rust() and rust_mut() fails linking with MinGW gcc

[qwxxx]

My code:

impl MyObject{
        pub fn test(& self) ->Option<()>{
            println!("Hello!");
            Some(())
        }
    }
  impl qobject::MyObject {
      #[qinvokable]
      pub fn test_base(&self){
          unsafe{
              self.rust().test();
          }
      }
}

Output:

C:/Qt/Tools/mingw900_64/bin/../lib/gcc/x86_64-w64-mingw32/11.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: libvsb_terminal.a(my_object.cxx.o): in function `_ZN11QMetaObject12invokeMethodIZNK4rust9cxxqtlib111CxxQtThreadI8MyObjectE5queueIN16cxx_qt_my_object27MyObjectCxxQtThreadQueuedFnEEEvNS1_10cxxbridge12FnIFvRS4_NS9_3BoxIT_EEEEESE_EUlvE_EENSt9enable_ifIXaaaantsrN9QtPrivate15FunctionPointerISD_EE25IsPointerToMemberFunctioneqsrSL_13ArgumentCountLin1EntsrSt14is_convertibleISD_PKcE5valueEbE4typeEP7QObjectSD_N2Qt14ConnectionTypeEPDTclfL0p0_EE':
C:/Qt/6.2.4/mingw_64/include/QtCore/qobjectdefs.h:352: undefined reference to `__imp__ZN11QMetaObject16invokeMethodImplEP7QObjectPN9QtPrivate15QSlotObjectBaseEN2Qt14ConnectionTypeEPv'
collect2.exe: error: ld returned 1 exit status

It's working good with macos/clang with same code, but fails on windows/gcc.
What could be the reason?

[Be-ing]

Are you using CMake or building only with Cargo? GNU ld.bfd fails to link the qml-minimal-no-cmake example: #223

[Be-ing]

Can you try running cargo build -p qml-minimal-no-cmake in this repository?

[Be-ing]

We haven't been testing with MinGW, though maybe we should add that to CI...

[qwxxx]

Are you using CMake or building only with Cargo? GNU ld.bfd fails to link the qml-minimal-no-cmake example: #223

I'm using CMake 3.19 for build. All examples works, but when I add rust() or rust_mut(), this error happens.

[qwxxx]

Maybe there is another way to get access to rust object?

[ahayzen-kdab]

This seems odd how using rust/rust_mut causes the CxxQtThread queue stuff to have linker issues. We need to setup a MinGW environment to reproduce this and it would be good to have CI for that too.

For now does using MSVC work for you on Windows ? or is that not available for you ?

[qwxxx]

This seems odd how using rust/rust_mut causes the CxxQtThread queue stuff to have linker issues. We need to setup a MinGW environment to reproduce this and it would be good to have CI for that too.

For now does using MSVC work for you on Windows ? or is that not available for you ?

MSVC is not installed on my workstation yet, but I will do it soon

[qwxxx]

This seems odd how using rust/rust_mut causes the CxxQtThread queue stuff to have linker issues. We need to setup a MinGW environment to reproduce this and it would be good to have CI for that too.

For now does using MSVC work for you on Windows ? or is that not available for you ?

It looks like the problem is not in rust_mut(). the problem disappears when I remove the use of the qinvokable function in c++ code. Code with any functions compiles successfully as long as I don't use them in c++ code. With all this, using clang/macos and the same code, I can use all the functions without any problems

[Be-ing]

Can you link to your whole code repository?

[qwxxx]

Can you link to your whole code repository?

this is a commercial project, so I can't, unfortunately. I will try to make a minimal working project to reproduce the problem

[qwxxx]

I seem to have found the reason. It was necessary to add the line Qt::Qml to target_link_libraries, it is very strange that it depends on the platform and compiler, and i havent qml components in rust part.
target_link_libraries(${CRATE} INTERFACE Qt::Core Qt::Gui Qt::Qml#this line )

[Be-ing]

Yeah there can be some weird stuff with dependencies between Qt libraries. For example, on macOS, we have to link QtNetwork when QtQml is linked 🤷

cxx-qt/examples/cargo_without_cmake/build.rs

Line 20 in 6892f82

.qt_modules(&["Qml", "Network"])