Changelog

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

Announcements

• 32-bit Windows is no longer supported. This does not affect the vast majority of users. If you do still need to build NDK apps from 32-bit versions of Windows, continue using NDK r20.

  For more information on this change within Android Developer tools, see the blog post on the topic.

• macOS 10.8 is no longer supported as of r21b (r21 supports 10.8). macOS 10.15 requires that binaries be notarized, and notarization is only supported for binaries built for 10.9 or newer.

• LLD is now available for testing. AOSP has switched to using LLD by default and the NDK will follow (timeline unknown). Test LLD in your app by passing -fuse-ld=lld when linking. Note that Issue 843 will affect builds using LLD with binutils strip and objcopy as opposed to llvm-strip and llvm-objcopy.

• The legacy toolchain install paths will be removed before the next LTS release (likely in r22). These paths have been obsolete since NDK r19 and take up a considerable amount of space in the NDK. The paths being removed are:

  • platforms
  • sources/cxx-stl
  • sysroot
  • toolchains (with the exception of toolchains/llvm)

  In general this change should only affect build system maintainers, or those using build systems that are not up to date. ndk-build and the CMake toolchain users are unaffected, and neither are make_standalone_toolchain.py users (though that script has been unnecessary since r19).

  For information on migrating away from the legacy toolchain layout, see the Build System Maintainers Guide for the NDK version you're using.

• The Play Store will require 64-bit support when uploading an APK beginning in August 2019. Start porting now to avoid surprises when the time comes. For more information, see this blog post.

Changes

• Updated Clang and LLD to r365631.

  • Issue 855: LLD no longer hangs when using multithreaded linking on Windows.
  • Issue 884: Clang no longer passes -faddrsig by default.
  • Issue 859: Clang now default to using Neon for all 32-bit Android Arm targets.
    • If your minSdkVersion is 23 or higher, or if you were already enabling Neon manually, this change does not affect you.
    • CPUs that do not support this feature are uncommon.
    • If you need to continue supporting these devices you can disable Neon explicitly by setting LOCAL_ARM_NEON := false in ndk-build or passing -DANDROID_ARM_NEON=false to CMake.
    • Alternatively, use the Play Console to blacklist CPUs without Neon to disallow your app from being installed on those devices.
  • Issue 1004: Fixed bug with bad line number information when building Arm64 with -O0.
  • Issue 1028: OpenMP is now available in both static and shared variants. Note that shared is the default behavior, but in prior NDK releases the static library would be used because there was no shared library. To keep the old behavior, link with -static-openmp.

• Updated libc++ to r369764.

• Updated make to 4.2.1.

  • Modified ndk-build to supply -O for more readable errors with parallel builds.
  • abspath now works properly with Windows drive letters, so if you‘re using the workaround similar to what’s found in the NDK samples, you‘ll need to either drop the workaround or make sure it’s only used prior to r21.

• Updated glibc to 2.17.

• Updated gdb to 8.3.

• Issue 885: For LLD+LLDB compatibility, the NDK build systems now pass -Wl,--build-id=sha1 instead of -Wl,--build-id when using LLD. Note that the CMake toolchain does not have access to flags set in CMakeLists.txt, so using an explicit -fuse-ld=lld instead of ANDROID_LD=lld will produce output that cannot be debugged with Android Studio. Third-party build systems need to apply the workaround manually. For more details, see the Build System Maintainers Guide.

• Fixed ndk-build to use Clang's default C++ standard version (currently C++14) when using libc++.

• Removed the cxx-stl/system module from ndk-build. The system STL is still available (for now, see Issue 744); only an implementation detail has been removed. If you were explicitly linking libstdc++ or importing cxx-stl/system, remove that and ensure that APP_STL is set to system instead.

• Issue 976: ndk-build and the CMake toolchain file now enable _FORTIFY_SOURCE by default. See FORTIFY in Android for more details.

• Added NDK_GRADLE_INJECTED_IMPORT_PATH support to ndk-build. This is to support import of dependencies from AAR dependencies. See Issue 916 for more information.

• Added NDK_MAJOR, NDK_MINOR, NDK_BETA, NDK_CANARY, and ndk-major-at-least APIs to ndk-build. These can be used to check what version of the NDK you are using from within ndk-build (CMake already has equivalent APIs). The first three are integers, NDK_CANARY is either true or false, and ndk-major-at-least is a function that takes a single integer. For example, to check if your build is being performed with NDK r21 or newer:

  # This check works even on pre-r21 NDKs. The function is undefined pre-r21,
  # and calling an undefined function in make returns the empty string, which
  # is not equal to "true", so the else branch will be taken.
  ifeq ($(call ndk-major-at-least,21),true)
      # Using at least NDK r21.
  else
      # Using something earlier than r21.
  endif
  

  Note that because this API was not available before r21, it cannot be used to determine which NDK version earlier than 21 is being used.

• Issue 1092: Fixed hiding of unwinder symbols in outputs of ndk-build and CMake. Maintainers of third-party build systems should apply similar fixes when using NDK r19 and above to guard against possible future compatibility issues.

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 70838247: Gold emits broken debug information for AArch64. AArch64 still uses BFD by default.

• 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 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/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.

• This version of the NDK is incompatible with the Android Gradle plugin version 3.0 or older. If you see an error like No toolchains found in the NDK toolchains folder for ABI with prefix: mips64el-linux-android, update your project file to use plugin version 3.1 or newer. You will also need to upgrade to Android Studio 3.1 or newer.

• Issue 843: Using LLD with binutils strip or objcopy breaks RelRO.