Android IL2CPP clang++ crash

I know, IL2CPP for Android is currently unsupported, but for further stabilization I'd like to address this issue. I have a certain project that fails to compile with IL2CPP enabled because clang++ crashes. I'm building on Windows with the r10e 64bit NDK. I'm using the latest 5.4.0b7.

The command line of the crashing clang++ instance is as follows:

"D:\android-ndk-r10e\toolchains\llvm-3.6\prebuilt\windows\bin\clang++.exe" -cc1 -triple armv7-none-linux-androideabi -emit-obj -mrelax-all -mnoexecstack -disable-free -main-file-name Il2CppAttributes.cpp -mrelocation-model pic -pic-level 2 -mthread-model posix -mdisable-fp-elim -fmath-errno -masm-verbose -mconstructor-aliases -fuse-init-array -target-cpu cortex-a8 -target-feature +soft-float-abi -target-feature +neon -target-abi aapcs-linux -mfloat-abi soft -target-linker-version 2.24 -g -dwarf-column-info -ffunction-sections -fdata-sections -coverage-file "S:\UnityProject\Project\Temp/StagingArea\Il2Cpp\il2cppOutput\armeabi-v7a\Il2CppAttributes.o" -resource-dir "D:\android-ndk-r10e\toolchains\llvm-3.6\prebuilt\windows\bin\..\lib\clang\3.6" -D NDEBUG -I "U:\Unity 5.4.0b7\Editor\Data\PlaybackEngines\AndroidPlayer/Tools\bdwgc/include" -I "U:\Unity 5.4.0b7\Editor\Data\PlaybackEngines\AndroidPlayer/Tools\libil2cpp/include" -I "Temp/StagingArea\Il2Cpp\il2cppOutput" -I D:/android-ndk-r10e/sources/cxx-stl/gnu-libstdc++/4.9/include -I D:/android-ndk-r10e/sources/cxx-stl/gnu-libstdc++/4.9/include/backward -I D:/android-ndk-r10e/sources/cxx-stl/gnu-libstdc++/4.9/libs/armeabi-v7a/include -isysroot D:/android-ndk-r10e/platforms/android-9/arch-arm -internal-isystem D:/android-ndk-r10e/platforms/android-9/arch-arm/usr/local/include -internal-isystem "D:\android-ndk-r10e\toolchains\llvm-3.6\prebuilt\windows\bin\..\lib\clang\3.6\include" -internal-externc-isystem D:/android-ndk-r10e/platforms/android-9/arch-arm/include -internal-externc-isystem D:/android-ndk-r10e/platforms/android-9/arch-arm/usr/include -O0 -std=c++11 -fdeprecated-macro -fdebug-compilation-dir "S:\UnityProject\Project" -ferror-limit 19 -fmessage-length 0 -fvisibility hidden -fvisibility-inlines-hidden -mstackrealign -fno-rtti -fno-signed-char -fobjc-runtime=gcc -fcxx-exceptions -fexceptions -fdiagnostics-show-option -o "Temp/StagingArea\Il2Cpp\il2cppOutput\armeabi-v7a\Il2CppAttributes.o" -x c++ "Temp/StagingArea\Il2Cpp\il2cppOutput\Il2CppAttributes.cpp"

The Il2CppAttributes.cpp source file is nearly 27MB in size, maybe thats just too much for clang? It's using up nearly 1GB of RAM when it crashed.
I also have a really relaxed link.xml file that preserves almost anything from the .net runtime:

Code (csharp):

1. <linker>
2.     <assembly fullname="System" preserve="all" />
3.     <assembly fullname="mscorlib" preserve="all" />
4.     <assembly fullname="Mono.Security" preserve="all" />
5. </linker>

Maybe splitting up the generated attributes source file would improve the situation?

I'd be glad to help out further!

 

Hey Josh! You were right, I incorrectly assumed it was the 64bit NDK, it actually was the 32bit. I've now installed the 64bit NDK on windows but now Unity won't go beyond the il2cpp conversion stage, crashing immediately.I don't get the crash reporter so I've submitted via the bug reporter (will note down the issue# as soon as I get the feedback mail).

Looking into the logs it looks like Unity doesn't like the 64bit NDK, as it tries to launch the clang executeable from the 32bit NDK!

System.ComponentModel.Win32Exception: ApplicationName='D:/android-ndk-r10e/toolchains/llvm-3.6/prebuilt/windows/bin/clang++', CommandLine='-c "Temp/StagingArea\Il2Cpp\il2cppOutput\Bulk_Generics_3.cpp" -o "Temp/StagingArea\Il2Cpp\il2cppOutput\armeabi-v7a\Bulk_Generics_3.o" --sysroot "D:/android-ndk-r10e/platforms/android-9/arch-arm" -gcc-toolchain "D:/android-ndk-r10e/toolchains/arm-linux-androideabi-4.9/prebuilt/windows" -target armv7-none-linux-androideabi -O0 -fPIC -fdata-sections -ffunction-sections -Wa,--noexecstack -fno-rtti -std=c++11 -fstrict-aliasing -fvisibility=hidden -fvisibility-inlines-hidden -mfpu=neon -DNDEBUG -g -I "U:\Unity 5.4.0b7\Editor\Data\PlaybackEngines\AndroidPlayer/Tools\bdwgc/include" -I "U:\Unity 5.4.0b7\Editor\Data\PlaybackEngines\AndroidPlayer/Tools\libil2cpp/include" -I "Temp/StagingArea\Il2Cpp\il2cppOutput" -I "D:/android-ndk-r10e/sources/cxx-stl/gnu-libstdc++/4.9/include" -I "D:/android-ndk-r10e/sources/cxx-stl/gnu-libstdc++/4.9/include/backward" -I "D:/android-ndk-r10e/sources/cxx-stl/gnu-libstdc++/4.9/libs/armeabi-v7a/include"', CurrentDirectory=''

/edit01: The Preference dialog will enforce downloading of the 32bit NDK, 64bit NDK isn't supported at all?

 

I've "hacked" my NDK installation so Unity finds the 64bit clang binaries in the 32bit locations, and the clang crash is gone. So I assume this will go away when the 64bit NDK support is completed. Any ideas if it will come to the next 5.4 beta, too? Sadly, we have other issues with 5.3 that prevent us from using it and 5.2 has no IL2CPP support (yet?) :-/

Yet, compilation of these huge C++ source files does take a while (test project with 10 classes with 2500 attributed fields each approx. 10 Minutes per ABI, 48MB sized Il2CppAttributes.cpp), so maaaaaaybe everyones build times would benefit by splitting them and have multiple clangs work in parallel ;-)

 

You're right, for a decent sized project that actually has code and not just 25 artificially crafted classes there may be other files that keep compiling. Although I remember that the attributes source file is getting compiled pretty late, after all the other files, surviving the others for a long time. Anyways, thanks for the quick support and clarification!

 

I could verify that 5.3.3p2 is now supporting the 64bit NDK nicely, but I've got crashes in the IL2CPP internals now at runtime (see http://forum.unity3d.com/threads/5-...-metadatacache-getil2cpptypefromindex.390453/ - reported issue #777371). Did not verify with 5.4.0b9 yet but from looking at the release notes, it doesn't support the 64bit NDK just yet?