Removing the export tier traversal will require us to change how some PGO-related export rules are performed. We currently run pgo_merge.py and pgomgr during export (https://mxr.mozilla.org/mozilla-central/source/js/src/config/rules.mk#799). It looks like we should be able to look for directories that contain PROGRAM or SHARED_LIBRARY and perform actions in each of them in one go instead of recursing into make files.

We could definitely do this all in one go at the beginning of the MOZ_PROFILE_USE=1 pass of the build.

This is a largely mechanical change. Just making pgomerge.py consistent with "modern" build actions. I haven't tested this. Wouldn't be surprised if I did something stupid. Expect some more invasive changes to this file in subsequent parts. While I was here, I switched to 4 space indent and added argparse because consistent and modern style is good.

Comment on attachment 805765 [details] [diff] [review] Part 1: Move pgomerge.py into a build action Review of attachment 805765 [details] [diff] [review]: ----------------------------------------------------------------- argparse seems a little overkill here, but it's not a big deal.

I'm not actively working on this. But we /should/ have enough data in moz.build to move this rule out of rules.mk.