Is it undefined behavior to take the address of an uninitialized pointer?

Question

N1570 states that this is undefined behavior:

§J.2/1 The value of an object with automatic storage duration is used while it is indeterminate (6.2.4

Answer 1

See this example

char * ptr; 

Since ptr is not pointing to any object, dereferencing it invokes undefined behavior. But when you pass its address to strtol, having syntax

long int strtol(const char *nptr, char **endptr, int base);  

in statement

long parsed = strtol("11110111", &ptr, 2);   

the endptr parameter of strtol is pointing to object ptr and derefeencing it will not invoke any UB.