#undef example

In this example, the script file has numerous #ifdef DEBUG statements to conditionally compile debug code. You want to use the debug code for only one section in the file, so you #define DEBUG at the beginning of the section, and #undef DEBUG at the end:

...

#define DEBUG

// Some code

#ifdef DEBUG

   // Debug code 

#endif

   // More code

#undef DEBUG

...

// Some more code

#ifdef DEBUG

   // More debug code 

#endif