#include <metal_stdlib>
using namespace metal;

#define TINT_ISOLATE_UB(VOLATILE_NAME) \
  volatile bool VOLATILE_NAME = true; \
  if (VOLATILE_NAME)

int f() {
  int i = 0;
  {
    TINT_ISOLATE_UB(tint_volatile_true) while(true) {
      i = (i + 1);
      if ((i > 4)) {
        return i;
      }
      {
      }
      continue;
    }
  }
  /* unreachable */
}