I am really OCD about maintaining strict column limits, and not a fan of "\" line continuation because you can't put a comment after it, so here is my method.
//|¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯|//
#ifdef CONDITION_01 //| |//
#define TEMP_MACRO //| |//
#endif //| |//
#ifdef CONDITION_02 //| |//
#define TEMP_MACRO //| |//
#endif //| |//
#ifdef CONDITION_03 //| |//
#define TEMP_MACRO //| |//
#endif //| |//
#ifdef TEMP_MACRO //| |//
//|- -- -- -- -- -- -- -- -- -- -|//
printf("[IF_CONDITION:(1|2|3)]\n");
//|- -- -- -- -- -- -- -- -- -- -|//
#endif //| |//
#undef TEMP_MACRO //| |//
//|________________________________________|//