How to find memory leak?

[MastAvalons]

 class A {
   public :
         list< string> getList (){
                list< string> l;
                l.push_back ("str1");
                l.push_back ("str2");
....
          return l;
         }
}

A * a = new A();
list l = a->getList();

I'm working on readymade code, which has a memory leak. How to find exactly where the memory is not freed and there is a leak?

[thines01]

There are a few tools to do that, but the first thing you should do is see that you are deleting any dynamically created variables when they are no longer necessary.

[mike_2000_17]

Well, from the code you posted, if there is no delete a; after, then there is clearly a memory leak there. How I found that memory leak: I opened my eyes and looked, that's a good trick.

Seriously though, finding memory leaks can be a very difficult if you have a large code-base to plow through.

One great tool for this is Valgrind. I think VS also has decent tools for that, but I haven't tried them.

All in all, the best remedy for memory leaks is prevention. For instance, designing software with ownership relationships in mind.

Another, somewhat desperate, trick is to just make a file-search for the keyword "new" and for each one, make sure it is either immediately wrapped in a smart-pointer (with automatic storage) or that it has a corresponding "delete" (and that any deep-copy or reallocations clean up the old storage correctly).