Question

Objective-C’s runtime seems to be rather robust, so I was wondering if there’s a way to log the name of the function that called the current function (for debugging purposes).

My situation is that a bunch of things assign to a property, and rather than set a breakpoint and examine the call stack each time, I’d like to just NSLog the name of the function that is setting the property, along with the new value.

So is it possible to get access to the call stack at runtime?

Answer 1

Try this:

#include <execinfo.h>

void *addr[2];
int nframes = backtrace(addr, sizeof(addr)/sizeof(*addr));
if (nframes > 1) {
    char **syms = backtrace_symbols(addr, nframes);
    NSLog(@"%s: caller: %s", __func__, syms[1]);
    free(syms);
} else {
    NSLog(@"%s: *** Failed to generate backtrace.", __func__);
}