Prepare for clang+mingw windows builds

Use $(prefix)CLANG_SUPPORTED from Soong to control whether to use clang
for host builds or not. It's fairly general, but I only expect it to be
used to so that Windows builds can be switched between GCC and Clang
with a single switch.

Also separate native-host-cross from native-host so that it's easier to
build all possible windows modules.

Bug: 69933068
Test: m native-host-cross
Test: switch clang on and off, grep w64.*g++ out/build-aosp_arm.ninja
Change-Id: I205c5bc6739b72a539ece935381107ec1dd5bd48
2 files changed
tree: a82c020a449ca15cb8c3bc4ca30811b79b977e43
  1. core/
  2. target/
  3. tests/
  4. tools/
  5. .gitignore
  6. Android.mk
  7. buildspec.mk.default
  8. Changes.md
  9. CleanSpec.mk
  10. envsetup.sh
  11. help.sh
  12. navbar.md
  13. OWNERS
  14. README.md
  15. tapasHelp.sh
  16. 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For an outdated reference on Android.mk files, see build-system.html.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.