commit d150ad8a812137f0cffe8ed30ce6d22958dff7e3
author Martin Kustermann <kustermann@google.com> Thu Jun 13 13:10:50 2024 +0000
committer Commit Queue <dart-scoped@luci-project-accounts.iam.gserviceaccount.com> Thu Jun 13 13:10:50 2024 +0000
tree 372e2e2c7f807237af67054b20fc330aa740a03e
parent d289a725a3a9a0aa427716b414c3105aafca3617

[dart2wasm] Move local constant variable to top-level

The flutter platform file is compiled slightly differently from the way
we compile the normal SDK platform file. This slight difference -
somehow related to how -D environments are used in CFE - results in a
constant `VariableDeclaration` to stay in the kernel in flutter's case
but not in the Dart SDK's case.

(All usages of constant variables / fields will be
`ConstantExpression(<const>)` instead of
`VariableGet(<constant-variable>)`)

That in itself causes the kernel verifier AST visitor (which we call
from `pkg/dart2wasm/lib/compile.dart` in assertion mode enabled) to
report an error.

=> To work around this issue we hoist the only variable affected by this
to top-level.

=> That will allow us to run the dart2wasm compiler in assertions mode
on flutter apps without hitting the verifier problem.

(This has very likely to do with the fact that in flutter's case the
variable must result in an `UnevaluatedConstant` which then at a later
stage gets evaluated whereas in Dart's case we do that eagerly).

There's no easy way to write a test for this, as normal test files will
have an environment and therefore don't result in unevaluated constants
afaik.

Change-Id: I883b91bdc37ede8b45e35a15d0dddc296d9da9ba
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/371340
Reviewed-by: Ömer Ağacan <omersa@google.com>
Commit-Queue: Martin Kustermann <kustermann@google.com>