<![CDATA[undefined reference to _imp_]]>Dear Forum,

I know that there are forum posts with similar topics but I did not found a solution so far.

I have an external .lib to include to my project. I am using MinGW 64bit and Qt 5.15.0
I used the function "Add Library", selected external and selected the .lib.

unix:!macx|win32: LIBS += -L$$PWD/./ -llibe9u_LSMD_x64

INCLUDEPATH += $$PWD/.
DEPENDPATH += $$PWD/.

Now I get multiple "undefinde reference to imp" errors. The supplier of the lib says that it was created using a cross compiler.

I found this:
https://stackoverflow.com/questions/30767553/undefined-reference-when-using-c11-qmake-flags

And added:

QMAKE_CXXFLAGS += -std=c++11
CONFIG += c++11

But that did not help.

The lib works with Visual Studio. I also tried Qt VS Tools, but that also generated LNK2019 errors.

Any help appreciated.

Thanks!
Dan

]]>https://forum.qt.io/topic/134430/undefined-reference-to-_imp_RSS for NodeTue, 28 Apr 2026 10:17:25 GMTThu, 17 Feb 2022 20:27:39 GMT60<![CDATA[Reply to undefined reference to _imp_ on Sat, 19 Feb 2022 14:00:35 GMT]]>@dansab said in undefined reference to _imp_:

Shouldn't a C or C++ compiler be able to recognize this?

How? You told the compiler that you're using a c++ function, but the library only exported the c name - how should a linker (not compiler btw) know about this - these are two different symbols for them.

]]>https://forum.qt.io/post/703290https://forum.qt.io/post/703290Sat, 19 Feb 2022 14:00:35 GMT<![CDATA[Reply to undefined reference to _imp_ on Sat, 19 Feb 2022 13:17:05 GMT]]>Hi JonB,

the problem was, that some .h were written in C, so this problem was solved by

extern "C"
{
#include...
}

This error message is incredible unspecific...
Shouldn't a C or C++ compiler be able to recognize this?

cheers,
Dan

]]>https://forum.qt.io/post/703287https://forum.qt.io/post/703287Sat, 19 Feb 2022 13:17:05 GMT<![CDATA[Reply to undefined reference to _imp_ on Thu, 17 Feb 2022 20:31:59 GMT]]>@dansab
Are these .lib files giving "imp..." warnings from MSVC and you are trying to link them with MinGW?

]]>https://forum.qt.io/post/703071https://forum.qt.io/post/703071Thu, 17 Feb 2022 20:31:59 GMT