How to wrap a function that returns void * in c

Question

I am currently exploring a bit in the direction of function pointers in c, and I've mocked up a little example that I feel should work, but it instead produces a segmentation fault and I am not really sure why.

Here's the code I mocked up

void *new_testarr()
{
    void *testarr = malloc(4*sizeof(int));
    return testarr;
}

void *test_wrap(void *(*functionpointer)(void))
{
    return (*functionpointer);
}

int main(int argc, char const *argv[])
{
    int *arr = (int *) test_wrap(new_testarr);

    arr[0] = 1;
    arr[1] = 2;
    arr[2] = 3;
    arr[3] = 4;

    for (int i = 0; i < 4; i++)
    {
        printf("%d ", arr[i]);
    }
    printf("\n");

    free(arr);
    return 0;
}

I tested the function new_testarr() by itself and there was no problem, but as soon as I try to wrap it then a segmentation fault occurs. I also tried adding an ampersand when passing the function in test_wrap(), but the same thing happened.

Any guidance would be greatly appreciated.

Answer 1

return (*functionpointer); is taking a function pointer and returning it as a void*, which is not allowed. I think you meant to write return (*functionpointer)(); - call the function through its pointer.