Changelog r24

Changelog

Report issues to GitHub.

For Android Studio issues, follow the docs on the Android Studio site.

Announcements

• The GNU Assembler (GAS), has been removed. If you were building with -fno-integrated-as you'll need to remove that flag. See Clang Migration Notes for advice on making assembly compatible with LLVM.

• GDB has been removed. Use LLDB instead. Note that ndk-gdb uses LLDB by default, and Android Studio has only ever supported LLDB.

• Jelly Bean (APIs 16, 17, and 18) is no longer supported. The minimum OS supported by the NDK is KitKat (API level 19).

• Non-Neon devices are no longer supported. A very small number of very old devices do not support Neon so most apps will not notice aside from the performance improvement.

• RenderScript build support has been removed. RenderScript was deprecated in Android 12. If you have not finished migrating your apps away from RenderScript, NDK r23 LTS can be used.

Changes

• Includes Android 12.1 APIs.
• Updated LLVM to clang-r433403, based on LLVM 13 development.
  • Issue 1590: Fix LLDB help crash.
• Issue 1559: Added LOCAL_ALLOW_MISSING_PREBUILT option to PREBUILT_SHARED_LIBRARY and PREBUILT_STATIC_LIBRARY which defers failures for missing prebuilts to build time. This enables use cases within AGP where one module provides "pre" built libraries to another module.

Known Issues

This is not intended to be a comprehensive list of all outstanding bugs.

• Issue 360: thread_local variables with non-trivial destructors will cause segfaults if the containing library is dlcloseed. This was fixed in API 28, but code running on devices older than API 28 will need a workaround. The simplest fix is to stop calling dlclose. If you absolutely must continue calling dlclose, see the following table:

  	Pre-API 23	APIs 23-27	API 28+
  No workarounds	Works for static STL	Broken	Works
  -Wl,-z,nodelete	Works for static STL	Works	Works
  No dlclose	Works	Works	Works

  If your code must run on devices older than M (API 23) and you cannot use the static STL (common), the only fix is to not call dlclose, or to stop using thread_local variables with non-trivial destructors.

  If your code does not need to run on devices older than API 23 you can link with -Wl,-z,nodelete, which instructs the linker to ignore dlclose for that library. You can backport this behavior by not calling dlclose.

  The fix in API 28 is the standardized inhibition of dlclose, so you can backport the fix to older versions by not calling dlclose.

• Issue 988: Exception handling when using ASan via wrap.sh can crash. To workaround this issue when using libc++_shared, ensure that your application's libc++_shared.so is in LD_PRELOAD in your wrap.sh as in the following example:

  #!/system/bin/sh
  HERE="$(cd "$(dirname "$0")" && pwd)"
  export ASAN_OPTIONS=log_to_syslog=false,allow_user_segv_handler=1
  ASAN_LIB=$(ls $HERE/libclang_rt.asan-*-android.so)
  if [ -f "$HERE/libc++_shared.so" ]; then
      # Workaround for https://github.com/android/ndk/issues/988.
      export LD_PRELOAD="$ASAN_LIB $HERE/libc++_shared.so"
  else
      export LD_PRELOAD="$ASAN_LIB"
  fi
  "$@"

  There is no known workaround for libc++_static.

  Note that because this is a platform bug rather than an NDK bug this cannot be fixed with an NDK update. This workaround will be necessary for code running on devices that do not contain the fix, and the bug has not been fixed even in the latest release of Android.