Valgrind喜欢Mac OS 10.7（Lion）上的工具

I need a tool which helps me to find memory leaks in a c program in a similar way valgrind does. It should figures out when a program overwrites memory it should not (e.g. by miscalculating an array index). I learned that there is the leaks utility along with the graphical instruments app. I need a tool which helps me to find memory lea