Compiling dll's

I'm trying to build a dll using WineLib.  The source compiles fine under windows.  When I try to compile it with winelib, I get this error:

c++ -shared -Wl,-rpath,/usr/local/lib -Wl,-Bsymbolic -o liberrh_auto.dll.so  errh.o errhReg.o  liberrh_auto.dll.spec.o      -lwine -lwine_unicode -lwine_uuid -lm
liberrh_auto.dll.spec.o: In function `LoadStringW':
liberrh_auto.dll.spec.o(.data+0x188): undefined reference to `DllMain'

My spec file only contains this line: init    DllMain

And DllMain is defined in errh.cpp as (it's not prototyped in errh.h):
BOOL APIENTRY DllMain( HINSTANCE h,DWORD d, LPVOID l)

Any help?

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Steve Lustbader