How to make a 64-bit C++ DLL?

Question

I selected MachineX64 in the "Target Machine" of the property page of a C++ DLL project and then built it. I got the error "fatal error LNK1112: module machine type 'x86' conflicts with target machine type 'x64'". Why? In the "Platform" option, I chose 'Win32'.

My IDE is Visual Studio 2019 / Windows 10.

Answer 1

Hi,

We couldn't use a .cmd file shipped with VS for setting the environment variables but instead use our own equivalent .cmd file. That file set the %PATH% variable for 32-bit cl.exe and that's exactly why C++ source was compiled with a 32-bit compiler. The soluton is to iether use the .cmd for x64 compilation shipped with VS or to craft a custom .cmd file setting %PATH% appropriately.

And a more convenient way is that you can try to select "x64" instead of "win32".

Best Regards,

Jeanine

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