How to use the @vue/runtime-dom.warn function in @vue/runtime-dom

} else {
      __DEV__ && warn(`invalid template option: `, template)
      return NOOP
    }
  }

  const key = template
  const cached = compileCache[key]
  if (cached) {
    return cached
  }

  if (template[0] === '#') {
    const el = document.querySelector(template)
    if (__DEV__ && !el) {
      warn(`Template element not found or is empty: ${template}`)
    }
    template = el ? el.innerHTML : ``
  }

  const { code } = compile(template, {
    hoistStatic: true,
    onError(err: CompilerError) {
      if (__DEV__) {
        const message = `Template compilation error: ${err.message}`
        const codeFrame =
          err.loc &&
          generateCodeFrame(
            template as string,
            err.loc.start.offset,
            err.loc.end.offset
          )

function compileToFunction(
  template: string | HTMLElement,
  options?: CompilerOptions
): RenderFunction {
  if (!isString(template)) {
    if (template.nodeType) {
      template = template.innerHTML
    } else {
      __DEV__ && warn(`invalid template option: `, template)
      return NOOP
    }
  }

  const key = template
  const cached = compileCache[key]
  if (cached) {
    return cached
  }

  if (template[0] === '#') {
    const el = document.querySelector(template)
    if (__DEV__ && !el) {
      warn(`Template element not found or is empty: ${template}`)
    }
    template = el ? el.innerHTML : ``

onError(err: CompilerError) {
      if (__DEV__) {
        const message = `Template compilation error: ${err.message}`
        const codeFrame =
          err.loc &&
          generateCodeFrame(
            template as string,
            err.loc.start.offset,
            err.loc.end.offset
          )
        warn(codeFrame ? `${message}\n${codeFrame}` : message)
      }
    },
    ...options