Ninja to Soong

ninja-to-soong is a project to generate Soong files (Android.bp) for the Android build system.

Legal

ninja-to-soong is licensed under the terms of the Apache 2.0 license

How does it work?

1. ninja-to-soong generates Ninja files using either:
   • CMake and the Android NDK
   • GN cross-compiling for Android
   • Meson and the Android NDK
2. ninja-to-soong generates Soong files using Ninja files.

Dependencies

• Rust
• Ninja
• CMake
• GN
• Meson
• Linux commands (wget, unzip, ...)

Using ninja-to-soong

<ninja-to-soong> $ cargo run --release -- --aosp-path <path> <project1> <project2>

Options

• --aosp-path <path>: Path to Android tree (required for most project)
• --clean-tmp: Remove the temporary directory before running
• --copy-to-aosp: Copy generated Soong files into the Android tree
• --skip-build: Skip build step
• --skip-gen-ninja: Skip generation of Ninja files
• -h, --help: Display the help and exit

Environment variables

• N2S_ANGLE_PATH: Path to angle sources (default: <aosp-path>/external/angle)
• N2S_MESA_PATH: Path to mesa sources (default: <aosp-path>/external/mesa)
• N2S_NDK: Android NDK (default: android-ndk-r27c)
• N2S_NDK_PATH: Path to Android NDK (default: temporary directory)
• N2S_TMP_PATH: Path used by ninja-to-soong to store its temporary directories (default: std::env::temp_dir())

Supported projects

Project	Ninja Generator	Targets
clvk	CMake	libclvk.so
clspv	CMake	clvk dependencies
llvm-project	CMake	clvk & clspv dependencies
SPIRV-Tools	CMake	clvk dependencies
SPIRV-Headers	CMake	clspv & SPIRV-Tools dependencies
angle (WIP)	GN	libEGL_angle.so, libGLESv2_angle.so, libGLESv1_CM_angle.so
mesa	meson	libEGL_mesa.so, libGLESv2_mesa.so, libGLESv1_CM_mesa.so, libvulkan.so

Adding a project

To add a project, create a <project>.rs implementing the Project trait under the project folder.

Then add the project in define_ProjectId! in project.rs.

The following feature can be used to output debug information when writting a new project:

<ninja-to-soong> $ cargo run --release --features debug_project -- --aosp-path <path> <new_project>

Tests

ninja-to-soong uses github actions to check that changes do not bring regression. It checks that the generated files match their reference (located in the tests folder).

Each project in the tests folder contains the following files:

• Android.bp: the reference file to generate
• checkout.sh: a script to checkout the repository in the CI
• gen-ninja.sh: a script to generate Ninja files

Modification to checkout.sh & gen-ninja.sh trigger the generation of Ninja files in the CI, otherwise it uses the cached files from a previous CI run.

If you want more information take a look at the github action script