c/c++: Automatically initialize pointers to null in visual studio

Question

I understand that overhead is involved in automatically initializing uninitialized pointers to null. But I am ready for this overhead; so how can I make Visual Studio 2010 C++ compiler to set all uninitialized pointers to null.

Please note I don't need smart pointer solution as I am debugging existing application.

Answer 1

I'm not aware of any such feature, and I've never heard of anybody looking for it before.

This seems like a very dangerous path to take.

What happens when you write your code to just assume that uninitialised pointers are null pointers, then you migrate your code to a new installation of your IDE, or give it to someone else? You will be propagating hard-to-find UB bugs. Not good!

Instead:

• turn on warnings for uninitialised variables
• initialise those variables

Or, for debugging existing broken code, use the fact that Visual Studio gives uninitialised data with automatic storage duration the underlying byte pattern 0xCC. Look for this value, rather than 0x00.

• When and why will an OS initialise memory to 0xCD, 0xDD, etc. on malloc/free/new/delete?

Answer 2

You can create a class with this behavior, something like:

template <typename T>
class Ptr
{
public:
    Ptr() = default;
    Ptr(T*ptr) : ptr(ptr) {}
    // ...
    operator T*&() {return ptr;}
private:
    T* ptr = nullptr;
};