Function without name

Question

I would like to know how to call this function? And where can i find it's implementation if it doesn't have name?

extern void (*_malloc_message)(const char* p1, const char* p2, const char* p3, const char* p4);

Answer 1

_malloc_message is a function pointer.

Somewhere in the code you will find the definition of a function whose prototype is like this:

void foo (const char* p1, const char* p2, const char* p3, const char* p4);

Then you assign the function to the function pointer like this:.

_malloc_message = foo;

and call it like this:

(*_malloc_message)(p1, p2, p3, p4);

The question is why you cannot call foo directly. One reason is that you know that foo needs to be called only at runtime.