Function without name

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);


2 Answers
2

It isn't a function. It's a declaration saying that _malloc_message is a pointer to a function, with return type void and the parameters as given.

_malloc_message

void

In order to use it, you'd have to assign to it the address of a function with that arity, return type, and parameter types.

Then you'd use _malloc_message as if it were a function.

_malloc_message

_malloc_message

_malloc_message is a function pointer.

_malloc_message

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);

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;

_malloc_message = foo;

and call it like this:

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

(*_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.

extern

Thanks for contributing an answer to Stack Overflow!

But avoid …

To learn more, see our tips on writing great answers.

Some of your past answers have not been well-received, and you're in danger of being blocked from answering.

Please pay close attention to the following guidance:

But avoid …

To learn more, see our tips on writing great answers.

Required, but never shown

Required, but never shown

By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.