http://www.mingw.org/wiki/msvc_and_mingw_dlls
MinGW調用VC：
The other way is to produce the .a files for GCC. For __cdecl functions (in most cases), it is simple: you only need to apply the reimp tool from Anders Norlander (since his web site is no longer available, you may choose to download
[this version|http://wyw.dcweb.cn/download.asp?path=&file=reimp_new.zip]
enhanced by Jose Fonseca):
reimp testdll.lib gcc -o testmain testmain.c -L. -ltestdll