Produce ro.build.version.preview_sdk_fingerprint

This is just a hash of the current.txt and system-current.txt right now,
though it may expand to include other API surfaces in the future.

Once prebuilts/sdk/current is populated with api_fingerprint.txt files,
we can use those for unbundled builds, but until then, just use the
PLATFORM_PREVIEW_SDK_VERSION as a placeholder.

MD5 was just the most convenient, since we don't have a sha tool that we
can use on Mac currently. I'm hoping we can get a toybox-based tool in
the future that standardizes that, but we aren't currently using sha*sum
from toybox on Linux, much less on Darwin yet.

Test: m dist out/dist/api_fingerprint.txt
Test: m out/target/product/.../system/build.prop
Change-Id: If69f270560d05135cb81a9bb2d1b208ea78f86df
2 files changed
tree: c95cc8a5748b03e0520f10cb443d21077f390c3f
  1. common/
  2. core/
  3. packaging/
  4. target/
  5. tests/
  6. tools/
  7. .gitignore
  8. Android.mk
  9. buildspec.mk.default
  10. Changes.md
  11. CleanSpec.mk
  12. envsetup.sh
  13. help.sh
  14. navbar.md
  15. OWNERS
  16. README.md
  17. tapasHelp.sh
  18. Usage.txt
README.md

Android Make Build System

This is the Makefile-based portion of the Android Build System.

For documentation on how to run a build, see Usage.txt

For a list of behavioral changes useful for Android.mk writers see Changes.md

For an outdated reference on Android.mk files, see build-system.html. Our Android.mk files look similar, but are entirely different from the Android.mk files used by the NDK build system. When searching for documentation elsewhere, ensure that it is for the platform build system -- most are not.

This Makefile-based system is in the process of being replaced with Soong, a new build system written in Go. During the transition, all of these makefiles are read by Kati, and generate a ninja file instead of being executed directly. That's combined with a ninja file read by Soong so that the build graph of the two systems can be combined and run as one.