commit 44f8e21c82899f51c3637594368e7c738d42244f
author Sigmund Cherem <sigmund@google.com> Tue Apr 01 08:49:11 2025 -0700
committer Commit Queue <dart-scoped@luci-project-accounts.iam.gserviceaccount.com> Tue Apr 01 08:49:11 2025 -0700
tree 6dfc7bd6b97101345b0919f0a97ec3db24c10a24
parent b46ee2cee8dd8abe77519e93b5ab3acaac7c9278

[kernel] Adds helper to trim dill files for modular dependencies.

Introduce a helper library to trim components based on what we believe
it is needed for modular bytecode compilation. The script is configured
to accept a set of entry points, so unreachable libraries can be removed
entirely. The contents of the retained libraries is trimmed to remove
method bodies, constructor bodies, and initializers, except for where
they may be needed.


In the near future, this should be expanded to:
* include proper unit testing in the CFE
* review whether additional trimming operations can be made
* consider an explicit representation of trimmed content, to help the
  CFE recover when assumptions are not met (e.g. sentinel markers
  to establish whether a value has been trimmed)
* CFE produces trimmed data directly if needed, without having to first
  produce the full dill.

Tests that specifically stress that we don't over-trim include:
apply_mixin (requires preserving method bodies), const_body (requires
preserving initializers).

TEST=existing and new e2e dynamic module aot tests.

b/394936876

Change-Id: I26db8385bdfe1664b2aea234ec8bb896c7c21230
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/418702
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Commit-Queue: Sigmund Cherem <sigmund@google.com>
Reviewed-by: Johnni Winther <johnniwinther@google.com>