infinite.c

// clang -std=c99 -O2 foo.c && ./a.out

#include <stdio.h>
#include <stdbool.h>

__attribute__((noinline)) void foo(bool b) {
  if (b) return; // remove this line and it will infinite loop
  while (1) {}
}

int main() {
  foo(false);
  puts("broken!");
}