Alexander Markov
742850f9cc
Previously, TFA was building a summary for the comparison
'v == null' assuming type of 'v' is Null on the true branch.
As a result, after joining data flow Null contaminates value of 'v'
further down:
v0 = ...
t1 = IsNull(v0) // Condition
t2 = Null // On true branch
t3 = NarrowNotNull(v0) // On false branch
v1 = Join(t2, t3) // This value is nullable even if v0 was not.
...
use(v1)
This change adds a condition to the Null value so it is evaluated to
Empty type if original value turns out to be non-nullable:
t1 = IsNull(v0)
t2 = Move(Null) {t1} // Empty if t1 is false.
t3 = NarrowNotNull(v0)
v1 = Join(t2, t3)
TEST=pkg/vm/testcases/transformations/type_flow/transformer/regress_59845.dart
Fixes https://github.com/dart-lang/sdk/issues/59845
Change-Id: I0f78e31f9eaf6507cc78e393de2fc12a9cf29f4a
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/403200
Reviewed-by: Slava Egorov <vegorov@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Package validation
The packages in pkg/ are automatically validated on the LUCI CI bots. The
validation is largely done by the tools/package_deps package; it can be tested
locally via:
dart tools/package_deps/bin/package_deps.dart
Packages which are published
There are several packages developed in pkg/ which are published to pub.
Validation of these packages is particularly important because the pub tools are
not used for these packages during development; we get our dependency versions
from the DEPS file. It's very easy for the dependencies specified in a package's
pubspec file to get out of date wrt the packages and versions actually used.
In order to better ensure we're publishing correct packages, we validate some properties of the pubspec files on our CI system. These validations include:
- that the dependencies listed in the pubspec are used in the package
- that all the packages used by the source are listed in the pubspec
- that we don't use relative path deps to pkg/ or third_party/ packages
Packages which are not published
For packages in pkg/ which we do not intend to be published, we put the following comment in the pubspec.yaml file:
# This package is not intended for consumption on pub.dev. DO NOT publish.
publish_to: none
These pubspecs are still validated by the package validation tool. The contents are more informational as the pubspecs for these packages are not consumed by the pub tool or ecosystem.
We validate:
- that the dependencies listed in the pubspec are used in the package
- that all the packages used by the source are listed in the pubspec
- that a reference to a pkg/ package is done via a relative path dependency