7. valgrind - a Good Tool to Detect Memory Problems

valgrind can detect problems such as:
- Use of uninitialized memory.
- Reading/writing memory after it has been free'd.
- Reading/writing off the end of malloc'd blocks.
- Reading/writing inappropriate areas on the stack.
- Memory leaks -- where pointers to malloc'd blocks are lost forever.
- Passing of uninitialized and/or unaddressable memory to system calls.
- Mismatched use of malloc/new/new [] Vs free/delete/delete [].
- Some abuses of the POSIX pthreads API.
valgrind is very easy to use. It has many optional flags that you can learn about from the documentation. (valgrind -h).
A useful flag is --num-callers=NNN which sets how far back to print the function call sequence when an error is detected, (sometimes the error actually occurs in a sequence of functions you didn't write). By default it is --num-callers=4.