/2978893002/diff/1/pkg/kernel/lib/interpreter/...
pkg/kernel/lib/interpreter/interpreter.dart:88: assert(containsThis());
If we pass this `assert`, then at some iteration of the following loop we'll
return some location, and `parent.lookupThis()` will never be executed.

[zhivkag, 2017-07-14 07:02:32]

https://codereview.chromium.org/2978893002/diff/1/pkg/kernel/lib/interpreter/...
File pkg/kernel/lib/interpreter/interpreter.dart (right):

https://codereview.chromium.org/2978893002/diff/1/pkg/kernel/lib/interpreter/...
pkg/kernel/lib/interpreter/interpreter.dart:73: for (Binding b in
bindings.reversed) {
On 2017/07/14 00:43:08, Dmitry Stefantsov wrote:
> Is it important that [bindings] is reversed?

Done.

https://codereview.chromium.org/2978893002/diff/1/pkg/kernel/lib/interpreter/...
pkg/kernel/lib/interpreter/interpreter.dart:88: assert(containsThis());
On 2017/07/14 00:43:07, Dmitry Stefantsov wrote:
> If we pass this `assert`, then at some iteration of the following loop we'll
> return some location, and `parent.lookupThis()` will never be executed.

The intent of this assert is similar to "contains" for normal variables
declarations: check if `this` is bound in the current environment or any of its
parents.
When the assert passes, a location will eventually be returned, but not
necessarily from the loop below, it could also be with `parent.lookupThis()`.

[Dmitry Stefantsov, 2017-07-18 10:45:15]

LGTM

https://codereview.chromium.org/2978893002/diff/1/pkg/kernel/lib/interpreter/...
File pkg/kernel/lib/interpreter/interpreter.dart (right):

https://codereview.chromium.org/2978893002/diff/1/pkg/kernel/lib/interpreter/...
pkg/kernel/lib/interpreter/interpreter.dart:88: assert(containsThis());
On 2017/07/14 07:02:31, zhivkag wrote:
> On 2017/07/14 00:43:07, Dmitry Stefantsov wrote:
> > If we pass this `assert`, then at some iteration of the following loop we'll
> > return some location, and `parent.lookupThis()` will never be executed.
> 
> The intent of this assert is similar to "contains" for normal variables
> declarations: check if `this` is bound in the current environment or any of
its
> parents.
> When the assert passes, a location will eventually be returned, but not
> necessarily from the loop below, it could also be with `parent.lookupThis()`.

Yep.  I misinterpreted [containsThis] above.  Thanks for the clarification!

[zhivkag, 2017-07-18 11:19:05]

Description was changed from

==========
Add support for binding 'this'

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

to

==========
Add support for binding 'this'

BUG=
R=dmitryas@google.com

Committed:
https://github.com/dart-lang/sdk/commit/d62ff42f0efc06389b3b161bb871d5f2a58deef4
==========

[zhivkag, 2017-07-18 11:19:06]

Committed patchset #2 (id:20001) manually as
d62ff42f0efc06389b3b161bb871d5f2a58deef4 (presubmit successful).