Cross-compiling ROOT, but LLVM issues

[kratsg]

Hi, when I try to cross-compile ROOT, I get the following CMake error: https://gist.github.com/kratsg/10cf7835a83d4f17ad93173c8655c8e9

However, I notice that LLVM-Config.cmake exists, but it appears case-sensitive. This is the LLVM recipe I’m relying on (http://cgit.openembedded.org/meta-openembedded/tree/meta-oe/recipes-core/llvm/llvm3.3_3.3.bb?h=master) as using root 6.04.12 with the built-in LLVM doesn’t allow for C++11 compilation.

Any ideas?

[mato]

Cross-compiling is most probably not working for ROOT at this moment. If people want to contribute we are more than happy to help.
In your particular case, I do not understand how you reach the point of failure since the builtin_llvm option is by default ON and will not try to locate LLVM anywhere. What version of ROOT are you using?

[kratsg]

Hi mato,

I overrode the build option to turn it off in my local configuration to try and link to an existing LLVM… Unfortunately, if I use 6.04.12 – and disable built-in LLVM, I get the above error. If I enable the built-in LLVM, I have complaints that the built-in LLVM doesn’t support stdc++11 flag… so then I tried 6.08.04 which gave me the following error about libatomic https://gist.github.com/kratsg/027c92d0b020a594c9669a04f1457ed0 .

You can see the (simple) recipes here: https://github.com/kratsg/meta-l1calo/tree/master/recipes-core/root

Giordon

[pcanal]

overrode the build option to turn it off in my local configuration to try and link to an existing LLVM…

ROOT/Cling requires to use the libraries coming from the builtin version of LLVM (but can be compiled with any version that supports C++11).

When you see
| CMake Error at interpreter/llvm/src/cmake/modules/CheckAtomic.cmake:52 (message): | Host compiler appears to require libatomic, but cannot find it. | Call Stack (most recent call first): | interpreter/llvm/src/cmake/config-ix.cmake:317 (include) | interpreter/llvm/src/CMakeLists.txt:458 (include) |
What is the host compiler?

[kratsg]

Hi,

kratsg@dc:~$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/5/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 5.4.0-6ubuntu1~16.04.4' --with-bugurl=file:///usr/share/doc/gcc-5/README.Bugs --enable-languages=c,ada,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-5 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-libmpx --enable-plugin --with-system-zlib --disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-5-amd64/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-5-amd64 --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-5-amd64 --with-arch-directory=amd64 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --enable-objc-gc --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.4)