commit 2be26a709c303995d70ca0deb19e65e8483efa7a
author Nate Biggs <natebiggs@google.com> Fri Dec 29 07:13:09 2023 +0000
committer Commit Queue <dart-scoped@luci-project-accounts.iam.gserviceaccount.com> Fri Dec 29 07:13:09 2023 +0000
tree aac04ca5df11fe0dec5ed0e7f99288215ccfdcf8
parent 0c4147675f7d74437030a7838a3f1c1d156efcb7

[dart2js] Generate parameter stubs during codegen.

Today we make a half-hearted attempt to generate the correct default type arguments for parameter stubs. By the time we create them in the emitter we don't have enough information to fully replace all the type variables that might appear in a type parameter's bound. So instead we erase all type variables to "any".

By generating parameter stubs in SSA we can use existing RTI infrastructure to generate the correct recipes/bindings/evals. Instead of directly creating JS we create the appropriate SSA graph and let the normal function compiler do the heavy lifting.

There are benefits and drawbacks to this new approach:
1) The stub bodies go through the SSA optimizer so some parameters are abbreviated, some recurring nulls get replaced by a variable, etc. The net result is slightly more compact code.
2) We are now compiling code during the emitter phase. This is relatively fast (adds ~2% duration to the phase) but also requires deserializing some data we weren't previously using. This results in ~200MB more memory being used. I've changed the serialization layout a bit to try to mitigate this but some of it is unavoidable.

Change-Id: Ie786da933accc039716e1c8481dbb8a09f3cc9b2
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/340700
Reviewed-by: Stephen Adams <sra@google.com>
Reviewed-by: Kallen Tu <kallentu@google.com>
Commit-Queue: Nate Biggs <natebiggs@google.com>