What will this C code do?

void main(){
int x=1;
printf("%d\n",x=2);
}

>>160
I said they cannot have no linkage

That really isn't clear. You might want to work on your grammar there buddy.

The only variables with no linkage are those declared at block scope

Again, that's incorrect. Those variables have to have some kind of linkage, otherwise, if I compile this C program against another C program, I could access those variables in that block.