browserworks/waterfox-android/gn-check-autofix

GN Check Autofix

This skill provides instructions for using tools_webrtc/gn_check_autofix.py to automatically resolve common GN build configuration errors in WebRTC.

Core Workflows

Fix Missing Dependencies

When you see "Include not allowed" errors from gn gen --check, use this workflow:

1. Run the autofix tool on your output directory:

``bash tools_webrtc/gn_check_autofix.py -C <dir> ``

1. The tool will:

• Identify targets missing dependencies.
• Add the missing deps to the appropriate BUILD.gn files.
• Automatically run gn format on modified files.

Fix rtc_source_set Violations

If you see "rtc_source_set shall not contain cc files", the tool will automatically convert them to rtc_library:

1. Run the tool:

``bash tools_webrtc/gn_check_autofix.py -C <dir> ``

Clean Up Dependencies

To remove all non-absolute dependencies (those not starting with //) from specific BUILD.gn files:

tools_webrtc/gn_check_autofix.py -r path/to/BUILD.gn

Note: This preserves absolute dependencies (starting with `//`) and targets ending in `_test`, `_tests`, `_unittest`, or `_unittests`.

Integration with Include Cleaner

This tool is the recommended second step after running webrtc-include-cleaner. While the include cleaner updates your C++ source files, gn-check-autofix synchronizes your BUILD.gn files to match.

Parameters

• -C <dir>: Path to a local build directory (e.g., out/Default). The tool

internally runs gn gen --check --error-limit=20000.

• -r <files>: Remove all non-absolute dependencies from the specified files.
• --error-limit: Can be used to override the default error cap.

Post-Fix Steps

After the tool runs, always verify the changes:

1. Deduplicate: The tool may occasionally add a dependency that is already

present. Check the deps list for duplicates.

1. Regenerate GN: Run gn gen <dir> to confirm errors are resolved.
2. Format: The tool runs gn format, but a final git cl format is

recommended for consistency.

1. Review: Check the diff to ensure dependencies were added to the correct

targets.