1.2.8 $CHECKPOINTER : Check pointer values

The {$CHECKPOINTER} directive turns heap pointer checking on (value ON) or off (value OFF). If heap pointer checking is on and the code is compiled with the -gh (heaptrace) option on, then a check is inserted when dereferencing a pointer. The check will verify that the pointer contains a valid value, i.e. points to a location that is reachable by the program: the stack or a location in the heap. If not, a run-time error 216 or 204 is raised.

If the code is compiled without -gh switch, then this directive has no effect. Note that this considerably slows down the code.