We recently added the ability to pass a `--write-dump-info-data=` flag to Dart2JS's emitter phase which will serialize the necessary metadata to run dump info as a standalone phase of the compiler.
This extra metadata was incurring an overhead since we were maintaining JS AST nodes longer in order to extract metadata out of them. With this change we get rid of that overhead. The nodes are only retained until they printed and then any references to them are freed.
After this change the memory usage of the emitter phase is the same with or without the `--write-dump-info-data=` flag. There is still however some additional overhead in runtime. This is of course unavoidable as we are doing extra work to serialize the data.
Change-Id: Ib45a0e1de96d41503cbd76217b841ff013ac0655
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/331000
Reviewed-by: Sigmund Cherem <sigmund@google.com>
Commit-Queue: Nate Biggs <natebiggs@google.com>
Nate Biggs
849459109a