Gcc optimization problem

I have a problem in STM32CubeIDE.

​

unsigned char readKey (void)
{
	volatile unsigned char keyValue=HAL_GPIO_ReadPin (KEY_GPIO_Port, KEY_Pin);
	if (0 == keyValue)
	{
		printf ("before delay\r\n");
		HAL_Delay (10);
		keyValue=HAL_GPIO_ReadPin (KEY_GPIO_Port, KEY_Pin);
		if (0 == keyValue)
		{
			printf ("after delay\r\n");
			return 1;
		}
	}
	return 0;
}

​

These codes will be OK in keil. But the STM32CubeIDE will not be able to print characters. My optimization level is -O0.