Reland "Track the 'awaiter return' call stack..."

Reland "Track the 'awaiter return' call stack..."

Original CL: https://codereview.chromium.org/2692803006/

Original commit message:
Tracking the awaiter return call stack:

- [x] Each async function closure now knows who is awaiting on their
return. This is effectively the asynchronous equivalent of the 'frame pointer'.
- [x] Each async* function closure now knows how is listening on their
stream. This is effectively the asynchronous equivalent of the 'frame pointer'.

Detecting uncaught exceptions in async functions:

- [x] Code object keeps a map from :await_jump_var to token position
- [x] Exception Handlers keep track if they are generated (as part of compilation) or directly from user code
- [x] Debugger maps :await_jump_var to a specific try index

R=johnmccutchan@google.com

Committed: https://github.com/dart-lang/sdk/commit/f31b6d5e2c370b7254fede0cb13a8d4311ba035e

[Kevin Millikin (Google), 2017-02-28 15:07:20]

kmillikin@google.com changed reviewers:
+ johnmccutchan@google.com, kustermann@google.com, vegorov@google.com

[Kevin Millikin (Google), 2017-02-28 15:07:21]

This includes support for `await` by calling _awaitHelper in dart:async with the
correct arguments.  It does not include support for `await for` which does not
appear to be run on the Kernel buildbots (unless I'm missing something).

[Cutch, 2017-02-28 15:08:31]

LGTM and thanks!

[Kevin Millikin (Google), 2017-02-28 15:13:47]

Description was changed from

==========
Reland "Track the 'awaiter return' call stack..."

Original CL: https://codereview.chromium.org/2692803006/

Original commit message:
Tracking the awaiter return call stack:

- [x] Each async function closure now knows who is awaiting on their
return. This is effectively the asynchronous equivalent of the 'frame pointer'.
- [x] Each async* function closure now knows how is listening on their
stream. This is effectively the asynchronous equivalent of the 'frame pointer'.

Detecting uncaught exceptions in async functions:

- [x] Code object keeps a map from :await_jump_var to token position
- [x] Exception Handlers keep track if they are generated (as part of
compilation) or directly from user code
- [x] Debugger maps :await_jump_var to a specific try index
==========

to

==========
Reland "Track the 'awaiter return' call stack..."

Original CL: https://codereview.chromium.org/2692803006/

Original commit message:
Tracking the awaiter return call stack:

- [x] Each async function closure now knows who is awaiting on their
return. This is effectively the asynchronous equivalent of the 'frame pointer'.
- [x] Each async* function closure now knows how is listening on their
stream. This is effectively the asynchronous equivalent of the 'frame pointer'.

Detecting uncaught exceptions in async functions:

- [x] Code object keeps a map from :await_jump_var to token position
- [x] Exception Handlers keep track if they are generated (as part of
compilation) or directly from user code
- [x] Debugger maps :await_jump_var to a specific try index

R=johnmccutchan@google.com

Committed:
https://github.com/dart-lang/sdk/commit/f31b6d5e2c370b7254fede0cb13a8d4311ba035e
==========

[Kevin Millikin (Google), 2017-02-28 15:13:48]

Committed patchset #2 (id:20001) manually as
f31b6d5e2c370b7254fede0cb13a8d4311ba035e (presubmit successful).

[kustermann, 2017-02-28 15:29:50]

Kevin's change: LGTM

@John: How does 'await for' work with non _Stream's? As opposed to Future's, we
actually do have different implementations of Stream, like Socket IIRC?

https://codereview.chromium.org/2725623003/diff/20001/runtime/lib/async_patch...
File runtime/lib/async_patch.dart (right):

https://codereview.chromium.org/2725623003/diff/20001/runtime/lib/async_patch...
runtime/lib/async_patch.dart:51: var awaiter) {
var -> Function

https://codereview.chromium.org/2725623003/diff/20001/runtime/lib/async_patch...
runtime/lib/async_patch.dart:71: void _asyncStarListenHelper(var object, var
awaiter) {
var -> Future

[Cutch, 2017-02-28 15:35:28]

On 2017/02/28 15:29:50, kustermann wrote:
> Kevin's change: LGTM
> 
> @John: How does 'await for' work with non _Stream's? As opposed to Future's,
we
> actually do have different implementations of Stream, like Socket IIRC?
> 

Currently, these features only work for async* functions and await for loops. We
could probably patch the private field onto a base class or mixin and have it
work for more Stream implementations?