Highly recommend this tool for debugging memory leaks from a core file. It can dump all allocations in the heap among other things. If you regularly debug complex core files, this is a must have. (Note: I used the Linux command line version.)
This tool is truly a wonderful tool for analyzing coredump, especially memory related errors. It is able to reveal much valuable info from core file which GDB can't. It's a complementary tool to GDB. I strongly recommend this tool.