Shouldn't this: ANTLR3_API pANTLR3_INPUT_STREAM antlr3AsciiFileStreamNew(pANTLR3_UINT8 fileName); Really be this: ANTLR3_API pANTLR3_INPUT_STREAM antlr3AsciiFileStreamNew(const pANTLR3_UINT8 fileName); ? -- Gary R. Van Sickle