[Pierre-Marie Baty]

C++ name decoration doesn't produce the same results in GCC and in Microsoft's CL. Why it works when another DLL sits in between is because since botman discovered how to build our custom exports list to hook single-player games correctly (through FUNC_FROM_NAME and NAME_FOR_FUNCTION redirects) we've building all our hook DLLs this way. Why it doesn't when no DLL sits in between is because the engine still relies on its own FUNC_FROM_NAME and NAME_FOR_FUNCTION facilities which expect Microsoft C++ style mangling.

This problem exists because of the way extra entity methods are exported in HL1 game DLLs. HL2 shouldn't have this problem. However, I wouldn't be surprised if you cannot use MinGW at all. The only solution may be to build your own exports list, like botman and myself were doing.