Compiling Qt5 from source for Clang

jdenozi

Qt 5.15.2 for clang
I'm trying to compile the Qt5.15.2 from source code for clang usage (need C++20 for the project).
I already done it on Ubuntu 20 and know trying on Ubuntu 22 without any success.

What I've done :

(1) LLVM installation :

Getting source code :

git clone https://github.com/llvm/llvm-project.git

Configure and build:

cd llvm-project &&
mkdir build     &&
cd build        &&
cmake -S ../llvm                           \\
-B .                                       \\
-G Ninja                                   \\
-DLLVM_ENABLE_PROJECTS=clang               \\
-DLLVM_ENABLE_RUNTIMES="libcxx;libcxxabi"  \\
-DCMAKE_INSTALL_PREFIX=/usr/local/         \\
-DCMAKE_BUILD_TYPE=Release                 \\

cmake --build . parallel

(2) Qt installation

Download : https://download.qt.io/archive/qt/5.15/5.15.2/single/qt-everywhere-src-5.15.2.tar.xz
Download dependencies like xorg etc...
Setting installation prefix to

/opt/qt5

Then configure

./configure -prefix /opt/qt5 -platform linux-clang-libc++ -linker ldd

(3) Error encountered
Unfortunately I can't configure because I have linker error.

Creating qmake...
./usr/bin/ld : /usr/bin/ld: DWARF error: invalid or unhandled FORM value: 0x23
qlogging.o : dans la fonction « std::__throw_bad_array_new_lengthabi:v15000 » :
qlogging.cpp:(.text._ZSt28__throw_bad_array_new_lengthB6v15000v[_ZSt28__throw_bad_array_new_lengthB6v15000v]+0x1a) : référence indéfinie vers « std::bad_array_new_length::bad_array_new_length() »
/usr/bin/ld : /usr/bin/ld: DWARF error: invalid or unhandled FORM value: 0x23
qsettings.o : dans la fonction « std::__1::unique_lock<QMutex>::unlock() » :
qsettings.cpp:(.text._ZNSt3__111unique_lockI6QMutexE6unlockEv[_ZNSt3__111unique_lockI6QMutexE6unlockEv]+0x2b) : référence indéfinie vers « std::__1::__throw_system_error(int, char const*) »
/usr/bin/ld : qsettings.o : dans la fonction « std::__1::unique_lock<QMutex>::lock() » :
qsettings.cpp:(.text._ZNSt3__111unique_lockI6QMutexE4lockEv[_ZNSt3__111unique_lockI6QMutexE4lockEv]+0x2b) : référence indéfinie vers « std::__1::__throw_system_error(int, char const*) »
/usr/bin/ld : qsettings.cpp:(.text._ZNSt3__111unique_lockI6QMutexE4lockEv[_ZNSt3__111unique_lockI6QMutexE4lockEv]+0x4a) : référence indéfinie vers « std::__1::__throw_system_error(int, char const*) »
/usr/bin/ld : /usr/bin/ld: DWARF error: invalid or unhandled FORM value: 0x23
qstring.o : dans la fonction « void std::__1::__sort_impl[abi:v15000]<std::__1::_ClassicAlgPolicy, int*, std::__1::__less<int, int> >(int*, int*, std::__1::__less<int, int>&) » :
qstring.cpp:(.text.ZNSt3__111__sort_implB6v15000INS_17_ClassicAlgPolicyEPiNS_6__lessIiiEEEEvT0_S5_RT1[ZNSt3__111__sort_implB6v15000INS_17_ClassicAlgPolicyEPiNS_6__lessIiiEEEEvT0_S5_RT1]+0x53) : référence indéfinie vers « void std::__1::__sort<std::__1::__less<int, int>&, int*>(int*, int*, std::__1::__less<int, int>&) »
clang-16: error: linker command failed with exit code 1 (use -v to see invocation)

My gcc seems to be ok:

Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/11/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none:amdgcn-amdhsa
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 11.2.0-19ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-11/README.Bugs --enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++,m2 --prefix=/usr --with-gcc-major-version-only --program-suffix=-11 --program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-plugin --enable-default-pie --with-system-zlib --enable-libphobos-checking=release --with-target-system-zlib=auto --enable-objc-gc=auto --enable-multiarch --disable-werror --enable-cet --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none=/build/gcc-11-gBFGDP/gcc-11-11.2.0/debian/tmp-nvptx/usr,amdgcn-amdhsa=/build/gcc-11-gBFGDP/gcc-11-11.2.0/debian/tmp-gcn/usr --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu --with-build-config=bootstrap-lto-lean --enable-link-serialization=2
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 11.2.0 (Ubuntu 11.2.0

What should I do ?

kkoehne

Does it succeed if you don't pass -linker ldd to configure?

jdenozi

@kkoehne No ... doesn't change anything unfortunately. Seems ldd isn't called at all and ld is call by default.