update-native-rev - SKILL.md Agent Skill

name: update-native-rev description: Updates the native_rev dependency in the DEPS file with all correct verification, sync, and testing procedures

Instructions

Use this skill when you are requested to roll or update the native_rev variable (the hash of third_party/pkg/native repository) in the DEPS file.

1. Commit Selection Rules

[!IMPORTANT] CRITICAL RULE: NEVER EVER pick a local commit or a commit from a custom branch/PR branch. You MUST only pick remote commits that have already landed on the remote main branch.

To select the correct commit SHA:

Ask the user if the newest hash/commit should be taken directly from GitHub (e.g., if the googlesource mirror is lagging behind or the desired change is only on GitHub main).
- If the user says YES:
  1. First, temporarily change the repository URL and host permissions in the DEPS file by following the instructions in the Troubleshooting Sync Failures section (changing third_party/pkg/native under deps to use "https://github.com/dart-lang/native.git" and adding 'github.com' to allowed_hosts in DEPS).
  2. Run gclient sync from the SDK root to update the checkout mapping to GitHub.
  3. Navigate to the native package subdirectory: third_party/pkg/native.
  4. Run git fetch origin to fetch the latest commits from the GitHub remote (origin will now point to GitHub).
  5. After checking commits, immediately set the repository URL and host permissions in DEPS back to googlesource (reverting the changes made in sub-step 1), so that subsequent steps and the final commit only roll the commit hash without permanently keeping GitHub host settings.
- If the user says NO / default:
  1. Proceed with the default mirrored googlesource setup.
  2. Navigate to the native package subdirectory: third_party/pkg/native.
  3. Run git fetch origin to fetch the latest commits from the mirror.
Inspect the commits on remote origin/main of the native repository:
```
git log origin/main -n 10 --oneline
```
Obtain the full SHA of the newest commit on remote origin/main (or the specific one that contains the required change):
```
git rev-parse origin/main
```
Revert Host to GoogleSource:
- IMPORTANT: If the host was set to GitHub, you MUST now revert the repository URL and allowed hosts changes in the DEPS file back to the mirrored googlesource URL, removing github.com from allowed_hosts. Do this before updating native_rev so that the final committed change only rolls the commit hash, not checkout hosts.

2. Updating DEPS and Synchronizing

Locate native_rev in the DEPS file (typically under vars):

"native_rev": "<old_sha>", # rolled manually while record_use is experimental

Replace the hash with the chosen remote origin/main commit SHA.
If not already done in step 4 above, ensure the DEPS host and URL configuration are reverted to the googlesource mirror, leaving only the updated native_rev hash.
Run gclient sync -f from the SDK root directory to update the checkout of the dependencies and regenerate the package configuration using the mirror.

Troubleshooting Sync Failures

If the synchronization fails because of host restrictions:

Temporarily modify the repository configuration under deps in DEPS to use: https://github.com/dart-lang/native.git as the git repo.
Temporarily add 'github.com' to the allowed_hosts list in DEPS.
Re-run gclient sync -f to complete the update.
IMPORTANT: Immediately after successful syncing, revert the host and URL changes in the DEPS file, removing github.com from allowed_hosts and returning to the mirrored googlesource URL, but keep the newly synced native commit hash.

3. Mandatory Testing and Verification

Before completing the update, you must run the following tests:

Native Assets Package Tests

Build the target SDK and run the primary native asset tests:

tools/build.py -mrelease create_sdk runtime ffi_test_functions runtime_precompiled && tools/test.py -n unittest-asserts-release-mac-arm64 pkg/dartdev/test/native_assets/

Record Use Optimization Tests

Since record_use integrates closely with native_rev updates, these tests must be validated for both backends (Wasm and VM).

Build the required target backends and run all record use tests:

tools/build.py -mrelease create_sdk dart2wasm runtime ffi_test_functions runtime_precompiled && xcodebuild/ReleaseARM64/dart-sdk/bin/dart pkg/compiler/test/record_use/record_use_test.dart && xcodebuild/ReleaseARM64/dart-sdk/bin/dart pkg/dart2wasm/test/record_use_test.dart && xcodebuild/ReleaseARM64/dart-sdk/bin/dart pkg/vm/test/transformations/record_use_test.dart

Updating Expectations:

[!IMPORTANT] If the record_use tests fail, DO NOT update the expectations automatically. You MUST first ask the user for confirmation/permission and clarify if updating expectations is the correct course of action.

If the user confirms that the expectations should be updated to match the new behavior:
- Run the test command with -DupdateExpectations=true:
```
tools/build.py -mrelease create_sdk dart2wasm runtime ffi_test_functions runtime_precompiled && xcodebuild/ReleaseARM64/dart-sdk/bin/dart pkg/compiler/test/record_use/record_use_test.dart -DupdateExpectations=true && xcodebuild/ReleaseARM64/dart-sdk/bin/dart pkg/dart2wasm/test/record_use_test.dart -DupdateExpectations=true && xcodebuild/ReleaseARM64/dart-sdk/bin/dart pkg/vm/test/transformations/record_use_test.dart -DupdateExpectations=true
```
- Note: Always run the VM test one last when updating expectations. The expect files are stored in the VM directory.

Running Individual Tests: To debug or verify a single test:

python3 tools/test.py -n wasm-unittest-asserts-mac pkg/dart2wasm/test/record_use_test.dart

4. Pre-Completion Protocol

Follow these final validation steps before announcing completion:

Format touched files: Run dart format on all modified Dart files.
Analyze touched files: Run dart analyze to ensure there are no lint or static analysis issues.
Presubmit checks: Run git cl presubmit to ensure build/format sanity.
Update Coverage (Front-End changes only): If any related changes were also introduced in the front_end directory, regenerate test coverage:
```
dart --enable-asserts pkg/front_end/test/coverage_suite.dart --tasks=5 --add-and-remove-comments
```
- Critical: Revert the coverage comment changes in any files that you did not otherwise modify.