This sounds more like the option would keep GCC from automatically defining certain macros that it would normally define by default (GCC defines certain default macros before ever parsing any source code), but that are not "standard", rather than undefining macros that you have explicitly defined on the command line. If that's the correct interpretation of this argument, then it is behaving as expected with respect to your macro. -----Original Message----- From: Bansidhar Arvind Deshpande - CTD, Chennai. [mailto:bansidhara@xxxxxxxxxxxxxxx] Sent: Thursday, October 16, 2003 2:50 AM To: GNU GCC Subject: C preprocessor problem continuing my previous mail. (I regret the inconvenience) GNU manual says about -undef as follows -undef Do not predefine any nonstandard macros. I am using gcc 2.96
