GDB, break condition, check NULL pointer

Question

I want to set a break point, and only stop at it, when one pointer called rc is NULL.

I did like that

      b task.c:190 if rc==NULL

but gdb says, NULL would be unrecognized, so I changed to

      b task.c:190 if(!rc)

which seems worked.

But I am not very sure, correct me if I am doing wrong.

Answer 1

try to re-compile your project with CFLAG -ggdb3, then set the break point.Or use (void *)0 instead of NULL

Answer 2

NULL is a C macro whose value is set to 0 Probably the gdb is not able to resolve the macro value.