Split manifests are Android repo manifests that contain the minimum set of projects necessary to build a given target. If a project isn‘t used for building the target, it shouldn’t be in the split manifest. This smaller manifest can be used to sync the Android source tree and build the specific target. This sync should be faster and smaller than a sync of a full manifest because it is syncing less projects.
treble_manifest_split tool is used to automatically create a split manifest from a full manifest using dependency information from the source tree and the build outputs. The tool attempts to infer as many dependencies as it can, but some will be missed due to implicit dependencies in the build system and source tree. This is solved by manually fine-tuning a tool configuration XML specific to your target.
treble_manifest_split tool needs the ninja build graph and deps log from a completed build in order to have a full view of the dependency graph. While the build graph is created at the beginning of a ninja build, the deps log is not complete until the build finishes.
Use standard Android build commands to build your target.
# Change to the directory where you ran the full build. cd /path/to/android # Set command line variables for the Android target you are using and the build # target that should be buildable from your split manifest. ANDROID_TARGET=aosp_arm64-userdebug BUILD_TARGET=droid # Build treble_manifest_split as a python binary. lunch $ANDROID_TARGET m treble_manifest_split # Create the split manifest using a sample config XML specific to aosp_arm64. out/host/linux-x86/bin/treble_manifest_split \ --manifest .repo/manifests/default.xml \ --split-manifest split_default.xml \ --debug-file debug.json \ --config tools/treble/split/sample_config.xml \ $BUILD_TARGET
You should test that the split manifest created by the tool can be used to build the partial target files package.
.repo/manifests/default.xmlfull manifest with the newly-generated split manifest.
repo synccommands to sync your repo.
Build errors may arise due to missing dependencies that were previously provided by now-removed projects. These dependencies may be implicit in the source code, or an explicit dependency type that is not yet able to be automatically detected by the tool.
Find the dependency source project in your full-manifest repo directory.
Update your config XML to manually add projects to your split manifest.
sample_config.xmlin this tool directory specifies a project that should be included in the split manifest even if the tool doesn't automatically detect that it is necessary.
<add_project name="platform/external/python/cpython3" />
Regenerate the split manifest using
treble_manifest_split in your full-manifest directory. Remember to pass the path of your config XML to the script's
A successful build alone is not sufficient to have full confidence in the split manifest. You should diff the output artifacts of the split-manifest build against the output artifacts of the full-manifest build.
Suggestions for viewing diffs:
development/vndk/tools/image-diff-tool/diff.pyon output directories, or on a zipped target-files archive if you are creating
The following may cause differences between output artifacts: