commit 600fccb9bbf7442fd4ca2caa4414d67269950ead
author Paul Berry <paulberry@google.com> Thu Apr 20 23:30:21 2023 +0000
committer Commit Queue <dart-scoped@luci-project-accounts.iam.gserviceaccount.com> Thu Apr 20 23:30:21 2023 +0000
tree 54f4df88caedc4cd2739703efadc6f3d66b253ef
parent df9c6eb48fb6e601f6aada7db0b1398f086ec541

Rework exhaustiveness witness generation to allow analyzer to capture import info.

In order for an analyzer quick fix to aid the user in correcting
exhaustiveness errors, it needs to know not just the text of the
witness pattern that needs to be inserted, but also which elements are
referenced by the identifiers in that pattern.  This will allow it to
add in imports if the user's code doesn't yet import the necessary
library, or insert import prefixes in the case where the user is
already importing the necessary library in a prefixed fashion.

To reduce the effect on the exhaustiveness logic (which was designed
with the intention of building up the witness pattern into a
StringBuffer), we introduce a new type, `DartTemplateBuffer`, which
behaves similarly to StringBuffer but also captures the necessary
semantic information so that the analyzer will be able to fix up
imports in an appropriate way.

This change is mostly isolated to the _fe_analyzer_shared package; it
doesn't add the necessary logic to the analyzer to capture the
elements; it simply plumbs them up to the API boundary between the
packages.  Future CLs will add the necessary analyzer logic to make
use of the information.

Change-Id: I7c030fc49a2510acbefd6aeb567e0e7b7102855a
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/296385
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Commit-Queue: Paul Berry <paulberry@google.com>
Reviewed-by: Nate Bosch <nbosch@google.com>