Assertion Fail in elf32-arm.c:7827 when building for Android with IL2CPP

Hello,

I am trying to build my project with IL2CPP for Android, but I keep hitting strange issues and compiler errors that I have no idea how to fix or to even work out what could be causing them.

I have tried removing .NET assemblies from the project one by one, but it seems to be trigerred by the major one, which has a lot of dependencies and is very big on itself, so it takes long time to replicate (Unity's bug report team complained about this and asked for a smaller version, but I just can't reduce it any further, so I'm on my own).

Here's what I found:

• Happens with recent version of Unity (2018.1.9f)

• Compiling the same codebase with IL2CPP for Windows works

• The major library which triggers this doesn't have any P/Invoke methods, its dependencies do

• Compiling only the dependencies with link.xml works fine

• Seems like a potential bug in the NDK itself, specifically the linker which fails

• List item

The error output generates many assertion fails in the elf32-arm.c file on line 7827, the assert in that file is this:

 BFD_ASSERT ((got_displacement & 0xf0000000) == 0);

(whole source here: https://android.googlesource.com/toolchain/binutils/+/ndk-r13-beta1/binutils-2.25/bfd/elf32-arm.c )

I'm not sure what this does though and what could be potentially even causing it in my own code. I'd appreciate it if anyone has any ideas where to look or how I could isolate this.

Here's the error output from Unity Editor:

 stdout:
 Building libil2cpp.so with AndroidToolChain.
     Output directory: D:\Sync\Projects\Software\Applications\NeoS\Testing\IL2CPP_Bug3\Temp\StagingArea\assets\bin\Data\Native\armeabi-v7a
     Cache directory: D:\Sync\Projects\Software\Applications\NeoS\Testing\IL2CPP_Bug3\Library\il2cpp_android_armeabi-v7a\il2cpp_cache
 ObjectFiles: 1665 of which compiled: 0
 Total compilation time: 877 milliseconds.
 il2cpp.exe didn't catch exception: Unity.IL2CPP.Building.BuilderFailedException: C:\android-ndk-r13b\toolchains\llvm\prebuilt\windows-x86_64\bin\clang++ @"C:\Users\Tomas\AppData\Local\Temp\tmp5EF.tmp" -o "D:\Sync\Projects\Software\Applications\NeoS\Testing\IL2CPP_Bug3\Library\il2cpp_android_armeabi-v7a\il2cpp_cache\linkresult_F38F1A33880E1CAB2A23B46AA75CE1D0\libil2cpp.so" -shared -Wl,-soname,libil2cpp.so -Wl,--no-undefined -Wl,-z,noexecstack -Wl,--gc-sections -Wl,--build-id --sysroot "C:\android-ndk-r13b\platforms\android-16\arch-arm" -gcc-toolchain "C:\android-ndk-r13b\toolchains\arm-linux-androideabi-4.9\prebuilt\windows-x86_64" -target armv7-none-linux-androideabi -Wl,--wrap,sigaction -L "C:\android-ndk-r13b\sources\cxx-stl\gnu-libstdc++\4.9\libs\armeabi-v7a" -lgnustl_static -llog -Xlinker -Map="D:\Sync\Projects\Software\Applications\NeoS\Testing\IL2CPP_Bug3\Library\il2cpp_android_armeabi-v7a\il2cpp_cache\linkresult_F38F1A33880E1CAB2A23B46AA75CE1D0\libil2cpp.map" -rdynamic -fPIE -pie -fuse-ld=bfd.exe
 
 clang++.exe: warning: argument unused during compilation: '-pie'
 C:\android-ndk-r13b\toolchains\arm-linux-androideabi-4.9\prebuilt\windows-x86_64/lib/gcc/arm-linux-androideabi/4.9.x/../../../../arm-linux-androideabi/bin\ld.bfd.exe: BFD (binutils-2.25-0666073) 2.25.51.20141117 assertion fail /usr/local/google/buildbot/src/android/gcc/toolchain/build/../binutils/binutils-2.25/bfd/elf32-arm.c:7827
 C:\android-ndk-r13b\toolchains\arm-linux-androideabi-4.9\prebuilt\windows-x86_64/lib/gcc/arm-linux-androideabi/4.9.x/../../../../arm-linux-androideabi/bin\ld.bfd.exe: BFD (binutils-2.25-0666073) 2.25.51.20141117 assertion fail /usr/local/google/buildbot/src/android/gcc/toolchain/build/../binutils/binutils-2.25/bfd/elf32-arm.c:7827
 C:\android-ndk-r13b\toolchains\arm-linux-androideabi-4.9\prebuilt\windows-x86_64/lib/gcc/arm-linux-androideabi/4.9.x/../../../../arm-linux-androideabi/bin\ld.bfd.exe: BFD (binutils-2.25-0666073) 2.25.51.20141117 assertion fail /usr/local/google/buildbot/src/android/gcc/toolchain/build/../binutils/binutils-2.25/bfd/elf32-arm.c:7827
 
 < This repeats for a few hundred lines >
 
 C:\android-ndk-r13b\toolchains\arm-linux-androideabi-4.9\prebuilt\windows-x86_64/lib/gcc/arm-linux-androideabi/4.9.x/../../../../arm-linux-androideabi/bin\ld.bfd.exe: BFD (binutils-2.25-0666073) 2.25.51.20141117 assertion fail /usr/local/google/buildbot/src/android/gcc/toolchain/build/../binutils/binutils-2.25/bfd/elf32-arm.c:7827
 C:\android-ndk-r13b\toolchains\arm-linux-androideabi-4.9\prebuilt\windows-x86_64/lib/gcc/arm-linux-androideabi/4.9.x/../../../../arm-linux-androideabi/bin\ld.bfd.exe: BFD (binutils-2.25-0666073) 2.25.51.20141117 assertion fail /usr/local/google/buildbot/src/android/gcc/toolchain/build/../binutils/binutils-2.25/bfd/elf32-arm.c:7827
 clang++.exe: error: linker command failed with exit code 1 (use -v to see invocation)
 
 
    at Unity.IL2CPP.Building.CppProgramBuilder.PostprocessObjectFiles(IEnumerable`1 objectFiles, CppToolChainContext toolChainContext)
    at Unity.IL2CPP.Building.CppProgramBuilder.Build(IBuildStatistics& statistics)
    at Unity.IL2CPP.Building.Statistics.BuildingTestRunnerHelper.BuildAndLogStatsForTestRunner(CppProgramBuilder builder, IBuildStatistics& statistics)
    at il2cpp.Program.DoRun(String[] args)
    at il2cpp.Program.Run(String[] args)
    at il2cpp.Program.Main(String[] args)