platform_build/Deprecation.md
Dan Willemsen efee0692d4 Obsolete unused module types
These were deprecated in R, which has now branched, and there aren't any
users on master.

Test: build-aosp_crosshatch.ninja is identical
Test: treehugger
Change-Id: I6286880e45c0facbae56f9a16e8cfcbde12f121c
2020-04-18 21:00:18 -07:00

3.4 KiB

Deprecation of Make

We've made significant progress converting AOSP from Make to Soong (Android.mk to Android.bp), and we're ready to start turning off pieces of Make. If you have any problems converting, please contact us via:

Status

build/make/core/deprecation.mk is the source of truth, but for easy browsing:

Module type State
BUILD_AUX_EXECUTABLE Obsolete
BUILD_AUX_STATIC_LIBRARY Obsolete
BUILD_COPY_HEADERS Error
BUILD_HOST_EXECUTABLE Error
BUILD_HOST_FUZZ_TEST Obsolete
BUILD_HOST_NATIVE_TEST Obsolete
BUILD_HOST_SHARED_LIBRARY Error
BUILD_HOST_SHARED_TEST_LIBRARY Obsolete
BUILD_HOST_STATIC_LIBRARY Error
BUILD_HOST_STATIC_TEST_LIBRARY Obsolete
BUILD_HOST_TEST_CONFIG Obsolete
BUILD_NATIVE_BENCHMARK Obsolete
BUILD_SHARED_TEST_LIBRARY Obsolete
BUILD_STATIC_TEST_LIBRARY Obsolete
BUILD_TARGET_TEST_CONFIG Obsolete
BUILD_* Available

Module Type Deprecation Process

We'll be turning off BUILD_* module types as all of the users are removed from AOSP (and Google's internal trees). The process will go something like this, using BUILD_PACKAGE as an example:

  • Prerequisite: all common users of BUILD_PACKAGE have been removed (some device-specific ones may remain).
  • BUILD_PACKAGE will be moved from AVAILABLE_BUILD_MODULE_TYPES to DEFAULT_WARNING_BUILD_MODULE_TYPES in build/make/core/deprecation.mk. This will make referring to BUILD_PACKAGE a warning.
  • Any devices that still have warnings will have BUILD_BROKEN_USES_BUILD_PACKAGE := true added to their BoardConfig.mk.
  • BUILD_PACKAGE will be switched from DEFAULT_WARNING_BUILD_MODULE_TYPES to DEFAULT_ERROR_BUILD_MODULE_TYPES, which will turn referring to BUILD_PACKAGE into an error unless the device has overridden it.
  • At some later point, after all devices in AOSP no longer set BUILD_BROKEN_USES_BUILD_PACKAGE, BUILD_PACKAGE will be moved from DEFAULT_ERROR_BUILD_MODULE_TYPES to OBSOLETE_BUILD_MODULE_TYPES and the code will be removed. It will no longer be possible to use BUILD_PACKAGE.

In most cases, we expect module types to stay in the default warning state for about two weeks before becoming an error by default. Then it will spend some amount of time in the default error state before moving to obsolete -- we'll try and keep that around for a while, but other development may cause those to break, and the fix may to be to obsolete them. There is no expectation that the BUILD_BROKEN_USES_BUILD_* workarounds will work in a future release, it's a short-term workaround.

Just to be clear, the above process will happen on the AOSP master branch. So if you're following Android releases, none of the deprecation steps will be in Android Q, and the 2020 release will have jumped directly to the end for many module types.