commit 08c60454c1f3de61c474ee1663d9cd6dcd751c5d
author Paul Berry <paulberry@google.com> Thu Apr 28 17:14:30 2022 +0000
committer Commit Bot <commit-bot@chromium.org> Thu Apr 28 17:14:30 2022 +0000
tree 54957e62e59066d11924978f36ee1a4bd33914a9
parent edb7fb4b1e1efd76ef3a99d1c2395cf8b6621cc5

Defer analysis of closure arguments when `inference-update-1` is enabled.

In order to address https://github.com/dart-lang/language/issues/731
(improved type inference for `fold` etc.) we're going to need to
sometimes defer analysis of invocation arguments that are closures, so
that closure parameters can have their types inferred based on other
parameters.  To avoid annoying the user with inconsistent behaviors,
we defer analysis of closures in all circumstances, even if it's not
necessary to do so for type inference purposes.

This has a minor user-visible effect: if an invocation contains some
closures and some non-closures, any demotions that happen due to write
captures in the closures are postponed until the end of the
invocation; this means that the write-captured variables remain
promoted for other invocation arguments, even if those arguments
appear after the closure.  This is safe because there is no way for
the closure to be called until after all of the other invocation
arguments are evaluated.  See the language tests in
tests/language/inference_update_1/write_capture_deferral_enabled_test.dart
for details.

Note that this change only has an effect when the experimental feature
`inference-update-1` is enabled.

Change-Id: If7bb38e361755180c033ecb2108fc4fffa7570b1
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/241864
Reviewed-by: Chloe Stefantsova <cstefantsova@google.com>
Commit-Queue: Paul Berry <paulberry@google.com>