Unable to compile dll files

Hi,

I attempted to test this on my system for learning purposes but for some reason I am not able to build the evil DLL's As you already are aware the docker image is offline but I attempted to compile one of the files manually.

Any suggestions or clarification why the below will fail?

Compile command:"

$ x86_64-w64-mingw32-gcc -shared -mwindows -o winmm.dll winmm.dll.c winmm.dll.def

Errors:

winmm.dll.c:64:7: error: conflicting types for ‘mmioSeek’; have ‘void *()’
   64 | VOID *mmioSeek(){ generate_fingerprint(__func__); }
      |       ^~~~~~~~
In file included from /usr/share/mingw-w64/include/mmsystem.h:26,
                 from /usr/share/mingw-w64/include/windows.h:86,
                 from winmm.dll.c:1:
/usr/share/mingw-w64/include/mmiscapi.h:222:22: note: previous declaration of ‘mmioSeek’ with type ‘LONG(struct HMMIO__ *, LONG,  int)’ {aka ‘long int(struct HMMIO__ *, long int,  int)’}
  222 | WINMMAPI LONG WINAPI mmioSeek(HMMIO hmmio, LONG lOffset, int iOrigin);
      |                      ^~~~~~~~
winmm.dll.c:65:7: error: conflicting types for ‘midiInGetID’; have ‘void *()’
   65 | VOID *midiInGetID(){ generate_fingerprint(__func__); }
      |       ^~~~~~~~~~~
In file included from /usr/share/mingw-w64/include/mmsystem.h:29:
/usr/share/mingw-w64/include/mmeapi.h:609:26: note: previous declaration of ‘midiInGetID’ with type ‘MMRESULT(struct HMIDIIN__ *, UINT *)’ {aka ‘unsigned int(struct HMIDIIN__ *, unsigned int *)’}
  609 | WINMMAPI MMRESULT WINAPI midiInGetID(HMIDIIN hmi, LPUINT puDeviceID);
      |                          ^~~~~~~~~~~
winmm.dll.c:66:7: error: conflicting types for ‘mciFreeCommandResource’; have ‘void *()’
   66 | VOID *mciFreeCommandResource(){ generate_fingerprint(__func__); }
      |       ^~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/share/mingw-w64/include/mmsystem.h:23:
/usr/share/mingw-w64/include/mciapi.h:868:18: note: previous declaration of ‘mciFreeCommandResource’ with type ‘WINBOOL(UINT)’ {aka ‘int(unsigned int)’}
  868 | WINBOOL APIENTRY mciFreeCommandResource(UINT wTable);
      |                  ^~~~~~~~~~~~~~~~~~~~~~
winmm.dll.c:67:7: error: conflicting types for ‘midiInGetErrorTextW’; have ‘void *()’
   67 | VOID *midiInGetErrorTextW(){ generate_fingerprint(__func__); }
      |       ^~~~~~~~~~~~~~~~~~~
/usr/share/mingw-w64/include/mmeapi.h:598:26: note: previous declaration of ‘midiInGetErrorTextW’ with type ‘MMRESULT(MMRESULT,  WCHAR *, UINT)’ {aka ‘unsigned int(unsigned int,  short unsigned int *, unsigned int)’}
  598 | WINMMAPI MMRESULT WINAPI midiInGetErrorTextW(MMRESULT mmrError, LPWSTR pszText, UINT cchText);

wietze / windows-dll-hijacking

Unable to compile dll files #6