Linking to a MSVC DLL -- Undefined references?

[RogerBreton]

Open-Source MinGW 5.12
Console application
Need to link to existing MSVC DLL
Have corresponding .h and .lib -- nothing else, in both 32 and 64 bit

In main.cpp, I have call to a FDX_GetDevicePortList () function, which I know resides in FDX.DLL.

Here is compiler output :

cmd.exe /C "cd . && F:\Qt\Tools\mingw810_64\bin\g++.exe -g CMakeFiles/Console2.dir/Console2_autogen/mocs_compilation.cpp.obj CMakeFiles/Console2.dir/main.cpp.obj -o Console2.exe -Wl,--out-implib,libConsole2.dll.a -Wl,--major-image-version,0,--minor-image-version,0 F:/Qt/5.15.2/mingw81_64/lib/libQt5Core.a -lkernel32 -luser32 -lgdi32 -lwinspool -lshell32 -lole32 -loleaut32 -luuid -lcomdlg32 -ladvapi32 && cd ."

[JKSH]

@RogerBreton said in Linking to a MSVC DLL -- Undefined references?:

Open-Source MinGW
...
MSVC DLL

Unless the FDX.dll was written in C (or unless it has extern "C" in the headers), it is incompatible with MinGW. You must build your app with the same version of MSVC instead.

EDIT: In addition, you must use Qt DLLs that were built with the same version of MSVC, as explained at https://forum.qt.io/topic/125649/change-compiler-from-mingw-to-msvc-not-possible

[SGaist]

Hi,

@JKSH said in Linking to a MSVC DLL -- Undefined references?:

You must build your app with the same version of MSVC instead.

Just to add to that, MSVC versions used to be incompatible with each other until VS2017 which was backward compatible with 2015.