commit f180b7037c0d1a566e4cdae0d408dc3dc47729b1
author Paul Berry <paulberry@google.com> Sun Jun 04 19:40:37 2023 +0000
committer Commit Queue <dart-scoped@luci-project-accounts.iam.gserviceaccount.com> Sun Jun 04 19:40:37 2023 +0000
tree d1671e45867f899b9e3def97ca91df60dd9074cf
parent 5e5fe2aa773a25697fa70e39fc57d305289174a0

Shared analysis: remove bogus support for late variable patterns.

When I was first developing the shared analysis logic for patterns, I
imagined that ordinary variable declaration statements would
eventually be re-interpreted as pattern variable declarations, where
the pattern was simply a variable pattern. In order to facilitate
this, I added support for late variable patterns, so that a
decalration of a late variable could be interpreted as a pattern
variable declaration where the pattern was a "late variable pattern".

In the final implementation, however, this functionality never got
used, except in flow analysis unit tests. Both the analyzer and the
CFE continue to use their old logic for analyzing ordinary variable
declarations (including late variable declarations), and only invoke
the shared logic when the declaration in question is truly a pattern
variable declaration.

In retrospect I believe this is the right approach; ordinary
(non-patterned) variable declarations are common enough that it makes
sense to have separate logic for analyzing theem; invoking the full
generality of pattern variable declarations would simply waste CPU
cycles.

So this CL removes support for late variable patterns from the shared
implementation; this will make future refactoring of flow analysis
logic easier.

Since the flow analysis unit tests *were* taking advantage of the
shared logic for late variable patterns, I had to add some separate
logic to the tests to replicate the old functionality when analyzing
an ordinary late variable declaration. This new logic is only used in
tests.

Change-Id: If51efab3c63bdc20d1f2772c2d2dd1e3f487bb00
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/307183
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Commit-Queue: Paul Berry <paulberry@google.com>