On 22.09.2018 02:58, Robin Templeton wrote: > Hi Tim, > > Tim Gesthuizen <tim.gesthui...@yahoo.de> writes: > >> As you can see from the output, clang is missing some include paths that >> gcc has. Specifying a custom `CPLUS_INCLUDE_PATH' fixes the problem: >> >> ┌──── >> │ >> CPLUS_INCLUDE_PATH=$HOME/.guix-profile/include/c++:$HOME/.guix-profile/include/c++/x86_64-unknown-linux-gnu/ >> clang++ test.cc >> │ ./a.out >> └──── >> >> ┌──── >> │ Hello, World >> └──── >> >> This is already done in the package definition for the >> `C_INCLUDE_PATH'. It is not done for C++ because clang does not >> implement a feature or build system variable for changing it. >> >> Fixing this problem would probably include an upstream patch enabling a >> similar feature for C++ for what is already done in C and configuring >> this variable in build phase to add the same include paths that g++ has. > > Another solution, maybe simpler than a new environment variable, is to > have clang use the C++ include path from its gcc input. On FHS systems, > clang can find C++ headers using the GCC_INSTALL_PREFIX configure > option, but it doesn't work under Guix because the GCC package puts > headers and libraries in separate outputs. Guix already patches clang to > hardcode some library directories; maybe something similar could be done > for C++ headers. (I think the function to modify for this would be > Linux::addLibStdCxxIncludePaths in lib/Driver/ToolChains/Linux.cpp.) >
Hi Robin, I also found that section and the environment variable while debugging clang. I did not know about that variable even though its documented and Guix uses it. I've created a debug build of clang for investigating and pointing GCC_INSTALL_PREFIX to the GCC input and not the lib part fixes the problem for me. I don't know from where this build pulls crt1.o. I will try changing GCC_INSTALL_PREFIX in the guix package definition and see whether that fixes the bug. Tim.
