Changelog

Report issues to GitHub.

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

Announcements

GNU binutils, excluding the GNU Assembler (GAS), has been removed. GAS will be removed in the next release. If you are building with -fno-integrated-as, file bugs if anything is preventing you from removing that flag.
Support for GDB has ended. GDB will be removed from the next release. Use LLDB instead. Note that ndk-gdb uses LLDB by default.
NDK r23 is the last release that will support non-Neon. Beginning with NDK r24, the armeabi-v7a libraries in the sysroot will be built with Neon. A very small number of very old devices do not support Neon so most apps will not notice aside from the performance improvement.
Jelly Bean (APIs 16, 17, and 18) will not be supported in the next NDK release. The minimum OS supported by the NDK for r24 will be KitKat (API level 19).

Changes

Includes preview Android S Beta 2 APIs.
Updated LLVM to clang-r416183b, based on LLVM 12 development.
- Issue 1047: Fixes crash when using ASan with the CFI unwinder.
- Issue 1096: Includes support for Polly. Enable by adding -mllvm -polly to your cflags.
- Issue 1230: LLVM's libunwind is now used instead of libgcc for all architectures rather than just 32-bit Arm.
- Issue 1231: LLVM's libclang_rt.builtins is now used instead of libgcc.
- Issue 1406: Fixes crash with Neon intrinsic.
Vulkan validation layer source and binaries are no longer shipped in the NDK. The latest are now posted directly to GitHub.
Vulkan tools source is also removed, specifically vulkan_wrapper. It should be downloaded upstream from GitHub.
The toolchain file (android.toolchain.cmake) is refactored to base on cmake's integrated Android support. This new toolchain file will be enabled by default for cmake 3.21 and newer. No user side change is expected. But if anything goes wrong, please file a bug and set ANDROID_USE_LEGACY_TOOLCHAIN_FILE=ON to restore the legacy behavior.
Issue 929: find_library now prefers shared libraries from the sysroot over static libraries.
Issue 1390: ndk-build now warns when building a static executable with the wrong API level.
Issue 1452: NDK_ANALYZE=1 now sets APP_CLANG_TIDY=true rather than using scan-build. clang-tidy performs all the same checks by default, and scan-build was no longer working. See the bug for more details, but no user-side changes should be needed.

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 on devices running M or newer, or devices before M when using a static STL. The simple workaround is to not call dlclose.
Issue 906: Clang does not pass -march=armv7-a to the assembler when using -fno-integrated-as. This results in the assembler generating ARMv5 instructions. Note that by default Clang uses the integrated assembler which does not have this problem. To workaround this issue, explicitly use -march=armv7-a when building for 32-bit ARM with the non-integrated assembler, or use the integrated assembler. ndk-build and CMake already contain these workarounds.
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 workaround will be necessary for this use case to work on all devices until at least Android R.