Android: Expose more toolchain and NDK information to clients
Expose additional information to clients in Android builds:
CMAKE_ANDROID_NDK_TOOLCHAIN_VERSION: Set this to the default-selected toolchain version when it is not set by the user.
CMAKE_ANDROID_NDK_TOOLCHAIN_HOST_TAG: The NDK prebuilt toolchain host directory name (e.g.
CMAKE_<LANG>_ANDROID_TOOLCHAIN_MACHINE: The toolchain target machine (
These values are not needed for compiling within CMake but can be useful to clients that need to pass them to external tools.
For reference, this is inspired by discussion on the mailing list:
- Nov 2016: Android variables