Add a new flag to mb.py to allow duplicated isolate map entry

During the starlark migration for internal builders, the internal
gn_isolate_map.pyl will contain entries from public one, and lead to
duplicate entries when mb.py processes the files.

Add this flag to temporarily allow dup entries during migration.

Bug: 433525189
Change-Id: If81f019126857e7f1eedf46f2a35744d7e5f21b3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7146925
Reviewed-by: Garrett Beaty <[email protected]>
Commit-Queue: Haiyang Pan <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1545257}
NOKEYCHECK=True
GitOrigin-RevId: 6a479f65d886b169b439627a2b3599d24d886c6c
2 files changed
tree: 5d8511104b1cf9f9e91a9e18e463a02229a5e3cf
  1. docs/
  2. lib/
  3. mb_config_expectations/
  4. __init__.py
  5. DIR_METADATA
  6. mb
  7. mb.bat
  8. mb.py
  9. mb_config.pyl
  10. mb_unittest.py
  11. mb_validation_unittest.py
  12. OWNERS
  13. PRESUBMIT.py
  14. README.md
  15. rts_banned_suites.json
README.md

MB - The Meta-Build wrapper

MB is a simple wrapper around the GN build tool.

It was originally written as part of the GYP->GN migration, in order to provide a uniform interface to either GYP or GN, such that users and bots can call one script and not need to worry about whether a given bot was meant to use GN or GYP.

It eventually grew additional functionality and is now still used even though everything is GN-only.

It supports two main functions:

  1. “gen” - the main gn gen invocation that generates the Ninja files needed for the build.

  2. “analyze” - the step that takes a list of modified files and a list of desired targets and reports which targets will need to be rebuilt.

We also use MB as a forcing function to collect all of the different build configurations that we actually support for Chromium builds into one place, in //tools/mb/mb_config.pyl.

For more information, see: