Moving the kernel to modern C

I'm not sure we're speaking about the same thing. I'm speaking about not making this monstrosity possible, where I'd say "good luck" for figuring the type of "i" depending on the line you're reading, and its bounds:

#include <stdio.h>
#include <unistd.h>

int blah(long x, int j)
{
long i = x ? x : -1;
int k = i;

for (int i = 1; i < j; i++) {
k += i * 2;
char i = (k & 1) ? 'O' : 'E';
int pid = getpid();
printf("i=%d j=%d pid=%d\n", i, j, pid);
}
return k;
}

PS: sorry for the formatting, I didn't find how to make a code block.