can't build HelloWorld on windows (llvm 12.0.1)

[kiwings]

when I try to build HelloWorld project with VS2019, I got LINK error( my cmake command is: cmake -G "Visual Studio 16 2019" -A x64 -Thost=x64 ../):

if I modify add_llvm_library MODULE to SHARED, VS2019 can successfully compile the HelloWolrd

but got the following warning:

and then opt.exe failed to load passes

In addition, the cmake invocation for llvm is:
cmake -DLLVM_ENABLE_PROJECTS="clang;lld;libcxx;llvm" -DLLVM_EXPORT_SYMOBLS_FOR_PLUGINS=On -G "Visual Studio 16 2019" -A x64 -Thost=x64 ..\

[banach-space]

Hi, thanks for visiting and creating this issue!

I don't have access to a Windows machine, so I won't be too helpful. But this error message is pretty clear, so I would just replace SHARED with MODULE. See:

• https://github.com/llvm/llvm-project/blame/main/llvm/lib/Transforms/Hello/CMakeLists.txt#L13-L20 (similar example inside llvm-project/llvm)
• https://cmake.org/cmake/help/latest/command/add_library.html (CMake documentation for MODULE and SHARED)

I hope that this will solve your problem! But please keep in mind that the support for plugins on Windows is a rather grey area.

-Andrzej

[kiwings]

thanks for your reply, Finally solved this problem by modifying the hellowolrd code.
It seems that the demo does not conform to llvm12.0.1.

but I can't can't directly using -load-pass-plugin ./HelloWorld.dll -passes=hello to load HelloWolrd.dll, I need to copy the HelloWorld.dll to the LLVM_DIR\bin, and then use command LLVM_DIR\bin\opt.exe -load=HelloWolrd.dll -hello -disable-output input_for_hello.dll

[banach-space]

What modifications did you have to make?

[kiwings]

I just deleted the code about New pass manager .
After trying again, it was not a code compatibility problem, The problem is that New pass manager has no way to compile to a dll on windows(Maybe I haven't found the right way).

[banach-space]

Thanks for sharing. I suspect that the required symbols are not exported.

So are you using the legacy pass manager and everything works fine for you on Windows?