#!/usr/sbin/dtrace -s
#pragma D option quiet

/* Usage: sudo ./trace_msg_send -p PID ClassNamePartial
 *
 * E.g. messages send to Xcode classes that start with `DVTiPhoneSimulator`:
 *
 *   $ sudo ./trace_msg_send -p $(pgrep '^Xcode$') DVTiPhoneSimulator
*/

/* From: http://stackoverflow.com/questions/16238845/show-objective-c-class-in-dtrace-output/16242756#16242756 */

unsigned long long indention;
int indentation_amount;

BEGIN {
  indentation_amount = 4;
}

objc$target:$1::entry
{
    method = (string)&probefunc[1];
    type = probefunc[0];
    class = probemod;
    printf("%*s%s %c[%s %s]\n", indention * indentation_amount, "", "->", type, class, method);
    indention++;
}
objc$target:$1::return
{
    indention--;
    method = (string)&probefunc[1];
    type = probefunc[0];
    class = probemod;
    printf("%*s%s %c[%s %s]\n", indention * indentation_amount, "", "<-", type, class, method);
}