Support for AwaitExpression in unlinked expressions.

Support for AwaitExpression in unlinked expressions.

This code was failing when analyzing dev_compiler with the new driver.
var instanceVarArrowExpression = (f) async => await f;

The reason was that we:
1. Don't understand AwaitExpression in AbstractConstExprSerializer.
2. So, we throw StateError.
3. So, AbstractConstExprSerializer.serialize() marks isValidConst.
4. But we don't check 'isValidConst' in linker.
5. The list of operations is empty, so we don't have anything in stack.
6. So, we throw an exception in linker.


R=paulberry@google.com
BUG=

Committed: https://github.com/dart-lang/sdk/commit/38635ec91e933a21b5438ee0f2eed7b43991d49f

[Paul Berry, 2016-11-29 19:15:58]

https://codereview.chromium.org/2541603002/diff/1/pkg/analyzer/lib/src/summar...
File pkg/analyzer/lib/src/summary/idl.dart (right):

https://codereview.chromium.org/2541603002/diff/1/pkg/analyzer/lib/src/summar...
pkg/analyzer/lib/src/summary/idl.dart:2347: * into the stack.  Otherwise, push
`dynamic`.
This comment should reflect the behavior of values, not types.  So it should say
something like:

"Pop the top value from the stack.  Treat it as a Future and await its
completion.  Then push the awaited value onto the stack."

https://codereview.chromium.org/2541603002/diff/1/pkg/analyzer/lib/src/summar...
File pkg/analyzer/lib/src/summary/link.dart (right):

https://codereview.chromium.org/2541603002/diff/1/pkg/analyzer/lib/src/summar...
pkg/analyzer/lib/src/summary/link.dart:2374: stack.add(typeArgument);
Do we need to flatten futures here?  The spec says that the static type of an
await expression is flattened.

[scheglov, 2016-11-29 19:39:13]

PTAL

https://codereview.chromium.org/2541603002/diff/1/pkg/analyzer/lib/src/summar...
File pkg/analyzer/lib/src/summary/idl.dart (right):

https://codereview.chromium.org/2541603002/diff/1/pkg/analyzer/lib/src/summar...
pkg/analyzer/lib/src/summary/idl.dart:2347: * into the stack.  Otherwise, push
`dynamic`.
On 2016/11/29 19:15:57, Paul Berry wrote:
> This comment should reflect the behavior of values, not types.  So it should
say
> something like:
> 
> "Pop the top value from the stack.  Treat it as a Future and await its
> completion.  Then push the awaited value onto the stack."

Done.

https://codereview.chromium.org/2541603002/diff/1/pkg/analyzer/lib/src/summar...
File pkg/analyzer/lib/src/summary/link.dart (right):

https://codereview.chromium.org/2541603002/diff/1/pkg/analyzer/lib/src/summar...
pkg/analyzer/lib/src/summary/link.dart:2374: stack.add(typeArgument);
On 2016/11/29 19:15:57, Paul Berry wrote:
> Do we need to flatten futures here?  The spec says that the static type of an
> await expression is flattened.

Done.

[Paul Berry, 2016-11-29 20:13:20]

lgtm

[scheglov, 2016-11-29 21:22:37]

Description was changed from

==========
Support for AwaitExpression in unlinked expressions.

This code was failing when analyzing dev_compiler with the new driver.
var instanceVarArrowExpression = (f) async => await f;

The reason was that we:
1. Don't understand AwaitExpression in AbstractConstExprSerializer.
2. So, we throw StateError.
3. So, AbstractConstExprSerializer.serialize() marks isValidConst.
4. But we don't check 'isValidConst' in linker.
5. The list of operations is empty, so we don't have anything in stack.
6. So, we throw an exception in linker.


R=paulberry@google.com
BUG=
==========

to

==========
Support for AwaitExpression in unlinked expressions.

This code was failing when analyzing dev_compiler with the new driver.
var instanceVarArrowExpression = (f) async => await f;

The reason was that we:
1. Don't understand AwaitExpression in AbstractConstExprSerializer.
2. So, we throw StateError.
3. So, AbstractConstExprSerializer.serialize() marks isValidConst.
4. But we don't check 'isValidConst' in linker.
5. The list of operations is empty, so we don't have anything in stack.
6. So, we throw an exception in linker.


R=paulberry@google.com
BUG=

Committed:
https://github.com/dart-lang/sdk/commit/38635ec91e933a21b5438ee0f2eed7b43991d49f
==========

[scheglov, 2016-11-29 21:22:41]

Committed patchset #2 (id:20001) manually as
38635ec91e933a21b5438ee0f2eed7b43991d49f (presubmit successful).