For example: #ifdef DEBUG /* Only execute this if debugging */ printf("Example debug output "); #endif /* def DEBUG */ With multiple levels of #ifs, this can simplify the code considerably (particularly with the addition of comments on the #else lines. The function below can be used to automate this process. It will also highlight (with a comment containing 'XXX') any inaccurate comments (for example a /* def DEBUG */ linked to a #ifndef DEBUG). A more advanced version of this code, with a (slightly buggy) Brace Commenter as well, is available as a plugin from