where is CAN_SEE_OBJ declared?

can_see_obj.txt

[~/src/SillyMUD/src]$ make
gcc -g -DIMPL_SECURITY -DNEW_RENT -DLEVEL_LOSS -DNEWEXP -DGROUP_NAMES -Werror -DIMPL_SECURITY -DNEW_RENT -DLEVEL_LOSS -DNEWEXP -DGROUP_NAMES  -c -o comm.o comm.c
comm.c:1514:18: error: implicit declaration of function 'CAN_SEE_OBJ' is invalid
      in C99 [-Werror,-Wimplicit-function-declaration]
          case 'o': i = OBJN(obj, to); 
                        ^
./utils.h:239:26: note: expanded from macro 'OBJN'
#define OBJN(obj, vict) (CAN_SEE_OBJ((vict), (obj)) ? \
                         ^
...
3 errors generated.
make: *** [comm.o] Error 1