> How can I tell gcc/cpp to warn on (or in some other way point out) unused > preprocessor defines? What do you mean by unused? Used but never set/defined (eg by configure) or defined but not present in any #ifdef DEFINE=XX #endif ? If it's the second case you can use a simple tool such as grep to get a list of all defines (filter ^#define ..) Then you can remove those found files from the code base and grep the result. If there are no occurences left it's safe to remove it.. If there are you have to manually check wither the occurences are in comments etc. So perhaps this helps you find of all not used defines. Marc Weber
